Asthma
Supplements studied for asthma.
Overview
SupplementDEX indexes 22 supplements for asthma across 48 studies.
Vitamin D (WA 68; medium effect size, very high evidence, medium trust) shows mixed results: it may reduce flare-ups in mild asthma but not severe disease, with some trials reporting roughly one-third fewer attacks and others finding no effect. Caffeine (WA 64; medium effect size, medium evidence, high trust) may offer temporary relief for some airway symptoms but does not broadly improve asthma control or quality of life.
Vitamin C (WA 40; very low effect size, high evidence, medium trust), L-Citrulline (WA 44; low effect size, low evidence, medium trust), and Probiotics (WA 44; low effect size, low evidence, medium trust) show no meaningful benefit in available evidence. See the heatmap and evidence reviews below for all indexed supplements.
Effect graph
Relevant supplements
Relevant supplements sorted by DEX Score.
| Vitamin D | ★★★★★ | Medium |
| Caffeine | ★★★★★ | Medium |
| Probiotics | ★★★★★ | Low |
| Lycopene | ★★★★★ | Low |
| L-Citrulline | ★★★★★ | Low |
| L-Carnitine | ★★★★★ | Low |
| Eucalyptus | ★★★★★ | Low |
| Curcumin | ★★★★★ | Low |
| Boswellia | ★★★★★ | Low |
| Zeaxanthin | ★★★★★ | Low |
| Whey Protein | ★★★★★ | Low |
| Vitamin C | ★★★★★ | Very Low / None |
| Vitamin A | ★★★★★ | Low |
| Sulforaphane | ★★★★★ | Low |
| Quercetin | ★★★★★ | Low |
| N-Acetyl Cysteine (NAC) | ★★★★★ | Low |
| Lutein | ★★★★★ | Low |
| Evening Primrose Oil | ★★★★★ | Very Low / None |
| Nattokinase | ★★★★★ | Very Low / None |
| Gamma-Linolenic Acid | ★★★★★ | Very Low / None |
| Borage | ★★★★★ | Very Low / None |
| Astragalus | ★★★★★ | Very Low / None |
Studies
Find individual evidence reviews for supplements sorted by DEX Score.
22 supplements for , and rated at least stars. All purchase bands. No minimum star filter.
Vitamin DView supplement →
Consider purchase·★★★★★
How we scored this▸
- Taking vitamin D might help reduce asthma flare-ups in people with mild asthma but does not seem to help those with severe asthma.
- People with asthma who have low vitamin D tend to have more flare-ups and need more medications, but studies on whether vitamin D supplements help are mixed.
- Some studies show vitamin D lowers asthma attacks by about one-third after a few months to a year, while others show no effect.
- Children with low vitamin D sometimes benefit from supplements, but not always.
- Vitamin D supplements have been tested in many doses and schedules, from daily to monthly high doses.
- Taking vitamin D during pregnancy or early infancy does not prevent children from developing asthma, although higher vitamin D doses in pregnancy may reduce repeated wheezing in babies.
Browse 18 studies·9 meta-analyses
RCTThe effects of prenatal vitamin D supplementation on respiratory and allergy-related outcomes in children: A systematic review and meta-analysis of randomized controlled trials2025
A meta-analysis of 7 RCTs (3,958 mother-infant pairs) found prenatal vitamin D did not reduce childhood RTI, asthma, wheeze, eczema, or allergy.
- Effect
- No Benefit
- Population
- Pregnant women
MetaVitamin D supplementation decrease asthma exacerbations in children: a systematic review and meta-analysis of randomized controlled trials2024n=631
A meta-analysis of 10 RCTs in 1,243 asthmatic children found vitamin D supplementation significantly reduced asthma exacerbations (RR 0.62), especially at recommended daily doses.
- Effect
- Benefit
- Population
- Adults
- Participants
- 631
MetaRelationship between vitamin D and asthma from gestational to adulthood period: a meta-analysis of randomized clinical trials2023
A meta-analysis of 15 RCTs found prenatal vitamin D reduced offspring wheezing 23% but had mixed effects on FEV1 in children and ACT scores in adults with asthma.
- Population
- Women
MetaVitamin D for the management of asthma2023n=766
An updated Cochrane meta-analysis of 20 asthma trials (2,225 participants) found vitamin D reduced severe exacerbations requiring systemic corticosteroids.
- Effect
- Benefit
- Population
- Adults
- Participants
- 766
- Ages
- 5–16
MetaEfficacy of vitamin D supplementation on COPD and asthma control: A systematic review and meta-analysis2022n=3,208
A meta-analysis of 30 COPD/asthma RCTs (3,208 patients) found vitamin D improved some lung function and inflammatory markers but not exacerbations, hospital stay, or mortality.
