Cognitive performance
Supplements studied for cognitive performance.
Overview
Cognitive performance has extensive supplement research in this database. Tyrosine (16 studies) may improve memory, reaction time, and stress-related cognition in healthy adults under acute stressors. Panax Ginseng may help attention and reaction time in middle-aged adults but not consistently in younger groups.
L-Theanine may boost focus at single 100 mg doses and, with caffeine, alertness and accuracy. Rhodiola is marked possibly effective without a detailed summary here. Caffeine shows modest benefits for processing speed, attention, and memory in available research. See the heatmap and evidence reviews below for population and dose detail.
Effect graph
Relevant supplements
Relevant supplements sorted by DEX Score.
| Theanine | ★★★★★ | Medium |
| Panax Ginseng | ★★★★★ | Medium |
| Rhodiola | ★★★★★ | Medium |
| Tyrosine | ★★★★★ | Low |
| Taurine | ★★★★★ | Low |
| Multivitamin | ★★★★★ | Low |
| Kava | ★★★★★ | Low |
| Guarana | ★★★★★ | Low |
| Ginkgo | ★★★★★ | Low |
| Bacopa | ★★★★★ | Low |
| Nattokinase | ★★★★★ | Low |
| Lutein | ★★★★★ | Low |
| L-Carnitine | ★★★★★ | Low |
| Vitamin D | ★★★★★ | Low |
| Lion's Mane Mushroom | ★★★★★ | Low |
| Green Tea | ★★★★★ | Low |
| American Ginseng | ★★★★★ | Low |
| Zeaxanthin | ★★★★★ | Low |
| Vitamin A | ★★★★★ | Low |
| Hawthorn | ★★★★★ | Low |
| Flaxseed Oil | ★★★★★ | Low |
| Eleuthero | ★★★★★ | Low |
| Elderberry | ★★★★★ | Low |
| Avocado | ★★★★★ | Low |
| Alpha-Linolenic Acid | ★★★★★ | Low |
| Yerba Mate | ★★★★★ | Low |
| Olive Oil | ★★★★★ | Low |
| Lycopene | ★★★★★ | Low |
| Ginger | ★★★★★ | Low |
| Cocoa | ★★★★★ | Very Low / None |
| Caffeine | ★★★★★ | Low |
| Algal Oil | ★★★★★ | Very Low / None |
| Yohimbe | ★★★★★ | Very Low / None |
| Vitamin B2 (Riboflavin) | ★★★★★ | Very Low / None |
| Saccharomyces boulardii | ★★★★★ | Very Low / None |
| Resveratrol | ★★★★★ | Very Low / None |
| Beta-Alanine | ★★★★★ | Very Low / None |
Studies
Find individual evidence reviews for supplements sorted by DEX Score.
37 supplements for , and rated at least stars. All purchase bands. No minimum star filter.
TheanineView supplement →
Consider purchase·★★★★★
How we scored this▸
- L-theanine might help improve focus and attention, especially with a single 100 mg dose.
- Taking 200 mg daily for a month doesn’t seem to help memory or thinking skills much, except maybe a little for people with lower mental sharpness.
- When combined with caffeine, L-theanine can boost alertness and accuracy on tests requiring attention switching, but it doesn’t speed up reaction time.
- It’s not clear if these benefits come from L-theanine, caffeine, or both, and some research suggests taking them together isn’t better than taking either one alone.
Browse 7 studies·1 meta-analysis
RCTEffects of L-theanine-caffeine combination on sustained attention and inhibitory control among children with ADHD: a proof-of-concept neuroimaging RCT2020
A crossover RCT of 5 boys with ADHD found L-theanine plus caffeine improved cognition and inhibitory control on neuroimaging tasks, though caffeine alone worsened inhibitory control.
- Effect
- Benefit
- Dose
- 2.5 mg/kg
- Population
- Children/adolescents
- Ages
- 8–15
RCTEffects of L-Theanine Administration on Stress-Related Symptoms and Cognitive Functions in Healthy Adults: A Randomized Controlled Trial2019n=30
An RCT of 30 healthy adults found that 200 mg/day L-theanine for 4 weeks significantly reduced trait anxiety, depression, and PSQI sleep scores and improved verbal fluency versus placebo.
- Effect
- Benefit
- Duration
- 4 weeks
- Dose
- 200 mg/day
- Population
- Healthy adults
- Participants
- 30
- Avg age
- 48.3±11.9
MetaAcute effects of tea constituents L-theanine, caffeine, and epigallocatechin gallate on cognitive function and mood: a systematic review and meta-analysis2014
A meta-analysis of 11 studies found L-theanine plus caffeine improved alertness and attentional switching in the first 2 hours, with caffeine showing stronger effects than L-theanine alone.
- Effect
- Benefit
RCTAssessing the effects of caffeine and theanine on the maintenance of vigilance during a sustained attention task2012n=27
In 27 adults over a 2-hour SART vigilance task, caffeine 50 mg plus theanine 100 mg reduced error rates over time versus placebo; caffeine alone lowered tonic alpha power, but neither alone improved all attention measures.
- Effect
- Benefit
- Duration
- 4 days
- Dose
- 50 mg
- Population
- Adults
- Participants
- 27
RCTL-theanine and caffeine improve task switching but not intersensory attention or subjective alertness2010n=29
In 29 adults, combined L-theanine 97 mg and caffeine 40 mg improved task-switching accuracy versus placebo; caffeine or theanine alone did not significantly change subjective alertness or intersensory attention.
- Effect
- Benefit
- Dose
- 97 mg
- Population
- Healthy adults
- Participants
- 29
RCTThe combination of L-theanine and caffeine improves cognitive performance and increases subjective alertness2010n=44
In 44 young adults, L-theanine 97 mg plus caffeine 40 mg significantly improved task-switching accuracy and self-reported alertness while reducing tiredness versus placebo over 70–120 minutes.
- Effect
- Benefit
- Dose
- 40 mg/day
- Population
- Young adults
- Participants
- 44
RCTThe combined effects of L-theanine and caffeine on cognitive performance and mood2008n=27
A study of 27 healthy participants found that 50 mg caffeine improved subjective alertness at 60 min following consumption and accuracy on an attention-switching task at 90 minutes following consumption. However, those taking 100 mg L-theanine in combination with caffeine improved both speed and accuracy on the attention-switching task after 60 minutes and improved focus at 60 and 90 minutes after ingestion. An L-theanine and caffeine combination may improve cognitive test performance and improve focus compared to either intervention alone.
- Effect
- Benefit
- Dose
- 50 mg/day
- Population
- Healthy adults
- Participants
- 27
Panax GinsengView supplement →
Consider purchase·★★★★★
How we scored this▸
- Taking Panax ginseng may help improve thinking skills, attention, and reaction time in middle-aged adults but does not seem to benefit younger adults.
- Panax ginseng alone does not improve memory, but when combined with ginkgo leaf extract, it might help memory in healthy middle-aged people or those with mild brain fatigue.
- Different forms and doses have been tested for up to 12 weeks with positive effects on some brain functions.
Browse 8 studies
RCTPanax ginseng (G115) improves aspects of working memory performance and subjective ratings of calmness in healthy young adults2010n=30
In 30 healthy adults, 200–400 mg/day Panax ginseng G115 for 8 days improved working memory and mood versus placebo, with dose- and time-dependent effects.
- Effect
- Benefit
- Duration
- 8 days
- Dose
- 400 mg/day
- Population
- Healthy adults
- Participants
- 30
- Avg age
- ~23
RCTEffects of Panax ginseng, consumed with and without glucose, on blood glucose levels and cognitive performance during sustained 'mentally demanding' tasks2006n=27
In 27 healthy adults, 200 mg ginseng G115 with or without glucose did not consistently improve cognitive performance on a demand test battery.
- Effect
- Benefit
- Dose
- 200 mg ginseng
- Population
- Young adults
- Participants
- 27
RCTSingle doses of Panax ginseng (G115) reduce blood glucose levels and improve cognitive performance during sustained mental activity2005n=30
In 30 healthy adults, single doses of 200–400 mg Panax ginseng G115 improved serial subtraction and mental fatigue scores and lowered blood glucose versus placebo.
- Effect
- Benefit
- Dose
- 200–400 mg/day
- Population
- Young adults
- Participants
- 30
Controlled trialImproved cognitive performance in human volunteers following administration of guarana (Paullinia cupana) extract: comparison and interaction with Panax ginseng2004
In a crossover trial, guarana extract improved cognitive performance, with additional benefit when combined with Panax ginseng versus placebo.
- Effect
- Benefit
- Dose
- 9 mg
RCTAcute, dose-dependent cognitive effects of Ginkgo biloba, Panax ginseng and their combination in healthy young volunteers: differential interactions with cognitive demand2002
In healthy young adults, acute ginkgo, ginseng, and their combination produced task-dependent improvements in serial arithmetic performance versus placebo.
- Effect
- Benefit
- Dose
- 320 mg/day
- Population
- Young adults
- Avg age
- ~21
RCTDifferential, dose dependent changes in cognitive performance following acute administration of a Ginkgo biloba/Panax ginseng combination to healthy young volunteers2001
In 20 healthy young adults, acute Ginkgo/ginseng combinations (320–960 mg) produced dose-related cognitive improvements on some computerized tests, with 320 mg superior to placebo on day 90.
- Effect
- Benefit
- Dose
- 320–960 mg/day
- Population
- Young adults
RCTThe memory enhancing effects of a Ginkgo biloba/Panax ginseng combination in healthy middle-aged volunteers2000
In 256 healthy middle-aged volunteers, a ginkgo (60 mg) plus ginseng (100 mg) combination for 14 weeks significantly improved memory and cognitive test performance versus placebo.
- Effect
- Benefit
- Duration
- 14 weeks
- Dose
- 160 mg 2×/day
- Population
- Adults
Controlled trial[Effect of a standardized ginseng extract on general well-being, reaction time, lung function and gonadal hormones]1981
A German study of standardized ginseng extract reported improvements in general well-being, reaction time, lung function, and gonadal hormones versus placebo in healthy subjects.
- Effect
- Benefit
- Population
- Healthy adults
RhodiolaView supplement →
Consider purchase·★★★★★
How we scored this▸
- Rhodiola is possibly effective for Cognitive performance.
Browse 4 studies·1 meta-analysis
RCTEffects of Rhodiola rosea supplementation on mental performance, physical capacity, and oxidative stress biomarkers in healthy men2018n=26
In hospitalized patients on antibiotics, S. boulardii reduced AAD incidence versus placebo in a single-center randomized trial.
- Effect
- Benefit
- Duration
- 4 weeks
- Dose
- 600 mg/day
- Population
- Men
- Participants
- 26
RCTA randomized trial of two different doses of a SHR-5 Rhodiola rosea extract versus placebo and control of capacity for mental work2003
In 180 hospitalized patients, S. boulardii reduced antibiotic-associated diarrhea to 9.5% versus 22% on placebo.
- Effect
- Benefit
- Ages
- 19–21
RCTA double-blind, placebo-controlled pilot study of the stimulating and adaptogenic effect of Rhodiola rosea SHR-5 extract on the fatigue of students caused by stress during an examination period with a repeated low-dose regimen2000
A meta-analysis of 9 probiotic trials found S. boulardii and lactobacilli reduced antibiotic-associated diarrhea versus placebo.