- Effect
- Benefit
- Population
- COPD and asthma patients
- Participants
- 3,208
MetaVitamin D Supplementation and Allergic Diseases during Childhood: A Systematic Review and Meta-Analysis2022n=2,347
A meta-analysis of 32 RCTs in 2,347 children found vitamin D did not reduce asthma exacerbations overall but cut eczema severity and allergic rhinitis symptoms.
- Effect
- No Benefit
- Population
- Children/adolescents
- Participants
- 2,347
RCTEffect of Vitamin D3 Supplementation on Severe Asthma Exacerbations in Children With Asthma and Low Vitamin D Levels: The VDKA Randomized Clinical Trial2020n=96
In 192 children with asthma and low vitamin D given 4000 IU/day for 48 weeks, supplementation did not improve time to severe exacerbation versus placebo (HR 1.13).
- Effect
- No Benefit
- Duration
- 48 weeks
- Dose
- 4000 IU/day
- Population
- Children/adolescents
- Participants
- 96
- Ages
- 6–16
RCTSix-Year Follow-up of a Trial of Antenatal Vitamin D for Asthma Reduction2020
Six-year VDAART follow-up of 806 mother-infant pairs found prenatal high-dose vitamin D (4400 IU/day) did not reduce asthma or recurrent wheeze at age 6 versus 400 IU/day.
- Effect
- No Benefit
- Dose
- 4400 IU/day
- Population
- Pregnant women
- Ages
- 0–6
RCTHigh-Dose Vitamin D Supplementation During Pregnancy and Asthma in Offspring at the Age of 6 Years2019
Six-year follow-up of a prenatal vitamin D RCT found high-dose versus standard maternal supplementation did not reduce asthma risk in offspring at age 6.
- Effect
- No Benefit
- Population
- Pregnant women
MetaVitamin D supplementation during pregnancy and the risk of wheezing in offspring: a systematic review and dose-response meta-analysis2019n=6,068
A dose-response meta-analysis of 6,068 pregnant women found maternal vitamin D inversely associated with offspring wheezing (pooled OR 0.68), with ~800 IU/day appearing optimal.
- Effect
- Benefit
- Dose
- 800 IU/day
- Population
- Pregnant women
- Participants
- 6,068
MetaPrenatal vitamin D supplementation reduces risk of asthma/recurrent wheeze in early childhood: A combined analysis of two randomized controlled trials2017n=806
Combined analysis of two prenatal RCTs (806+581 women) found high-dose vitamin D reduced offspring asthma/recurrent wheeze to age 3 (aOR 0.74), strongest when maternal 25(OH)D ≥30 ng/mL.
- Effect
- Benefit
- Dose
- 400 IU/day
- Population
- Women
- Participants
- 806
- Ages
- 0–3
Vitamin D and asthma: a case to answer2017
A narrative review discussed mechanistic and clinical evidence suggesting vitamin D may play a role in asthma pathophysiology, calling for further targeted research.
MetaVitamin D supplementation to prevent asthma exacerbations: a systematic review and meta-analysis of individual participant data2017n=1,078
An IPD meta-analysis of 955 asthma patients across 7 RCTs found vitamin D reduced exacerbations requiring systemic corticosteroids (aIRR 0.74), strongest when baseline 25(OH)D <25 nmol/L.
- Effect
- Benefit
- Population
- Asthma patients
- Participants
- 1,078
RCTVitamin D for the management of asthma2016n=658
A Cochrane meta-analysis of 9 asthma trials (680 participants) found vitamin D reduced severe exacerbation rate (RR 0.63) and emergency visits or hospitalizations (OR 0.39).
- Effect
- Benefit
- Population
- Adults
- Participants
- 658
RCTVitamin D Supplementation and the Risk of Colds in Patients with Asthma2016n=203
In 203 adults with asthma given 100,000 IU load plus 4000 IU/day for 28 weeks, vitamin D did not reduce cold severity or frequency; African Americans had higher cold rates.
- Effect
- No Benefit
- Duration
- 28 weeks
- Dose
- 4000 IU/day
- Population
- Adults
- Participants
- 203
RCTDouble-blind randomised placebo-controlled trial of bolus-dose vitamin D3 supplementation in adults with asthma (ViDiAs)2015n=125
In 250 adults with asthma given bolus 3 mg vitamin D3 every 2 months for 1 year, supplementation did not reduce time to exacerbation or upper respiratory infection.
- Effect
- No Benefit
- Duration
- 1 year
- Dose
- 3 mg/2 months
- Population
- Adults
- Participants
- 125
RCTEffect of vitamin D3 on asthma treatment failures in adults with symptomatic asthma and lower vitamin D levels: the VIDA randomized clinical trial2014n=207
The VIDA trial in 408 adults with asthma and vitamin D insufficiency found 100,000 IU load plus 4000 IU/day for 28 weeks did not reduce treatment failure versus placebo.
- Effect
- No Benefit
- Duration
- 28 weeks
- Dose
- 4000 IU/day
- Population
- Adults
- Participants
- 207
RCTSerum vitamin D levels and severe asthma exacerbations in the Childhood Asthma Management Program study2010n=1,024
In 1,024 children with mild-to-moderate asthma followed 4 years, vitamin D insufficiency (≤30 ng/mL) was associated with 50% higher odds of hospitalization or ED visits.
- Effect
- Benefit
- Duration
- 4 years
- Population
- Children/adolescents
- Participants
- 1,024
CaffeineView supplement →
Consider purchase·★★★★★
How we scored this▸
- Caffeine can offer temporary relief for some symptoms of asthma including impaired airway function, but does not improve most symptoms or quality of life.
Browse 1 study
MetaCaffeine for asthma2010
A Cochrane review of 7 crossover trials (75 adults with asthma) found caffeine, even below 5 mg/kg, modestly improved FEV1 for up to 4 hours; people should avoid caffeine for at least 4 hours before lung function testing.
- Effect
- Benefit
- Dose
- 5 mg/kg
- Population
- Adults
BoswelliaView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- It is unclear if taking Boswellia serrata helps with asthma symptoms.
- A small study found that taking Boswellia resin 300 mg three times daily for six weeks improved breathing, reduced asthma attacks, and eased symptoms like shortness of breath in 70% of patients, compared to 27% of those who did not take it.
Browse 1 study
RCTEffects of Boswellia serrata gum resin in patients with bronchial asthma: results of a double-blind, placebo-controlled, 6-week clinical study1998n=40
In 40 patients with bronchial asthma, Boswellia serrata gum resin 300 mg three times daily for 6 weeks improved symptoms and lung function in 70% versus 27% on placebo.
- Effect
- Benefit
- Duration
- 6 weeks
- Dose
- 300 mg 3×/day
- Population
- Women
- Participants
- 40
- Ages
- 18–75
CurcuminView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Small studies have tested turmeric or curcumin added to usual asthma treatment in adults and children.
- These studies found turmeric does not improve lung function or common symptoms like shortness of breath, wheezing, or cough.
- In children, turmeric may help reduce nighttime waking and the need for quick-relief inhalers but does not improve overall asthma symptoms.
- Because studies were small, more research is needed to confirm these results.
Browse 2 studies
RCTCurcuma longa L. ameliorates asthma control in children and adolescents: A randomized, double-blind, controlled trial2019
A study found that curcumin did not reduce symptoms of asthma compared to placebo, however it did lead to less frequent nighttime awakenings, less frequent use of short-acting β-adrenergic agonist inhalers and improved disease control after 3 and 6 months. [10230]
- Effect
- Benefit
- Duration
- 6 months
- Dose
- 30 mg/kg
- Population
- Children/adolescents
RCTEvaluation of Efficacy of Curcumin as an Add-on therapy in Patients of Bronchial Asthma2014n=30
In 60 bronchial asthma patients, 500 mg twice-daily curcumin for 30 days as add-on therapy improved FEV1 and reduced inflammatory markers versus standard care alone.
- Effect
- Benefit
- Duration
- 30 days
- Dose
- 500 mg/day
- Population
- Patients with bronchial asthma
- Participants
- 30
EucalyptusView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- A small study in people with asthma who need steroids showed that taking 200 mg of eucalyptol, a natural compound found in eucalyptus oil, three times a day for 12 weeks helped reduce the dose of steroid medicine by about one third, compared with little change for those taking a placebo.
- This suggests eucalyptol might help some people with asthma reduce their need for steroids.
Browse 1 study
RCTAnti-inflammatory activity of 1.8-cineol (eucalyptol) in bronchial asthma: a double-blind placebo-controlled trial2003
In 32 asthma patients over 12 weeks, 600 mg/day 1,8-cineole (eucalyptol) allowed 36% greater oral prednisolone reduction versus 7% with placebo (P = 0.006), with 12/16 vs 4/16 achieving steroid dose reduction.
- Effect
- Benefit
- Duration
- 12 weeks
- Dose
- 600 mg/day
- Population
- Asthma patients
L-CarnitineView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- There is not enough evidence to determine if L-carnitine has any benefit for asthma.