- Effect
- Benefit
- Duration
- 20 days
RCTRhodiola rosea in stress induced fatigue--a double blind cross-over study of a standardized extract SHR-5 with a repeated low-dose regimen on the mental performance of healthy physicians during night duty2000
Updated IDSA/SHEA guidelines recommend probiotics only selectively for C. difficile prevention; S. boulardii evidence was noted but not strongly endorsed.
- Effect
- Benefit
BacopaView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Studies on Bacopa’s effects on thinking and memory show mixed results.
- Overall, taking 300 to 600 mg daily for at least 12 weeks does not clearly improve memory, learning, attention, or reaction time compared with placebo.
- Some smaller studies suggest Bacopa might help speed up thinking, improve memory recall, and help with learning in healthy adults.
- Bacopa taken with other ingredients like ginseng and coffee fruit extract showed small improvements in memory and attention shortly after taking it, but it’s unclear if Bacopa alone caused this.
- Another study using a combination of Bacopa, ginkgo, and vitamins for 12 weeks didn’t find clear benefits, except possibly for attention in people already eating a healthy diet.
Browse 19 studies·2 meta-analyses
RCTEvaluating the effects of Bacopa monnieri on cognitive performance and sleep quality of patients with mild cognitive impairment: A triple-blinded, randomized, placebo-controlled trial2024n=62
A triple-blind RCT of 62 mild cognitive impairment patients found 160 mg bacopa twice daily for 2 months improved attention and verbal fluency but not overall cognitive score or sleep quality.
- Effect
- Benefit
- Duration
- 2 months
- Dose
- 160 mg/day
- Population
- MCI patients
- Participants
- 62
RCTBacopa monnieri supplementation has no effect on serum brain-derived neurotrophic factor levels but beneficially modulates nuclear factor kappa B and cyclic AMP response element-binding protein levels in healthy elderly subjects2023n=35
An open-label study of 35 healthy older adults (ages 60–78) found 3 months of bacopa improved delayed recall and modulated CREB and NF-κB signaling without changing total MoCA or serum BDNF.
- Effect
- Benefit
- Duration
- 3 months
- Population
- Older adults
- Participants
- 35
- Ages
- 60–78
RCTInvestigating the effects of a multinutrient supplement on cognition, mood and biochemical markers in middle-aged adults with 'optimal' and 'sub-optimal' diets: A randomized double-blind placebo-controlled trial2022n=35
A 12-week RCT of 141 middle-aged adults found a multinutrient formula with bacopa raised B vitamin status but did not improve memory overall, though attention improved in those with optimal baseline diets.
- Effect
- No Benefit
- Duration
- 12 weeks
- Population
- Adults
- Participants
- 35
- Ages
- 40–65
MetaThe effectiveness of Bacopa monnieri (Linn.) Wettst. as a nootropic, neuroprotective, or antidepressant supplement: analysis of the available clinical data2021
A systematic review meta-analysis found bacopa showed modest cognitive improvements in healthy adults and memory-loss patients, but no two studies showed significant gains on the same tests.
- Dose
- 200 mg/day
- Population
- Healthy adults
RCTThe Neurocognitive Effects of Bacopa monnieri and Cognitive Training on Markers of Brain Microstructure in Healthy Older Adults2021n=28
A 12-week RCT of 28 adults over 55 found bacopa plus cognitive training slowed reaction time on some tasks and increased neurite dispersion on MRI, conflicting with behavioral gains.
- Effect
- No Benefit
- Duration
- 12 weeks
- Population
- Healthy adults
- Participants
- 28
- Ages
- 55+
RCTAcute effects of combined Bacopa, American ginseng and whole coffee fruit on working memory and cerebral haemodynamic response of the prefrontal cortex: a double-blind, placebo-controlled study2019n=40
In 40 healthy adults, a single dose of Bacopa, American ginseng, and coffee fruit improved N-back accuracy and prefrontal cortex activation versus placebo at 45 minutes.
- Effect
- Benefit
- Population
- Healthy adults
- Participants
- 40
- Ages
- 18–60
RCTEfficacy of standardized extract of Bacopa monnieri (Bacognize®) on cognitive functions of medical students: a six-week, randomized placebo-controlled trial2016
A 6-week double-blind RCT of 60 medical students found 300 mg/day Bacognize bacopa significantly improved cognitive test performance versus placebo.
- Effect
- Benefit
- Duration
- 15 days
- Dose
- 300 mg/day
- Population
- Women
- Ages
- 19–22
MetaMeta-analysis of randomized controlled trials on cognitive effects of Bacopa monnieri extract2014n=437
A meta-analysis of 9 bacopa RCTs in 518 subjects found improved cognition on Trail B (−17.9 ms) and choice reaction time (−10.6 ms) after ≥12 weeks of supplementation.
- Effect
- Benefit
- Duration
- 12 weeks
- Population
- Dementia patients
- Participants
- 437
RCTAn acute, double-blind, placebo-controlled crossover study of 320 mg and 640 mg doses of a special extract of Bacopa monnieri (CDRI 08) on sustained cognitive performance2013n=24
An acute crossover study of 24 healthy adults found 320 mg bacopa improved performance on early repetitions of a cognitive demand battery without affecting cardiovascular or stress ratings.
- Effect
- Benefit
- Dose
- 640 mg/day
- Population
- Healthy adults
- Participants
- 24
RCTBrahmi for the better? New findings challenging cognition and anti-anxiety effects of Brahmi (Bacopa monniera) in healthy adults2013
A 12-week RCT of 72 healthy adults (ages 35–60) found 450 mg/day bacopa did not improve learning, memory, or attention versus placebo, with only a trend toward lower state anxiety.
- Effect
- No Benefit
- Dose
- 450 mg/day
- Population
- Adults
- Ages
- 35–60
RCTEffects of 12-week Bacopa monnieri consumption on attention, cognitive processing, working memory, and functions of both cholinergic and monoaminergic systems in healthy elderly volunteers2012
A 12-week RCT of 60 healthy older adults found 300–600 mg/day bacopa improved working memory and reduced N100/P300 latencies, partly via suppressed plasma AChE activity.
- Effect
- Benefit
- Duration
- 12 weeks
- Dose
- 300–600 mg
- Population
- Older adults
- Avg age
- ~63
RCTDoes Bacopa monnieri improve memory performance in older persons? Results of a randomized, placebo-controlled, double-blind trial2010n=98
A 12-week RCT of 98 healthy adults over 55 found 300 mg/day BacoMind improved verbal learning and delayed recall on the AVLT, with gastrointestinal side effects.
- Effect
- Benefit
- Duration
- 12 weeks
- Dose
- 300 mg/day
- Population
- Healthy adults
- Participants
- 98
- Ages
- 55+
RCTEffects of a standardized Bacopa monnieri extract on cognitive performance, anxiety, and depression in the elderly: a randomized, double-blind, placebo-controlled trial2008n=10
A 12-week RCT of 48 adults aged 65+ found 300 mg/day bacopa improved delayed verbal recall and Stroop performance and reduced anxiety and depression scores versus placebo.
- Effect
- Benefit
- Duration
- 12 weeks
- Dose
- 300 mg/day
- Population
- Older adults
- Participants
- 10
RCTExamining the nootropic effects of a special extract of Bacopa monniera on human cognitive functioning: 90 day double-blind placebo-controlled randomized trial2008n=107
A 90-day double-blind RCT of 107 healthy adults found 300 mg/day KeenMind bacopa improved spatial working memory accuracy and reduced false positives on a rapid visual processing task.
- Effect
- Benefit
- Duration
- 90 days
- Dose
- 300 mg/day
- Population
- Healthy adults
- Participants
- 107
RCTRandomized controlled trial of standardized Bacopa monniera extract in age-associated memory impairment2006
A 12-week RCT in age-associated memory impairment found 125 mg bacopa twice daily improved mental control, logical memory, and paired-associate learning versus placebo.
- Effect
- Benefit
- Duration
- 12 weeks
- Dose
- 125 mg 2×/day
- Population
- Healthy adults
- Ages
- 55+
RCTChronic effects of Brahmi (Bacopa monnieri) on human memory2002n=76
A 3-month RCT of 76 adults aged 40–65 found bacopa improved retention of new information without affecting learning rate, attention, or everyday memory function.
- Effect
- Benefit
- Population
- Adults
- Participants
- 76
- Ages
- 40–65
RCTThe acute effects of an extract of Bacopa monniera (Brahmi) on cognitive function in healthy normal subjects2001n=20
An acute RCT of 38 healthy adults found a single 300 mg bacopa dose produced no significant cognitive changes 2 hours after dosing, suggesting benefits require chronic use.
- Effect
- No Benefit
- Dose
- 300 mg
- Population
- Healthy adults
- Participants
- 20
RCTThe chronic effects of an extract of Bacopa monniera (Brahmi) on cognitive function in healthy human subjects2001
A 12-week RCT found 300 mg/day KeenMind bacopa improved visual information processing speed, learning rate, memory consolidation, and state anxiety versus placebo.
- Effect
- Benefit
- Duration
- 12 weeks
- Dose
- 300 mg
Efficacy of Bacopa monniera in revitalizing intellectual functions in children1987
An early 1987 clinical study reported bacopa improved memory, attention, and learning in children with cognitive deficits, but no abstract or quantitative outcome data are available.
- Effect
- Benefit
- Population
- Children/adolescents
GinkgoView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Oral ginkgo may improve recall in healthy young adults and healthy middle-aged adults but most studies are limited.
- Overall, the research does not support a meaningful benefit.
Browse 13 studies
RCTInvestigating the Effects of a Multinutrient Supplement on Cognition, Mood and Biochemical Markers in Middle-Aged Adults with 'Optimal' and 'Sub-Optimal' Diets: A Randomized Double Blind Placebo Controlled Trial2022n=141
A 12-week RCT of 141 middle-aged adults found a multinutrient formula with bacopa raised B vitamin status but did not improve memory overall, though attention improved in those with optimal baseline diets.
- Effect
- No Benefit
- Duration
- 12 weeks
- Population
- Adults
- Participants
- 141
- Ages
- 40–65
RCTSpecific memory effects of Ginkgo biloba extract EGb 761 in middle-aged healthy volunteers2011n=188
In 188 healthy adults aged 45–56, ginkgo EGb 761 240 mg/day for 6 weeks significantly improved free-recall memory performance versus placebo.
- Effect
- Benefit
- Duration
- 6 weeks
- Dose
- 240 mg/day
- Population
- Healthy adults
- Participants
- 188
- Ages
- 45–56
RCTGinkgo biloba extract EGb 761(R), donepezil or both combined in the treatment of Alzheimer's disease with neuropsychiatric features: a randomised, double-blind, exploratory trial2009n=96
In 96 Alzheimer patients with neuropsychiatric features, ginkgo EGb 761 240 mg/day was comparable to donepezil for cognitive improvement over 22 weeks in an exploratory trial.
- Effect
- Benefit
- Duration
- 22 weeks
- Dose
- 240 mg/day
- Population
- Older adults
- Participants
- 96
- Avg age
- ~50
RCTAcute cognitive effects of standardised Ginkgo biloba extract complexed with phosphatidylserine2007
In 28 healthy young adults, acute ginkgo 120 mg did not significantly improve cognitive or mood outcomes versus placebo regardless of phosphatidylserine complexation.
- Effect
- No Benefit
- Dose
- 120 mg/day
- Population
- Healthy adults
RCTDangshen (Codonopsis pilosula) and Bai guo (Gingko biloba) enhance learning and memory2004n=60
In 60 healthy adults, ginkgo biloba combined with Codonopsis pilosula for several weeks improved memory acquisition and retention versus placebo in a double-blind trial.
- Effect
- Benefit
- Dose
- 80 mg/day ginkgo biloba
- Population
- Healthy adults
- Participants
- 60
- Ages
- 21–60
RCTEffects of a combined extract of Ginkgo biloba and Bacopa monniera on cognitive function in healthy humans2004n=85
In 85 healthy adults, a ginkgo (120 mg) plus Bacopa monniera (300 mg) combination for 2–4 weeks did not significantly improve cognitive performance versus placebo.
- Effect
- No Benefit
- Duration
- 4 weeks
- Dose
- 120 mg
- Population
- Healthy adults
- Participants
- 85
RCTGincosan (a combination of Ginkgo biloba and Panax ginseng): the effects on mood and cognition of 6 and 12 weeks' treatment in post-menopausal women2004n=30
In 57 post-menopausal women, Gincosan (ginkgo 120 mg plus ginseng 200 mg) for 12 weeks improved memory and mood scores versus placebo.
- Effect
- No Benefit
- Duration
- 12 weeks
- Dose
- 320 mg/day
- Population
- Women
- Participants
- 30
- Ages
- 51–66
RCTCognitive performance, SPECT, and blood viscosity in elderly non-demented people using Ginkgo biloba2003n=48
In 48 men aged 60–70, ginkgo biloba extract for several months improved some cognitive test scores and SPECT perfusion patterns versus placebo.
- Effect
- Benefit
- Duration
- 8 months
- Population
- Older adults
- Participants
- 48
- Ages
- 60–70
RCTA double-blind, placebo-controlled, randomized trial of Ginkgo biloba extract EGb 761 in a sample of cognitively intact older adults: neuropsychological findings2002n=131
In 131 cognitively intact older adults, ginkgo EGb 761 180 mg/day for 6 weeks did not significantly improve neuropsychological test performance versus placebo.
- Effect
- No Benefit
- Duration
- 6 weeks
- Dose
- 180 mg/day
- Population
- Adults
- Participants
- 131
- Ages
- 60+
RCTAcute, dose-dependent cognitive effects of Ginkgo biloba, Panax ginseng and their combination in healthy young volunteers: differential interactions with cognitive demand2002
In healthy young adults, acute ginkgo, ginseng, and their combination produced task-dependent improvements in serial arithmetic performance versus placebo.
- Effect
- Benefit
- Dose
- 320 mg/day
- Population
- Young adults
- Avg age
- ~21
RCTModulation of cognition and mood following administration of single doses of Ginkgo biloba, ginseng, and a ginkgo/ginseng combination to healthy young adults2002n=20
In 20 healthy young adults, single doses of ginkgo 360 mg, ginseng 400 mg, or combined product produced modest acute improvements in some cognitive and mood measures versus placebo.
- Effect
- Benefit
- Dose
- 360 mg/day
- Population
- Young adults
- Participants
- 20
RCTAn examination of the efficacy of Ginkgo biloba extract EGb761 on the neuropsychologic functioning of cognitively intact older adults2000
In 40 cognitively intact adults over 55, ginkgo EGb 761 180 mg/day for 6 weeks did not significantly improve neuropsychological test performance versus placebo.
- Effect
- No Benefit
- Duration
- 6 weeks
- Dose
- 180 mg/day
- Population
- Older adults
- Ages
- 55–86
RCTThe memory enhancing effects of a Ginkgo biloba/Panax ginseng combination in healthy middle-aged volunteers2000
In 256 healthy middle-aged volunteers, a ginkgo (60 mg) plus ginseng (100 mg) combination for 14 weeks significantly improved memory and cognitive test performance versus placebo.
- Effect
- Benefit
- Duration
- 14 weeks
- Dose
- 160 mg 2×/day
- Population
- Adults
GuaranaView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- It is unclear if guarana helps improve thinking or memory.
- Some studies in healthy people show that small doses of guarana extract with caffeine can make people perform certain thinking tasks faster and improve memory for a few hours, but it does not help with reaction time or accuracy.
- Larger doses do not seem to work better.
- A study in young cyclists found that guarana may make reaction time and alertness better than placebo but not better than caffeine.
- Taking guarana regularly for up to five months does not improve brain function in adults.
Browse 12 studies·1 meta-analysis
RCTEffects of Acute Guarana (Paullinia cupana) Ingestion on Mental Performance and Vagal Modulation Compared to a Low Dose of Caffeine2024n=11
In 20 participants, acute guarana (500 mg, 130 mg caffeine) improved cognitive test performance and vagal modulation versus low-dose caffeine or placebo.
- Effect
- No Benefit
- Dose
- 130 mg/day
- Population
- Athletes
- Participants
- 11
- Avg age
- 22.5±4.2
MetaEffect of Guarana (Paullinia cupana) on Cognitive Performance: A Systematic Review and Meta-Analysis2023n=328
A meta-analysis (328 participants) found acute guarana ingestion modestly enhanced attention and memory performance versus control.
- Effect
- Benefit
- Dose
- 500 mg/day
- Participants
- 328
RCTEffects of Dietary Supplementation of a Microalgae Extract Containing Fucoxanthin Combined with Guarana on Cognitive Function and Gaming Performance2023n=61
In 61 healthy adults over 30 days, fucoxanthin-rich microalgae extract plus guarana (500 mg/day) improved cognitive function and gaming performance versus control.
- Effect
- Benefit
- Duration
- 30 days
- Dose
- 500 mg/day
- Population
- Healthy adults
- Participants
- 61
- Avg age
- 22±4
RCTCognitive effects of guarana supplementation with maximal intensity cycling2022n=25
In 25 participants, guarana (125 mg/kg) enhanced post-exercise cognitive performance after maximal cycling versus equivalent caffeine or placebo.
- Effect
- Benefit
- Dose
- 125 mg/kg
- Participants
- 25
RCTThe Effects of Supplementation with a Vitamin and Mineral Complex with Guaraná Prior to Fasted Exercise on Affect, Exertion, Cognitive Performance, and Substrate Metabolism: A Randomized Controlled Trial2015n=45
In 45 active males, a vitamin-mineral complex with guarana (500 mg/day) before fasted exercise improved mood, perceived exertion, and cognition versus control.
- Effect
- Benefit
- Dose
- 500 mg/day
- Population
- Active males
- Participants
- 45
- Avg age
- ~21
RCTHeart rate variability and cognitive function following a multi-vitamin and mineral supplementation with added guarana (Paullinia cupana)2014n=56
In 56 adults (ages 19–45), a multivitamin-mineral supplement with 300 mg guarana improved heart rate variability and cognitive performance versus placebo.
- Effect
- Benefit
- Dose
- 300 mg/day
- Population
- Adults
- Participants
- 56
- Ages
- 19–45
RCTAcute effects of different multivitamin mineral preparations with and without Guaraná on mood, cognitive performance and functional brain activation2013n=20
In 20 adults, multivitamin-mineral preparations with guarana acutely improved mood, cognition, and brain activation on fMRI versus preparations without guarana.
- Effect
- Benefit
- Population
- Healthy adults
- Participants
- 20
- Avg age
- ~29
RCTImproved cognitive performance and mental fatigue following a multi-vitamin and mineral supplement with added guaraná (Paullinia cupana)2008n=129
In 129 young adults (ages 18–24), a vitamin/mineral/guarana supplement improved cognitive performance and reduced mental fatigue versus placebo on demanding tasks.
- Effect
- Benefit
- Population
- Young adults
- Participants
- 129
- Ages
- 18–24
Controlled trialA double-blind, placebo-controlled, multi-dose evaluation of the acute behavioural effects of guaraná in humans2007n=26
In 26 adults, acute guarana doses (37.5–300 mg) improved attention and memory without adverse effects in a double-blind dose-ranging trial.
- Effect
- Benefit
- Dose
- 37.5–300 mg/day
- Population
- Adults
- Participants
- 26
Controlled trialImproved cognitive performance in human volunteers following administration of guarana (Paullinia cupana) extract: comparison and interaction with Panax ginseng2004
In a crossover trial, guarana extract improved cognitive performance, with additional benefit when combined with Panax ginseng versus placebo.
- Effect
- Benefit
- Dose
- 9 mg
RCTThe effects of long-term administration of guarana on the cognition of normal, elderly volunteers1996n=15
In 45 elderly volunteers over long-term follow-up, guarana supplementation did not produce significant cognitive changes versus caffeine or placebo.
- Effect
- No Benefit
- Population
- Older adults
- Participants
- 15
RCTAcute effects of the Paulinia cupana, "Guaraná" on the cognition of normal volunteers1994n=30
In 30 healthy volunteers, acute guarana did not improve cognition, anxiety, or sleep versus caffeine or placebo in a double-blind study.
- Effect
- No Benefit
- Population
- Healthy adults
- Participants
- 30
KavaView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Current research does not show a reliable benefit of kava for cognitive performance.
Browse 13 studies·3 meta-analyses
MetaClinician guidelines for the treatment of psychiatric disorders with nutraceuticals and phytoceuticals: The World Federation of Societies of Biological Psychiatry (WFSBP) and Canadian Network for Mood and Anxiety Treatments (CANMAT) Taskforce2022
WFSBP/CANMAT 2022 guidelines rated acetyl-L-carnitine as not recommended for ADHD based on Grade A evidence from meta-analyses and RCTs.
MetaMedicinal herbs for the treatment of anxiety: A systematic review and network meta-analysis2022
A network meta-analysis of medicinal herbs for anxiety found ginkgo biloba among herbs with significant HAMA score reductions versus placebo, though evidence quality varied.
- Effect
- Benefit
- Population
- Adults
RCTPlant-based Medicines (Phytoceuticals) in the Treatment of Psychiatric Disorders: A Meta-review of Meta-analyses of Randomized Controlled Trials2021n=5,927
A meta-review of 9 phytoceutical meta-analyses (5,927 participants) found supportive evidence for St John's wort, curcumin, and saffron in depression and ginkgo in schizophrenia negative symptoms; kava was not effective for diagnosed anxiety disorders.
- Effect
- No Benefit
- Population
- Adults
- Participants
- 5,927
RCTKava for generalised anxiety disorder: A 16-week double-blind, randomised, placebo-controlled study2020n=171
In 171 adults with generalized anxiety disorder, kava 120 mg kavalactones twice daily for 16 weeks did not reduce anxiety versus placebo and caused more memory problems and liver test abnormalities.
- Effect
- No Benefit
- Duration
- 16 weeks
- Dose
- 120 mg/day
- Population
- Adults
- Participants
- 171
RCTKava in the treatment of generalized anxiety disorder: a double-blind, randomized, placebo-controlled study2013n=75
In 75 adults with generalized anxiety disorder, kava 120–240 mg kavalactones/day for 6 weeks reduced HAMA scores versus placebo (p=0.046) with 26% remission versus 6% on placebo.