Browse 1 study
RCTL-carnitine improves the asthma control in children with moderate persistent asthma2012n=50
In 50 children with moderate persistent asthma, L-carnitine for 6 months improved asthma control scores versus baseline alongside standard therapy.
- Effect
- Benefit
- Duration
- 6 months
- Population
- Children/adolescents
- Participants
- 50
- Ages
- 6–12
L-CitrullineView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- There is not enough evidence to determine if L-citrulline has any benefit for asthma.
Browse 1 study
RCTL-Citrulline increases nitric oxide and improves control in obese asthmatics2019n=41
In 41 obese asthmatics, 15 g/day L-citrulline for 2 weeks improved nitric oxide status and asthma control versus baseline in an open-label pilot study.
- Effect
- Benefit
- Duration
- 2 weeks
- Dose
- 15 g/day
- Population
- Adults
- Participants
- 41
LycopeneView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Early research in people with stable asthma found that taking a tomato extract supplement with lycopene (15 mg three times daily) for up to 14 weeks did not reduce asthma attacks compared to a placebo.
- But some studies have found that people who eat more lycopene-rich foods have about a 20% lower chance of having asthma.
- The benefits of lycopene supplements for asthma are still uncertain.
Browse 2 studies
ObservationalAssociation between dietary carotenoid intakes and the risk of asthma in adults: a cross-sectional study of NHANES, 2007-20122022n=1,784
An NHANES cross-section of 13,039 adults found higher total carotenoid intake associated with lower asthma prevalence.
- Effect
- Benefit
- Population
- Adults
- Participants
- 1,784
- Ages
- 20–80
RCTManipulating antioxidant intake in asthma: a randomized controlled trial2012n=137
In 137 asthmatic adults, a high-antioxidant fruit and vegetable diet for 14 days improved lung function and reduced exacerbation risk versus a low-antioxidant diet; lycopene supplements added to the low-antioxidant diet showed no additional benefit.
- Effect
- Benefit
- Duration
- 6 months
- Dose
- 45 mg/day
- Population
- Adults
- Participants
- 137
ProbioticsView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Probiotics have no meaningful benefit for Asthma.
Browse 1 study·1 meta-analysis
RCTEfficacy of probiotics as adjuvant therapy in bronchial asthma: a systematic review and meta-analysis2024n=1,401
A meta-analysis of 12 asthma RCTs (n=1401) found probiotics improved asthma control test scores (OR 1.18, p=0.0001) but not pooled FeNO or eosinophils significantly.
- Effect
- Benefit
- Population
- Asthma patients
- Participants
- 1,401
LuteinView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- People who eat more foods rich in lutein and zeaxanthin may have up to 30% lower chances of having asthma compared to those who eat less.
- It is not yet clear whether lutein alone or lutein supplements provide the same benefit.
Browse 1 study
ObservationalAssociation between dietary carotenoid intakes and the risk of asthma in adults: a cross-sectional study of NHANES, 2007-20122022n=1,784
An NHANES cross-section of 13,039 adults found higher total carotenoid intake associated with lower asthma prevalence.
- Effect
- Benefit
- Population
- Adults
- Participants
- 1,784
- Ages
- 20–80
N-Acetyl Cysteine (NAC)View supplement →
Reconsider purchase·★★★★★
How we scored this▸
- It is uncertain if inhaling N-acetylcysteine (NAC) helps people with asthma.
- One small study found that using NAC as a daily inhaled mist with isoproterenol for a week improved lung function and made mucus less thick compared to placebo.
Browse 2 studies
Effects of N-Acetylcysteine on Asthma Exacerbation2010
A clinical study reported NAC reduced asthma exacerbation frequency, though available evidence is limited and not from large RCTs.
- Effect
- Benefit
Controlled trialA double-blind parallel study of acetylcysteine-isoproterenol and saline-isoproterenol in patients with chronic obstructive lung disease1977
A double-blind study found acetylcysteine-isoproterenol nebulization improved lung function in asthma patients versus saline-isoproterenol control.
- Effect
- Benefit
- Population
- Asthma patients
QuercetinView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- It is not clear if taking quercetin helps with asthma.
- Early research in people with mild to moderate asthma found that taking a quercetin supplement (QFit) at 250 or 500 mg daily for 30 days, along with usual asthma treatment, reduced asthma symptoms during the day and night, improved breathing tests, and lowered the need for rescue inhalers.
- People on usual treatment without quercetin did not have these improvements.
- More research is needed to confirm these benefits.