- Effect
- Benefit
- Duration
- 6 weeks
- Dose
- 120–240 mg/day
- Population
- Adults
- Participants
- 75
RCTKava in generalized anxiety disorder: three placebo-controlled trials2006n=64
Three pooled placebo-controlled kava trials (64 adults with GAD) found no significant benefit of kava over placebo for anxiety, though kava was well tolerated without hepatotoxicity.
- Effect
- No Benefit
- Population
- Adults
- Participants
- 64
RCTAn internet-based randomized, placebo-controlled trial of kava and valerian for anxiety and insomnia2005n=135
An internet-based RCT (391 adults) found neither kava nor valerian reduced anxiety or insomnia scores more than placebo over 4 weeks.
- Effect
- No Benefit
- Duration
- 8 weeks
- Dose
- 3 g/day
- Population
- Adults
- Participants
- 135
RCTClinical efficacy of kava extract WS 1490 in sleep disturbances associated with anxiety disorders. Results of a multicenter, randomized, placebo-controlled, double-blind clinical trial2004n=61
In 61 adults with sleep disturbance and anxiety, kava WS1490 200 mg/day for 4 weeks improved sleep quality and recuperative effect versus placebo (p=0.007 and p=0.018).
- Effect
- Benefit
- Duration
- 4 weeks
- Dose
- 200 mg/day
- Population
- Patients with anxiety disorders
- Participants
- 61
RCTEnhanced cognitive performance and cheerful mood by standardized extracts of Piper methysticum (Kava-kava)2004
In healthy adults, a single 300 mg kava dose increased state cheerfulness and improved visual attention and short-term memory tasks versus baseline without cognitive impairment.
- Effect
- Benefit
- Dose
- 300 mg/day
- Population
- Healthy adults
RCTKava-Kava administration reduces anxiety in perimenopausal women2003n=19
In perimenopausal women, kava 100–200 mg/day for 3 months reduced anxiety and climacteric symptoms more than calcium alone, with significant anxiety decline versus controls (P<0.009).
- Effect
- Benefit
- Duration
- 3 months
- Dose
- 100 mg/day
- Population
- Women
- Participants
- 19
Clinical trialEffect of kava and valerian on human physiological and psychological responses to mental stress assessed under laboratory conditions2002n=18
In 54 healthy adults, 7 days of kava or valerian reduced systolic blood pressure reactivity to mental stress versus baseline; valerian also lowered heart rate reactivity.
- Effect
- Benefit
- Duration
- 7 days
- Population
- Healthy adults
- Participants
- 18
Clinical trialKava and valerian in the treatment of stress-induced insomnia2001n=24
In 24 adults with stress-induced insomnia, kava 120 mg/day for 6 weeks then valerian 600 mg/day for 6 weeks reduced stress and insomnia with vivid dreams as the commonest valerian side effect.
- Effect
- Benefit
- Duration
- 6 weeks
- Dose
- 120 mg/day
- Population
- Insomnia patients
- Participants
- 24
The correlation between cancer incidence and kava consumption2000
Ecological comparison across Pacific Island nations suggested higher traditional kava consumption correlates with lower age-standardized cancer incidence, though causality was not established.
MultivitaminView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- It’s unclear whether taking multivitamins helps improve memory or thinking. Two studies found that taking specific Swisse multivitamins daily for 16 weeks did not improve memory or reaction time in healthy older adults or young men compared with a placebo. However, a review of several studies found that taking a multivitamin daily for 1 to 12 months slightly improved short‑term memory but not longer‑term memory or verbal skills.
- Findings from studies using other multivitamins are also mixed. In one large study of men aged 65 and older, taking Centrum Silver daily for 12 years did not improve memory or overall thinking. Another large study in adults aged 60 and older found that taking Centrum Silver improved short‑term memory after 1 and 3 years, though it did not help with memory retention or decision‑making. When results from multiple trials were analyzed together, daily multivitamin use for 2–3 years was linked to small improvements in overall thinking and memory, but these changes may not be meaningful in daily life. One related study found that taking a multivitamin for 3 years did not lower the chance of developing mild cognitive impairment or dementia.
- Differences in results may be due to variations in who participated, how long studies lasted, or the specific vitamin formulas used. For example, newer Centrum Silver products include lutein and lycopene, which older versions did not.
Browse 10 studies·2 meta-analyses
MetaEffect of multivitamin-mineral supplementation versus placebo on cognitive function: results from the clinic subcohort of the COcoa Supplement and Multivitamin Outcomes Study (COSMOS) randomized clinical trial and meta-analysis of 3 cognitive studies within COSMOS2024n=2,472
A meta-analysis of 2,472 participants found multivitamin-mineral supplementation produced small but significant improvements in global cognition versus placebo.
- Effect
- Benefit
- Population
- Older adults
- Participants
- 2,472
- Ages
- ≥60
RCTEffects of cocoa extract and a multivitamin on cognitive function: A randomized clinical trial2023n=2,262
In 2,262 older adults over 3 years, 500 mg/day cocoa flavanols did not improve global cognition, while daily multivitamin-mineral supplementation did.
- Effect
- No Benefit
- Duration
- 3 years
- Dose
- 500 mg/day
- Population
- Older adults
- Participants
- 2,262
- Ages
- 18–65
RCTImpact of multivitamin-mineral and cocoa extract on incidence of mild cognitive impairment and dementia: Results from the COcoa Supplement and Multivitamin Outcomes Study for the Mind (COSMOS-Mind)2023n=2,262
The COSMOS-Mind RCT of 2,262 older adults found multivitamin-mineral supplementation over 3 years did not significantly reduce incident mild cognitive impairment.
- Effect
- No Benefit
- Duration
- 3 years
- Population
- Older adults
- Participants
- 2,262
RCTMultivitamin Supplementation Improves Memory in Older Adults: A Randomized Clinical Trial2023n=3,562
A randomized trial of 3,562 older adults (COSMOS-Web) found daily multivitamin supplementation significantly improved memory performance over one year versus placebo.
- Effect
- Benefit
- Population
- Older adults
- Participants
- 3,562
RCTA 1-year randomized controlled trial of a nutritional blend to improve nutritional biomarkers and prevent cognitive decline among community-dwelling older adults: The Nolan Study2022n=305
A 1-year RCT of 305 older adults found a nutritional blend improved nutritional status and some cognitive measures versus control.
- Effect
- No Benefit
- Duration
- 1 year
- Population
- Older adults
- Participants
- 305
- Ages
- 70+
Systematic reviewA Systematic Review of the Effect of Dietary Supplements on Cognitive Performance in Healthy Young Adults and Military Personnel2020
A systematic review found mixed evidence that dietary supplements including multivitamins improve cognitive performance in younger adults.
- Population
- Young adults
- Ages
- 18–35
RCTThe effects of long-chain omega-3 fish oils and multivitamins on cognitive and cardiovascular function: a randomized, controlled clinical trial2015n=160
An RCT of 160 adults aged 50–70 years found multivitamins improved some cognitive measures while omega-3 fish oil improved cardiovascular markers over the study period.
- Effect
- Benefit
- Dose
- 6 g/day
- Population
- Healthy adults
- Participants
- 160
- Ages
- 50–70
RCTEffects of multivitamin, mineral and herbal supplement on cognition in younger adults and the contribution of B group vitamins2014n=138
A 16-week double-blind RCT of 138 adults aged 20–49 found multivitamin/mineral/herbal supplementation improved attention and working memory versus placebo.
- Effect
- Benefit
- Duration
- 16 weeks
- Population
- Adults
- Participants
- 138
- Ages
- 20–49
RCTLong-term multivitamin supplementation and cognitive function in men: a randomized trial2013
A long-term randomized trial in older men found daily multivitamin supplementation modestly improved global cognitive function and slowed cognitive decline.
- Effect
- No Benefit
- Population
- Men
- Avg age
- ~65
MetaThe effects of multivitamins on cognitive performance: a systematic review and meta-analysis2012
A systematic review and meta-analysis found multivitamin supplementation produced small but significant improvements in immediate memory and attention.
TaurineView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Although taurine levels decrease as people age, taking taurine supplements alone does not seem to improve brain health or thinking skills in older adults.
- But drinking energy drinks like Red Bull, which contain taurine along with caffeine and vitamins, may help improve focus, attention, reasoning, driving skills, and reaction time.
- These drinks don’t seem to help with memory.
Browse 10 studies·1 meta-analysis
MetaEffects of taurine supplementation on cognitive function: a systematic review and meta-analysis of randomised controlled trials2025n=402
A meta-analysis of RCTs found taurine supplementation associated with modest cognitive benefits in some populations, though overall evidence quality was low.
- Effect
- No Benefit
- Population
- Adults
- Participants
- 402
RCTEffects of Dietary Taurine-Containing Jelly Supplementation on Academic-Related Characteristics and Academic Achievement in Korean College Entrance Examinees: A Pilot Study2022n=9
In Korean college entrance examinees, taurine-containing jelly supplementation improved some academic-related fatigue and stress measures versus control in this pilot study.
- Effect
- Benefit
- Duration
- 2 weeks
- Dose
- 3 g/day taurine
- Participants
- 9
The Effects of Dietary Taurine-Containing Jelly Supplementation on Cognitive Function and Memory Ability of the Elderly with Subjective Cognitive Decline2022
In elderly adults, dietary taurine jelly supplementation improved some cognitive function and memory scores versus control in this pilot study.
- Effect
- Benefit
- Duration
- 4 weeks
- Dose
- 3 g/day taurine
- Population
- Older adults
- Avg age
- ~72
RCTTaurine supplementation reduces myeloperoxidase and matrix-metalloproteinase-9 levels and improves the effects of exercise in cognition and physical fitness in older women2021n=13
In aged mice and humans, taurine supplementation reduced myeloperoxidase and matrix metalloproteinase-9 and improved tissue inflammation markers versus control.
- Effect
- Benefit
- Duration
- 14 weeks
- Dose
- 1.5 g
- Population
- Women
- Participants
- 13
- Avg age
- ~84
Taurine, caffeine, and energy drinks: Reviewing the risks to the adolescent brain2017
A review summarized evidence on caffeine and taurine in energy drinks, noting performance and safety concerns especially with high intake in adolescents.
- Population
- Men
RCTDifferential cognitive effects of energy drink ingredients: caffeine, taurine, and glucose2012
In healthy adults, caffeine improved cognitive performance while taurine alone did not; combined caffeine-taurine effects varied by outcome in this crossover trial.
- Effect
- No Benefit
- Dose
- 200 mg/day
- Population
- Healthy adults
RCTEffect of caffeine and taurine on simulated laparoscopy performed following sleep deprivation2011n=18
In 18 surgical novices after sleep deprivation, caffeine 150 mg (± taurine) restored laparoscopic simulator speed and economy to rested levels and improved reaction time, though error counts remained elevated versus rested baseline.
- Effect
- Benefit
- Dose
- 150 mg/day
- Population
- Surgical trainees
- Participants
- 18
RCTPositive effects of Red Bull® Energy Drink on driving performance during prolonged driving2011
In sleepy drivers, Red Bull containing caffeine and taurine improved driving performance and reduced lane drifting versus placebo in a simulator study.
- Effect
- Benefit
- Population
- Healthy adults
- Ages
- 21–35
RCTA combination of caffeine and taurine has no effect on short term memory but induces changes in heart rate and mean arterial blood pressure2006
In college students, combined caffeine and taurine from Red Bull altered heart rate variability but did not improve short-term memory versus control ingredients.
- Effect
- No Benefit
RCTAn evaluation of a caffeinated taurine drink on mood, memory and information processing in healthy volunteers without caffeine abstinence2001n=42
In 42 adults with minimal caffeine deprivation, an 80-mg caffeinated taurine drink improved attention and verbal reasoning versus sugar-free and sugar-containing placebos.
- Effect
- Benefit
- Dose
- 80 mg/day
- Population
- Healthy adults
- Participants
- 42
TyrosineView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Taking tyrosine supplements may help improve brain function, especially under stress.
- Small studies show that tyrosine can improve memory, thinking skills, and reaction time in healthy adults exposed to stressful situations like cold, loud noise, or lack of sleep.
- Taking 2 grams of tyrosine might also help improve response speed and focus.
- Some studies used tyrosine along with other amino acids and found improvements in attention and motivation, but it’s not clear if these benefits come from tyrosine alone.
Browse 16 studies
RCTEffects of Five Amino Acids (Serine, Alanine, Glutamate, Aspartate, and Tyrosine) on Mental Health in Healthy Office Workers: A Randomized, Double-Blind, Placebo-Controlled Exploratory Trial2022n=158
An RCT of 42 office workers found that a five-amino-acid blend including tyrosine (SAGAT) for 4 weeks significantly improved motivation and cognitive function after mental work versus placebo.
- Effect
- Benefit
- Duration
- 4 weeks
- Population
- Adults
- Participants
- 158
- Ages
- 20–65
RCTThe catecholamine precursor Tyrosine reduces autonomic arousal and decreases decision thresholds in reinforcement learning and temporal discounting2022n=28
An RCT of 28 healthy men found that a single 2 g tyrosine dose reduced reaction times, lowered decision thresholds, and reduced autonomic arousal during cognitive tasks versus placebo.
- Effect
- Benefit
- Dose
- 2 g
- Population
- Men
- Participants
- 28
Systematic reviewA Systematic Review of the Effect of Dietary Supplements on Cognitive Performance in Healthy Young Adults and Military Personnel2020
A systematic review found mixed evidence that dietary supplements including multivitamins improve cognitive performance in younger adults.
- Population
- Young adults
- Ages
- 18–35
RCTOn the effects of tyrosine supplementation on interference control in a randomized, double-blind placebo-control trial2018n=26
An RCT of 26 adults found tyrosine decreased consciously perceived conflicts in a Simon task but increased subliminally triggered conflicts when concurrent control demands were present.
- Population
- Healthy adults
- Participants
- 26
RCTDose-Dependent Effects of Oral Tyrosine Administration on Plasma Tyrosine Levels and Cognition in Aging2017n=17
An RCT of 17 older adults found dose-dependent increases in plasma tyrosine with oral tyrosine (100–200 mg/kg), associated with dose-dependent declines in working memory performance.
- Effect
- No Benefit
- Dose
- 150 mg/day
- Population
- Older adults
- Participants
- 17
- Ages
- 60–75
RCTEffect of tyrosine ingestion on cognitive and physical performance utilising an intermittent soccer performance test (iSPT) in a warm environment2014
An RCT of 8 soccer players found that 150 mg/kg tyrosine improved vigilance during intermittent exercise in heat but did not improve total distance covered.
- Effect
- No Benefit
- Dose
- 150 mg/kg
- Population
- Athletes
Controlled trialDietary tyrosine benefits cognitive and psychomotor performance during body cooling2007n=15
A controlled study of 15 subjects found that 300 mg/kg tyrosine preserved working memory and marksmanship performance during cold water immersion versus placebo.
- Effect
- Benefit
- Dose
- 300 mg/kg
- Participants
- 15
Controlled trialTyrosine supplementation mitigates working memory decrements during cold exposure2007n=19
A controlled study of 19 volunteers found that 300 mg/kg tyrosine mitigated cold-induced working memory decrements on Match-to-Sample and choice RT tasks versus placebo.
- Effect
- Benefit
- Dose
- 300 mg/kg/day
- Participants
- 19
RCTEffects of tyrosine, phentermine, caffeine D-amphetamine, and placebo on cognitive and motor performance deficits during sleep deprivation2003
A crossover study of sleep-deprived men found that 150 mg/kg tyrosine improved running memory, logical reasoning, tracking, and visual vigilance, though less effectively than D-amphetamine.
- Effect
- Benefit
- Dose
- 150 mg/kg
- Population
- Healthy men
RCTTyrosine improves cognitive performance and reduces blood pressure in cadets after one week of a combat training course1999n=10
An RCT of 21 military cadets found that 2 g/day tyrosine for 5 days during combat training improved memory and tracking performance and reduced systolic blood pressure versus carbohydrate placebo.
- Effect
- Benefit
- Duration
- 5 days
- Dose
- 2 g/day
- Participants
- 10
Clinical trialTyrosine improves working memory in a multitasking environment1999n=10
An RCT of 20 adults found that 150 mg/kg tyrosine significantly enhanced working memory accuracy during a multitasking battery but did not improve performance on simpler tasks.
- Effect
- Benefit
- Dose
- 150 mg/kg
- Population
- Adults
- Participants
- 10
RCTL-tyrosine ameliorates some effects of lower body negative pressure stress1995n=20
An RCT of 20 participants found that 100 mg/kg L-tyrosine increased pulse pressure and P300 amplitude during lower body negative pressure stress versus placebo.
- Effect
- Benefit
- Dose
- 100 mg/kg
- Participants
- 20
RCTThe effects of tyrosine on cognitive performance during extended wakefulness1995
An RCT during 24 h sleep deprivation found that 150 mg/kg tyrosine significantly ameliorated performance decline on a psychomotor task and reduced vigilance lapses for about 3 hours.
- Effect
- Benefit
- Dose
- 150 mg/kg
RCTEffect of tyrosine on cognitive function and blood pressure under stress1994n=16
An RCT of 16 young adults found that 100 mg/kg tyrosine improved performance on two stress-sensitive cognitive tasks and transiently lowered diastolic blood pressure under 90 dB noise stress.
- Effect
- Benefit
- Dose
- 100 mg/kg
- Population
- Young adults
- Participants
- 16
Controlled trialTyrosine reverses a cold-induced working memory deficit in humans1994
A controlled study found that 150 mg/kg tyrosine reversed cold-induced working memory deficits on a delayed matching-to-sample task at 4°C versus placebo.
- Effect
- Benefit
- Dose
- 150 mg/kg
- Population
- Men
Controlled trialTreatment with tyrosine, a neurotransmitter precursor, reduces environmental stress in humans1989
A crossover study found that 100 mg/kg tyrosine significantly reduced symptoms, adverse moods, and performance impairments during 4.5 hours of cold and hypoxia exposure in stress-sensitive subjects.
- Effect
- Benefit
- Dose
- 100 mg/kg
L-CarnitineView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Small, low-quality studies in healthy young adults found that taking L-carnitine for a few days does not improve thinking skills or memory compared to a placebo.
- More research is needed.
Browse 4 studies
MetaL-carnitine for cognitive enhancement in people without cognitive impairment2017n=400
A Cochrane review of 2 RCTs in cognitively healthy young adults found no evidence that L-carnitine improved reaction time, vigilance, or memory after 3 days; overall evidence quality was very low.
- Effect
- No Benefit
- Population
- Healthy adults
- Participants
- 400
RCTL-Carnitine treatment reduces severity of physical and mental fatigue and increases cognitive functions in centenarians: a randomized and controlled clinical trial2007n=34
In 34 centenarians, L-carnitine 2 g/day reduced physical and mental fatigue and improved lipid profiles versus baseline over the treatment period.
- Effect
- Benefit
- Dose
- 2 g/day
- Participants
- 34
RCTThe influence on cognition of the interactions between lecithin, carnitine and carbohydrate2004
In healthy adults, combined lecithin, carnitine, and caffeine for 3 days did not significantly improve cognition versus baseline in a randomized trial.
- Effect
- No Benefit
- Duration
- 3 days
- Dose
- 1.6 g/day
- Population
- Healthy adults
RCTRole of acetyl-L-carnitine in the treatment of cognitive deficit in chronic alcoholism1990n=55
An RCT in 55 abstinent alcoholics found acetyl-L-carnitine 2 g/day for 90 days significantly improved long-term memory and cognitive test performance versus placebo.
- Effect
- Benefit
- Duration
- 90 days
- Dose
- 2 g/day
- Population
- Patients with alcohol dependence
- Participants
- 55
LuteinView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Studies looking at lutein and brain health show mixed results.
- Overall, taking lutein in food or supplements does not seem to clearly improve memory, attention, or other thinking skills.
- In younger adults, a daily supplement of lutein (10 mg) and zeaxanthin (2 mg) for one year showed small improvements in memory.
- Other research suggests that lutein and zeaxanthin may support brain function only when combined with nutrients like choline.
- Differences in dose, length of use, or added nutrients may explain why results are inconsistent.
Browse 3 studies·1 meta-analysis
MetaDietary Lutein and Cognitive Function in Adults: A Meta-Analysis of Randomized Controlled Trials2021
A meta-analysis of lutein RCTs found no significant overall improvement in complex attention, executive function, or memory, though change-from-baseline analyses suggested possible maintenance of executive function.
- Effect
- No Benefit
- Population
- Adults
ObservationalDietary lutein plus zeaxanthin and choline intake is interactively associated with cognitive flexibility in middle-adulthood in adults with overweight and obesity2021n=80
In 80 middle-aged adults with overweight/obesity, higher combined intake of lutein/zeaxanthin and choline was interactively associated with faster cognitive flexibility reaction times.
- Effect
- Benefit
- Population
- Adults
- Participants
- 80
RCTEffects of a Lutein and Zeaxanthin Intervention on Cognitive Function: A Randomized, Double-Masked, Placebo-Controlled Trial of Younger Healthy Adults2017n=37
In 51 younger healthy adults, 12 months of lutein 10 mg plus zeaxanthin 2 mg/day increased macular pigment and improved multiple CNS Vital Signs cognitive domains versus placebo.
- Effect
- Benefit
- Duration
- 12 months
- Dose
- 2 mg/day
- Population
- Healthy adults
- Participants
- 37
- Ages
- 18–30
NattokinaseView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Studies show that eating soy foods or taking soy supplements might help improve memory and thinking, especially in middle-aged and older women after menopause.
Browse 5 studies
ObservationalDietary genistein intake and cognitive performance in a multiethnic cohort of midlife women2006n=380
In 380 SWAN midlife women (ages 42–52), higher genistein intake was associated with better cognitive performance on some tests.
- Effect
- No Benefit
- Population
- Women
- Participants
- 380
- Ages
- 42–52
RCTEffect of soy protein containing isoflavones on cognitive function, bone mineral density, and plasma lipids in postmenopausal women: a randomized controlled trial2004n=175
A 12-month double-blind RCT in 202 postmenopausal women found soy protein with isoflavones did not significantly improve cognition, bone density, or lipids versus placebo.
- Effect
- No Benefit
- Duration
- 12 months
- Population
- Postmenopausal women
- Participants
- 175
- Ages
- 60–75
RCTImproved cognitive function in postmenopausal women after 12 weeks of consumption of a soya extract containing isoflavones2003
A 12-week double-blind RCT in 33 postmenopausal women found 60 mg/day soy isoflavones improved memory and frontal lobe function versus placebo.
- Effect
- Benefit
- Duration
- 12 weeks
- Dose
- 60 mg/day
- Population
- Postmenopausal women
- Ages
- 50–65
RCTIsoflavones and cognitive function in older women: the SOy and Postmenopausal Health In Aging (SOPHIA) Study2003n=27
A 6-month double-blind RCT in postmenopausal women found isoflavone supplementation did not significantly improve cognitive function versus placebo.
- Effect
- No Benefit
- Population
- Postmenopausal women
- Participants
- 27
- Ages
- 55–74
RCTEating soya improves human memory2001
A 10-week RCT in healthy young adults found high-soy diet (100 mg/day isoflavones) improved memory and frontal lobe function versus low-soy diet.
- Effect
- Benefit
- Duration
- 10 weeks
- Dose
- 100 mg/day
- Population
- Healthy adults
American GinsengView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- It is uncertain if American ginseng helps with thinking and memory.
- In healthy young adults, a single dose of 100 to 400 mg of a specific American ginseng extract improved short-term memory and possibly reaction time.
- Taking 200 mg daily for two weeks also improved memory and reduced mental tiredness.
- Products combining American ginseng with bacopa and coffee fruit extract showed small memory and attention benefits shortly after a single dose but did not improve these skills when taken daily for four weeks.
- It is unclear which ingredient caused the effects.
Browse 4 studies
RCTNeurocognitive effects a combined polyphenolic-rich herbal extract in healthy middle-aged adults - a randomised, double-blind, placebo-controlled study2024n=52
In 52 healthy adults aged 35–65, 28 days of a supplement with Bacopa, American ginseng 100 mg, and coffee fruit improved delayed recall and positive affect versus placebo.
- Effect
- Benefit
- Duration
- 28 days
- Dose
- 100 mg/day
- Population
- Healthy adults
- Participants
- 52
- Ages
- 35–65
RCTA randomized, placebo-controlled trial investigating the acute and chronic benefits of American Ginseng (Cereboost®) on mood and cognition in healthy young adults, including in vitro investigation of gut microbiota changes as a possible mechanism of action2022n=61
In 61 young adults, Cereboost American ginseng 200 mg/day improved working memory and attention acutely and after 2 weeks, with gut microbiota shifts toward higher short-chain fatty acid producers in vitro.
- Effect
- Benefit
- Duration
- 2 weeks
- Dose
- 200 mg/day
- Population
- Young adults
- Participants
- 61
RCTAcute effects of combined Bacopa, American ginseng and whole coffee fruit on working memory and cerebral haemodynamic response of the prefrontal cortex: a double-blind, placebo-controlled study2021n=40
In 40 healthy adults, a single dose of Bacopa, American ginseng, and coffee fruit improved N-back accuracy and prefrontal cortex activation versus placebo at 45 minutes.
- Effect
- Benefit
- Population
- Healthy adults
- Participants
- 40
- Ages
- 18–60
RCTEffects of American ginseng (Panax quinquefolius) on neurocognitive function: an acute, randomised, double-blind, placebo-controlled, crossover study2010n=32
In 32 healthy young adults, acute Cereboost American ginseng 100–400 mg improved working memory (Corsi blocks) and calmness at 100 mg without changing blood glucose.
- Effect
- Benefit
- Dose
- 100–400 mg
- Population
- Young adults
- Participants
- 32
- Ages
- 18–40
Green TeaView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- In middle-aged to older healthy adults, taking matcha green tea powder for a few months slightly improved attention and work-related tasks, but did not affect memory or other thinking skills.
- Taking single doses of green tea extract did not improve mood or brain function.
- Drinking combinations with green tea and other plant extracts may help some mental tasks, but it is unclear if green tea alone is responsible.
- More research is needed.
Browse 3 studies
RCTEffects of the active botanical blend "WKUP GT" on attention and cognitive functions after lunch in healthy volunteers2024n=30
In 30 healthy adults in a crossover trial, WKUP GT (carob, guarana, green tea, elderberry) after lunch improved rapid visual information processing and multitasking versus placebo, without raising systolic blood pressure like caffeine.
- Effect
- Benefit
- Population
- Healthy adults
- Participants
- 30
RCTEffects of Daily Matcha and Caffeine Intake on Mild Acute Psychological Stress-Related Cognitive Function in Middle-Aged and Older Adults: A Randomized Placebo-Controlled Study2021n=51
In an RCT of 51 adults (ages 50–69), daily matcha or caffeine intake reduced acute psychological stress responses versus control, with matcha showing additional calming effects.
- Effect
- Benefit
- Population
- Older adults
- Participants
- 51
- Ages
- 50–69
RCTEpigallocatechin gallate, cerebral blood flow parameters, cognitive performance and mood in healthy humans: a double-blind, placebo-controlled, crossover investigation2012n=27
In a crossover RCT of 27 healthy adults, EGCG 135–270 mg improved calmness and reduced mental fatigue during cognitive tasks versus placebo.
- Effect
- No Benefit
- Dose
- 135–270 mg
- Population
- Healthy adults
- Participants
- 27
Lion's Mane MushroomView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Studies on lion's mane mushroom and brain function have had mixed results.
- One study in older adults found no improvement in thinking skills after 12 weeks of taking 3.2 grams daily.
- In younger adults, 28 days of 1.8 grams daily reduced the ability to remember words but did not affect other thinking skills.
- Taking it once improved reaction time but caused more word recall mistakes shortly after.
- Another small study found no effect on thinking or mood after 2 hours.
- These studies were small, so more research is needed to understand if lion's mane really helps cognitive performance.
Browse 3 studies
RCTAcute Effects of Naturally Occurring Guayusa Tea and Nordic Lion's Mane Extracts on Cognitive Performance2023n=40
In 40 adults, a single dose of 650 mg guayusa extract or 1 g Nordic Lion's Mane improved cognition on some neuropsychological tests versus placebo.
- Effect
- Benefit
- Dose
- 650 mg/day
- Population
- Adults
- Participants
- 40
RCTThe Acute and Chronic Effects of Lion's Mane Mushroom Supplementation on Cognitive Function, Stress and Mood in Young Adults: A Double-Blind, Parallel Groups, Pilot Study2023n=41
In 41 healthy young adults, 28 days of 1.8 g/day Lion's Mane showed acute and chronic cognitive and mood benefits versus placebo.
- Effect
- Benefit
- Duration
- 28 days
- Dose
- 1.8 g/day
- Population
- Healthy adults
- Participants
- 41
- Ages
- 18–45
RCTImprovement of cognitive functions by oral intake of Hericium erinaceus2019
In adults taking Hericium erinaceus fruiting body for 12 weeks, MMSE scores improved versus placebo though other cognitive tests showed limited benefit.
- Effect
- Benefit
- Duration
- 12 weeks
- Population
- Adults
Vitamin DView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- It is not clear if vitamin D helps improve thinking and memory.
- People with low vitamin D levels generally exhibit poorer thinking skills and more memory decline.
- But small studies testing vitamin D supplements found no clear improvement in brain function.
- These studies looked at different kinds of people and used various tests, so results are not certain.
Browse 2 studies·2 meta-analyses
MetaA Systematic Review and Meta-Analysis of The Effect of Low Vitamin D on Cognition2017n=19
A meta-analysis of 26 observational and 3 intervention cognition studies found low vitamin D associated with worse cognition, but supplementation showed no significant cognitive benefit.
- Effect
- No Benefit
- Population
- Older adults
- Participants
- 19
MetaVitamin D, cognition, and dementia: a systematic review and meta-analysis2012
A systematic review found lower vitamin D concentrations associated with poorer cognitive performance and higher Alzheimer disease risk in observational studies, with limited RCT evidence.
- Effect
- Benefit
- Population
- Adults
Alpha-Linolenic AcidView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Eating foods rich in alpha-linolenic acid (ALA), like flaxseed oil, might slightly improve some thinking skills in healthy older adults, such as word fluency.
- In healthy adults, consuming an omega-3-rich breakfast bar may help with alertness and memory, but it's unclear if ALA or other ingredients are responsible.
Browse 2 studies
RCTSupplementation with Flaxseed Oil Rich in Alpha-Linolenic Acid Improves Verbal Fluency in Healthy Older Adults2023
12-week RCT in 60 healthy older adults given 2.2 g/day ALA from flaxseed oil found verbal fluency improved versus corn oil placebo; other cognitive tests did not differ.
- Effect
- Benefit
- Duration
- 12 weeks
- Dose
- 2.2 g/day
- Population
- Older adults
- Ages
- 65–80
RCTCognitive and Mood Effects of a Nutrient Enriched Breakfast Bar in Healthy Adults: A Randomised, Double-Blind, Placebo-Controlled, Parallel Groups Study2017n=95
56-day RCT in 95 adults found a nutrient bar with alpha-linolenic acid acutely improved alertness, attention, memory, and executive function versus isocaloric control.
- Effect
- Benefit
- Duration
- 56 days
- Dose
- 21.5 mg/day
- Population
- Healthy adults
- Participants
- 95
- Ages
- 21–40
AvocadoView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Eating an avocado daily for several weeks may improve focused attention in overweight adults, while older adults who regularly eat avocados tend to have better memory and overall brain function.
- Avocados contain nutrients like lutein and healthy fats that may support brain health and cognition.
Browse 2 studies
ObservationalUS Older Adults That Consume Avocado or Guacamole Have Better Cognition Than Non-consumers: National Health and Nutrition Examination Survey 2011-20142021n=2,014
A cross-sectional NHANES analysis of 2,886 adults aged 60+ found avocado or guacamole consumers had significantly better cognitive test scores across multiple measures.
- Effect
- Benefit
- Population
- Older adults
- Participants
- 2,014
- Ages
- 60+
RCTEffects of 12-week avocado consumption on cognitive function among adults with overweight and obesity2020n=47
A 12-week RCT of 84 overweight adults (ages 25–45) found daily Hass avocado improved attentional inhibition and serum lutein, but benefits were independent of lutein changes.
- Effect
- Benefit
- Duration
- 12 weeks
- Population
- Adults
- Participants
- 47
- Ages
- 25–45
ElderberryView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- No summary is available.
Browse 1 study
RCTEffects of the active botanical blend "WKUP GT" on attention and cognitive functions after lunch in healthy volunteers2024n=30
In 30 healthy adults in a crossover trial, WKUP GT (carob, guarana, green tea, elderberry) after lunch improved rapid visual information processing and multitasking versus placebo, without raising systolic blood pressure like caffeine.
- Effect
- Benefit
- Population
- Healthy adults
- Participants
- 30
EleutheroView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Some small studies show that taking eleuthero may slightly improve memory in healthy adults.
- However, it’s not clear if eleuthero alone improves overall thinking or memory in people, and more research is needed.
Browse 2 studies
RCTCombined Treatment with Two Water Extracts of Eleutherococcus senticosus Leaf and Rhizome of Drynaria fortunei Enhances Cognitive Function: A Placebo-Controlled, Randomized, Double-Blind Study in Healthy Adults2020n=31
In 31 healthy adults (40–80 years), combined Eleutherococcus and Drynaria fortunei extracts over 12 weeks significantly improved RBANS figure recall and language domain scores versus placebo, with no adverse events.
- Effect
- Benefit
- Duration
- 12 weeks
- Population
- Healthy adults
- Participants
- 31
- Ages
- 40–80
2-12-24 Russian root (Siberian ginseng) improves cognitive functions in middle-aged people, whereas Ginkgo biloba seems effective only in the elderly1997
A 1997 comparative study reported Siberian ginseng improved cognitive function in middle-aged adults, while Ginkgo biloba benefits were mainly in elderly subjects; detailed outcome data were not available in the indexed abstract.
- Effect
- Benefit
- Population
- Older adults
Flaxseed OilView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- A study in healthy older adults in Japan found that taking 3.7 grams of flaxseed oil daily for 12 weeks helped improve verbal fluency, which is the ability to quickly find and use words.
- This improvement was modest and specific to verbal fluency, as there were no notable changes in other thinking skills like memory or attention.
- Since verbal fluency declines with age and can be a sign of early cognitive decline, flaxseed oil may help support brain function.
Browse 1 study
RCTSupplementation with Flaxseed Oil Rich in Alpha-Linolenic Acid Improves Verbal Fluency in Healthy Older Adults2023
12-week RCT in 60 healthy older adults given 2.2 g/day ALA from flaxseed oil found verbal fluency improved versus corn oil placebo; other cognitive tests did not differ.
- Effect
- Benefit
- Duration
- 12 weeks
- Dose
- 2.2 g/day
- Population
- Older adults
- Ages
- 65–80
HawthornView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- An early study found that taking a combination of D-camphor and hawthorn berry extract (Korodin) was better than placebo for improving thinking speed, attention, and some measures of mental performance in older women.
- It is not clear how much of the effect came from hawthorn itself.
Browse 2 studies
RCTThe effects of repeated administration of camphor-crataegus berry extract combination on blood pressure and on attentional performance - a randomized, placebo-controlled, double-blind study2014n=54
In 54 healthy adults (mean age 24), repeated Korodin (camphor plus crataegus berry extract) increased blood pressure and improved attention versus placebo.
- Effect
- Benefit
- Population
- Healthy adults
- Participants
- 54
- Avg age
- ~24
RCTD-camphor-crataegus berry extract combination increases blood pressure and cognitive functioning in the elderly - a randomized, placebo controlled double blind study2009n=80
In 80 women aged 50–80, Korodin (D-camphor plus crataegus extract) increased blood pressure and improved cognitive processing versus placebo.
- Effect
- Benefit
- Population
- Women
- Participants
- 80
- Ages
- 50–80
Vitamin AView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- It is unclear if taking vitamin A by mouth helps improve thinking skills.
- A large study in children without vitamin A deficiency found that taking high doses of vitamin A twice slightly improved their working memory but it did not improve other thinking skills.
Browse 1 study
RCTEffectiveness of intermittent iron and high-dose vitamin A supplementation on cognitive development of school children in southern Ethiopia: a randomized placebo-controlled trial2024n=504
In 504 Ethiopian schoolchildren, intermittent iron plus high-dose vitamin A for 5 months improved some cognitive test scores versus placebo in this 2×2 factorial RCT.
- Effect
- Benefit
- Duration
- 5 months
- Population
- Children/adolescents
- Participants
- 504
ZeaxanthinView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- It is not clear if taking zeaxanthin by itself improves thinking skills.
- Studies in younger adults show that taking zeaxanthin with lutein for one year can slightly improve some memory skills, like remembering locations.
- Eating choline along with lutein and zeaxanthin is linked to faster thinking on certain tasks, but this benefit doesn’t appear if choline isn’t included.
Browse 2 studies
ObservationalDietary lutein plus zeaxanthin and choline intake is interactively associated with cognitive flexibility in middle-adulthood in adults with overweight and obesity2022n=80
In 80 middle-aged adults with overweight/obesity, higher combined intake of lutein/zeaxanthin and choline was interactively associated with faster cognitive flexibility reaction times.
- Effect
- Benefit
- Population
- Adults
- Participants
- 80
RCTEffects of a Lutein and Zeaxanthin Intervention on Cognitive Function: A Randomized, Double-Masked, Placebo-Controlled Trial of Younger Healthy Adults2017n=37
In 51 younger healthy adults, 12 months of lutein 10 mg plus zeaxanthin 2 mg/day increased macular pigment and improved multiple CNS Vital Signs cognitive domains versus placebo.
- Effect
- Benefit
- Duration
- 12 months
- Dose
- 2 mg/day
- Population
- Healthy adults
- Participants
- 37
- Ages
- 18–30
CaffeineView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Caffeine can have modest but meaningful benefits for certain cognitive functions or cognitive performance.
- It is especially helpful for improving processing speed, attention, and both short- and long-term memory in adults and older people.
- Studies also show caffeine boosts alertness and vigilance, particularly with low to moderate doses around 40 to 300 mg.
- However, caffeine’s effects on more complex thinking skills like judgment and decision-making are less clear and seem to vary.
- Some people may also experience mood changes such as increased anxiety when consuming caffeine.
Browse 1 study
A review of caffeine’s effects on cognitive, physical and occupational performance2016
A review concluded caffeine at ~3–4 mg/kg enhances alertness, reaction time, and physical performance in occupational and athletic settings, with benefits for vigilance and team-sport actions at moderate doses.
- Effect
- Benefit
- Dose
- 0.5 mg/kg
- Population
- Adults
CocoaView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Research on cocoa and brain function gives mixed results.
- A large study in older adults found that taking a cocoa extract with 500 mg of flavanols every day for 3 years did not improve memory or thinking skills.
- Middle‑aged adults who drank a chocolate mix with 250–500 mg of polyphenols in a single dose also showed no improvement.
- Some studies in younger adults show possible benefits.
- Single high doses of cocoa flavanols (around 500–900 mg) have improved reaction time and some thinking skills in tests that required mental effort, but other studies using similar products or lower doses found no effect.
- The differences may depend on how much cocoa is taken, how long it is used, and the type of brain function tests performed.
Browse 9 studies
RCTEffects of cocoa extract and a multivitamin on cognitive function: A randomized clinical trial2023n=2,262
In 2,262 older adults over 3 years, 500 mg/day cocoa flavanols did not improve global cognition, while daily multivitamin-mineral supplementation did.
- Effect
- No Benefit
- Duration
- 3 years
- Dose
- 500 mg/day
- Population
- Older adults
- Participants
- 2,262
- Ages
- 18–65
RCTAcute effects of cocoa flavanols on visual working memory: maintenance and updating2022
In 48 young adults, acute cocoa flavanol doses did not improve visual working memory maintenance or updating versus placebo.
- Effect
- No Benefit
- Dose
- 415 mg/day
- Population
- Young adults
RCTThe effect of acute cocoa flavanol intake on the BOLD response and cognitive function in type 1 diabetes: a randomized, placebo-controlled, double-blinded cross-over pilot study2019n=11
In 11 type 1 diabetes patients, acute 900 mg cocoa flavanols improved flanker task reaction time and brain BOLD responses versus placebo.
- Effect
- Benefit
- Dose
- 900 mg/day
- Population
- Patients with type 1 diabetes
- Participants
- 11
Acute cocoa flavanols intake improves cerebral hemodynamics while maintaining brain activity and cognitive performance in moderate hypoxia2018n=20
In 20 healthy adults under moderate hypoxia, 530 mg cocoa flavanols improved cerebral hemodynamics during some cognitive tasks but did not improve overall cognitive performance.
- Effect
- Benefit
- Dose
- 530 mg/day
- Population
- Healthy adults
- Participants
- 20
- Avg age
- ~23
RCTThe acute effects of cocoa flavanols on temporal and spatial attention2018
In 48 students, acute cocoa flavanols improved visual search efficiency but did not enhance temporal attention or integration versus placebo.
- Effect
- Benefit
- Population
- Pregnant women
- Avg age
- ~22.15
RCTCocoa polyphenols enhance positive mood states but not cognitive performance: a randomized, placebo-controlled trial2013n=72
In 72 healthy middle-aged adults over 30 days, 500 mg/day cocoa polyphenols increased calmness and contentedness versus placebo but did not change cognition.
- Effect
- No Benefit
- Duration
- 30 days
- Dose
- 500 mg/day
- Population
- Healthy adults
- Participants
- 72
RCTConsumption of cocoa flavanols results in acute improvements in mood and cognitive performance during sustained mental effort2010n=30
In 30 healthy adults, acute cocoa flavanol drinks 520–994 mg improved serial subtraction performance and reduced mental fatigue during sustained cognitive demand.
- Effect
- Benefit
- Dose
- 520–994 mg/day
- Population
- Healthy adults
- Participants
- 30
RCTA double-blind, placebo-controlled, randomized trial of the effects of dark chocolate and cocoa on variables associated with neuropsychological functioning and cardiovascular health: clinical findings from a sample of healthy, cognitively intact older adults2008n=101
In 101 healthy older adults over 6 weeks, daily dark chocolate and cocoa did not significantly change neuropsychological performance or cardiovascular measures versus placebo.
- Effect
- No Benefit
- Duration
- 6 weeks
- Dose
- 37 g dark chocolate + 237 mL cocoa beverage/day
- Population
- Older adults
- Participants
- 101
RCTThe effect of flavanol-rich cocoa on the fMRI response to a cognitive task in healthy young people2006n=16
In 16 healthy young adults after 5 days of 150 mg/day cocoa flavanols, fMRI showed increased BOLD response during a cognitive task without faster reaction times.
- Duration
- 5 days
- Dose
- 150 mg/day
- Population
- Young adults
- Participants
- 16
GingerView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- There is not enough evidence to determine if ginger has any benefit for cognitive health.
- More research is needed to know whether ginger really helps with cognitive performance.
Browse 1 study
Zingiber officinale Improves Cognitive Function of the Middle-Aged Healthy Women2011n=60
In 60 healthy middle-aged women, ginger extract 400–800 mg/day for 2 months significantly improved working memory and cognitive test performance versus placebo.
- Effect
- Benefit
- Duration
- 2 months
- Dose
- 400–800 mg
- Population
- Women
- Participants
- 60
- Avg age
- 53.4±3.57
LycopeneView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Studies suggest that people who eat more lycopene-rich foods, like tomatoes, tend to have better thinking and memory skills as they age.
- Some research has found that higher lycopene intake is linked to slower mental decline over time.
- Lycopene’s antioxidant properties may help protect the brain, but more research is needed to prove if it prevents dementia.
Browse 1 study
ObservationalLong-Term Intake of Dietary Carotenoids Is Positively Associated with Late-Life Subjective Cognitive Function in a Prospective Study in US Women2020
A prospective cohort of ~49,000 US women followed up to 28 years found highest vs lowest quintile of total carotenoid intake associated with 33% lower odds of poor subjective cognitive function in later life.
- Effect
- Benefit
- Population
- Women
- Avg age
- ~48
Olive OilView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Some research suggests that middle-aged women with HIV who mainly cook with olive oil have better memory and concentration than those using different oils, but more studies are needed to know for sure.
Browse 1 study
ObservationalOlive Oil Intake Associated with Increased Attention Scores in Women Living with HIV: Findings from the Chicago Women's Interagency HIV Study2019n=166
In 166 women (113 with HIV), higher olive oil use was associated with better attention, verbal learning, and memory scores, with attention gains seen only in women living with HIV.
- Effect
- Benefit
- Population
- Women
- Participants
- 166
Yerba MateView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- It is not clear if drinking yerba mate helps thinking skills.
- A study in healthy young women showed that drinking one serving of yerba mate did not improve alertness, memory, reaction time, or accuracy compared to decaffeinated coffee.
Browse 1 study
Psychological and cardiovascular effects of Guaraná and yerba mate: A comparison with coffee2004
A study of psychological and cardiovascular effects of guaraná and yerba mate; specific cognitive outcome data were unavailable in the abstract.
Algal OilView supplement →
Do not purchase·★★★★★
How we scored this▸
- Most studies show that taking DHA algae oil does not help improve thinking or reading skills in children.
- One study with kids aged 7-12 found no benefit from taking DHA daily for 6 months.
- Some research suggested that higher doses of DHA might help improve reading in some children who find reading difficult, but later studies did not find the same results.
- Overall, DHA supplements don't seem to make kids smarter or improve memory.
Browse 3 studies
RCTNo effect of 6-month supplementation with 300 mg/d docosahexaenoic acid on executive functions among healthy school-aged children: a randomized, double-blind, placebo-controlled trial2021n=94
An RCT in 94 Chinese schoolchildren aged 7–12 found DHA 300 mg/day for 6 months did not improve working memory or cognitive flexibility versus placebo.
- Effect
- No Benefit
- Duration
- 6 months
- Dose
- 300 mg/day
- Population
- Children/adolescents
- Participants
- 94
- Ages
- 7–12
RCTDocosahexaenoic acid for reading, working memory and behavior in UK children aged 7-9: A randomized controlled trial for replication (the DOLAB II study)2018n=84
An RCT in 376 UK children aged 7–9 with reading difficulties found DHA 600 mg/day for 16 weeks did not improve reading, working memory, or behavior versus placebo.
- Effect
- No Benefit
- Duration
- 16 weeks
- Dose
- 600 mg/day
- Population
- Children/adolescents
- Participants
- 84
- Ages
- 7–9
RCTDocosahexaenoic acid for reading, cognition and behavior in children aged 7-9 years: a randomized, controlled trial (the DOLAB Study)2012n=74
A study of 362 children aged 7-9 who were underperforming in reading (<33rd centile) found that 600 mg/day DHA (from algal oil) significantly improved reading and behaviour in 224 children whose initial reading performance was at or below the 20th centile. However this result could not be replicated in a later study.
- Effect
- Benefit
- Dose
- 600 mg/day
- Population
- Children/adolescents
- Participants
- 74
- Ages
- 7–9
Beta-AlanineView supplement →
Do not purchase·★★★★★
How we scored this▸
- Beta-alanine does not reliably improve cognitive performance.
Browse 2 studies
RCTFourteen weeks of β-alanine supplementation and HIIT did not improve serum BDNF concentrations and Stroop test performance2025
In 13 healthy men, 14 weeks of beta-alanine (6.4 g/day) with high-intensity interval training did not improve serum BDNF or Stroop test performance versus placebo, though cardiorespiratory fitness improved with training.
- Effect
- No Benefit
- Duration
- 4 weeks
- Dose
- 6.4 g/day
- Population
- Men
RCTEffects of Four Weeks of Beta-Alanine Supplementation Combined with One Week of Creatine Loading on Physical and Cognitive Performance in Military Personnel2022n=10
A 28-day RCT of 20 military men found adding 7-day creatine loading to 6.4 g/day beta-alanine improved vertical jump, testosterone, physical performance, and cognitive processing versus beta-alanine alone.
- Effect
- No Benefit
- Duration
- 28 days
- Dose
- 6.4 g/day
- Population
- Men
- Participants
- 10
- Avg age
- 21.5±1.5
ResveratrolView supplement →
Do not purchase·★★★★★
How we scored this▸
- One small study in healthy young adults found that taking a supplement with resveratrol and piperine for 28 days did not improve most thinking skills compared to placebo.
Browse 2 studies
RCTThe effects of chronic trans-resveratrol supplementation on aspects of cognitive function, mood, sleep, health and cerebral blood flow in healthy, young humans2015n=60
In 60 healthy adults, 28 days of trans-resveratrol did not significantly improve cognitive performance or cerebral blood flow versus placebo.
- Effect
- No Benefit
- Population
- Healthy adults
- Participants
- 60
- Ages
- 18–30
RCTEffects of resveratrol on cerebral blood flow variables and cognitive performance in humans: a double-blind, placebo-controlled, crossover investigation2010n=9
In 22 healthy adults, single doses of resveratrol 250–500 mg modulated localized cerebral blood flow but did not clearly improve cognitive performance.
- Effect
- No Benefit
- Dose
- 250–500 mg
- Population
- Healthy adults
- Participants
- 9
Saccharomyces boulardiiView supplement →
Do not purchase·★★★★★
How we scored this▸
- It is uncertain if taking Saccharomyces boulardii helps improve thinking or memory.
- In one study, healthy medical students who took 5 billion CFUs daily for a month did not do better on exams or feel less stressed than those taking a placebo.
Browse 1 study
RCTEffect of Supplementation with Saccharomyces Boulardii on Academic Examination Performance and Related Stress in Healthy Medical Students: A Randomized, Double-Blind, Placebo-Controlled Trial2020n=92
In medical students, 30-day S. boulardii supplementation did not significantly improve academic exam performance versus placebo.
- Effect
- No Benefit
- Duration
- 30 days
- Dose
- 40 g/day
- Population
- Pregnant women
- Participants
- 92
- Avg age
- 22.6±1.4
Vitamin B2 (Riboflavin)View supplement →
Do not purchase·★★★★★
How we scored this▸
- It is not clear if taking riboflavin (vitamin B2) alone helps with memory or thinking skills.
- One study in healthy adults aged 40–65 who took a supplement with riboflavin along with other vitamins and herbs for 12 weeks showed no improvement in memory, focus, mood, or stress compared to those who took a placebo.
Browse 1 study
RCTInvestigating the Effects of a Multinutrient Supplement on Cognition, Mood and Biochemical Markers in Middle-Aged Adults with 'Optimal' and 'Sub-Optimal' Diets: A Randomized Double Blind Placebo Controlled Trial2022n=141
A 12-week RCT of 141 middle-aged adults found a multinutrient formula with bacopa raised B vitamin status but did not improve memory overall, though attention improved in those with optimal baseline diets.
- Effect
- No Benefit
- Duration
- 12 weeks
- Population
- Adults
- Participants
- 141
- Ages
- 40–65
YohimbeView supplement →
Do not purchase·★★★★★
How we scored this▸
- Evidence is insufficient for this condition.
Browse 2 studies
RCTEffects of glucocorticoid and noradrenergic activity on spatial learning and spatial memory in healthy young adults2019n=104
A study of 104 healthy young men (mean age 24 years) found that 10 mg yohimbine, 10 mg hydrocortisone, or both before a virtual Morris water maze task did not change spatial learning or memory versus placebo.
- Effect
- No Benefit
- Dose
- 10 mg yohimbine
- Population
- Men
- Participants
- 104
- Avg age
- 24±4
Clinical trialEffects of yohimbine on cerebral blood flow, symptoms, and physiological functions in humans2000n=9
In nine healthy adults, intravenous yohimbine versus placebo reduced whole-brain cerebral blood flow, increased blood pressure and anxiety symptoms, and produced regional cortical CBF increases linked to adrenergic activation.
- Population
- Healthy adults
- Participants
- 9
Evidence visualised
Same ratings as above, aggregated so you can see coverage and imbalance.
| Supplement | DEX | Studies | Meta-analyses | Share |
|---|---|---|---|---|
| Bacopa | ★★★★★56% | 19 | 2 | 11% |
| Tyrosine | ★★★★★56% | 16 | 0 | 9% |
| Ginkgo | ★★★★★56% | 13 | 0 | 7% |
| Kava | ★★★★★56% | 13 | 3 | 7% |
| Guarana | ★★★★★56% | 12 | 1 | 7% |
| Multivitamin | ★★★★★56% | 10 | 2 | 6% |
| Taurine | ★★★★★56% | 10 | 1 | 6% |
| Cocoa | ★★★★★40% | 9 | 0 | 5% |
| Panax Ginseng | ★★★★★68% | 8 | 0 | 5% |
| Theanine | ★★★★★72% | 7 | 1 | 4% |
| Nattokinase | ★★★★★52% | 5 | 0 | 3% |
| American Ginseng | ★★★★★48% | 4 | 0 | 2% |
| L-Carnitine | ★★★★★52% | 4 | 0 | 2% |
| Rhodiola | ★★★★★64% | 4 | 1 | 2% |
| Algal Oil | ★★★★★36% | 3 | 0 | 2% |
| Green Tea | ★★★★★48% | 3 | 0 | 2% |
| Lion's Mane Mushroom | ★★★★★48% | 3 | 0 | 2% |
| Lutein | ★★★★★52% | 3 | 1 | 2% |
| Alpha-Linolenic Acid | ★★★★★44% | 2 | 0 | 1% |
| Avocado | ★★★★★44% | 2 | 0 | 1% |
| Beta-Alanine | ★★★★★32% | 2 | 0 | 1% |
| Eleuthero | ★★★★★44% | 2 | 0 | 1% |
| Hawthorn | ★★★★★44% | 2 | 0 | 1% |
| Resveratrol | ★★★★★32% | 2 | 0 | 1% |
| Vitamin D | ★★★★★48% | 2 | 2 | 1% |
| Yohimbe | ★★★★★32% | 2 | 0 | 1% |
| Zeaxanthin | ★★★★★44% | 2 | 0 | 1% |
| Caffeine | ★★★★★40% | 1 | 0 | <1% |
| Elderberry | ★★★★★44% | 1 | 0 | <1% |
| Flaxseed Oil | ★★★★★44% | 1 | 0 | <1% |
| Ginger | ★★★★★40% | 1 | 0 | <1% |
| Lycopene | ★★★★★40% | 1 | 0 | <1% |
| Olive Oil | ★★★★★40% | 1 | 0 | <1% |
| Saccharomyces boulardii | ★★★★★32% | 1 | 0 | <1% |
| Vitamin A | ★★★★★44% | 1 | 0 | <1% |
| Vitamin B2 (Riboflavin) | ★★★★★32% | 1 | 0 | <1% |
| Yerba Mate | ★★★★★40% | 1 | 0 | <1% |