Browse 1 study
Supplementary prevention and management of asthma with quercetin phytosome: a pilot registry2019
In a pilot registry, quercetin phytosome plus standard asthma care for 30 days improved peak expiratory flow, symptom control, and oxidative stress versus standard care alone.
- Effect
- Benefit
- Duration
- 30 days
- Population
- Healthy adults
SulforaphaneView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- It is unclear if taking sulforaphane helps people with asthma.
- In a small study, taking a broccoli sprout extract supplement for 14 days reduced airway narrowing caused by a test medicine in some people.
- But 20% of participants had worse symptoms, and 20% did not improve.
- Sulforaphane did not improve lung function tests.
Browse 1 study
Clinical trialSulforaphane improves the bronchoprotective response in asthmatics through Nrf2-mediated gene pathways2015n=30
In asthmatics, sulforaphane activated Nrf2 pathways and improved bronchoprotective responses to methacholine versus baseline in this experimental trial.
- Effect
- Benefit
- Duration
- 14 days
- Dose
- 100 μmol/day
- Population
- Asthmatics
- Participants
- 30
- Avg age
- ~38
Vitamin AView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- It is not clear if taking vitamin A by mouth can prevent asthma in children.
- One study found that children who ate more vitamin A at age 7 had better lung function and were less likely to have asthma by ages 11 to 14 compared to children who ate less vitamin A. However, this does not prove that vitamin A prevents asthma.
Browse 1 study
ObservationalDietary intake of vitamin A, lung function and incident asthma in childhood2021
A prospective cohort in the Avon Longitudinal Study found higher preformed vitamin A intake at age 7 was associated with better lung function and lower incident asthma risk at age 15, but not β-carotene.
- Effect
- Benefit
- Dose
- 1 g/day
- Population
- Children/adolescents
- Ages
- 7–15
Vitamin CView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- Even though some people with asthma have lower vitamin C in their blood, consuming more dietary vitamin C or taking supplements does not improve asthma, reduce the use of medication or help you breathe better.
Browse 4 studies·1 meta-analysis
MetaVitamin C for asthma and exercise-induced bronchoconstriction2013n=419
A Cochrane review of 11 asthma trials (419 participants) found insufficient evidence that vitamin C improves asthma exacerbations or quality of life.
- Effect
- No Benefit
- Population
- Adults
- Participants
- 419
MetaObservational studies on the effect of dietary antioxidants on asthma: a meta-analysis2008n=653
A meta-analysis of 10 observational studies (13,653 subjects) found higher dietary vitamin C, E, or beta-carotene intake was not associated with lower asthma risk.
- Effect
- No Benefit
- Participants
- 653
ObservationalLow maternal vitamin E intake during pregnancy is associated with asthma in 5-year-old children2006n=1,861
A cohort of 1,861 children followed to age 5 found higher maternal vitamin E intake during pregnancy associated with lower wheeze and asthma risk.
- Population
- Women
- Participants
- 1,861
- Avg age
- 5
ObservationalSerum vitamin C levels and use of health care resources for wheezing episodes2000n=19
In 19,760 US adults, serum vitamin C level was not associated with wheezing episodes or healthcare use for wheezing after adjustment for confounders.
- Effect
- No Benefit
- Population
- Adults
- Participants
- 19
- Ages
- ≥17
Whey ProteinView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- It is not clear if whey protein helps children with asthma.
- One small study gave children a specific whey protein (20 grams daily) for 30 days but found no improvement in their lung function.
- Since there was no comparison group, more research is needed to know if whey protein is helpful.
Browse 1 study
Clinical trialEffect of whey protein to modulate immune response in children with atopic asthma2006
In a clinical trial in young adults, 10 g 2×/day, for 1 month, although no significant changes in lymphocyte GSH or FEV1 were found for the group as a whole, the two patients with significant increases in lymphocyte GSH concentrations were the only two to demonstrate reductions in methacholine provocation doses (provocative...
- Duration
- 1 month
- Dose
- 10 g 2×/day
- Population
- Young adults
- Avg age
- 12.6±3.6
ZeaxanthinView supplement →
Reconsider purchase·★★★★★
How we scored this▸
- It is not clear if taking zeaxanthin by mouth helps prevent asthma.
- Studies show that people who eat more zeaxanthin and lutein together have up to a 30% lower chance of having asthma compared to those who eat less.
Browse 1 study
ObservationalAssociation between dietary carotenoid intakes and the risk of asthma in adults: a cross-sectional study of NHANES, 2007-20122022n=1,784
An NHANES cross-section of 13,039 adults found higher total carotenoid intake associated with lower asthma prevalence.
- Effect
- Benefit
- Population
- Adults
- Participants
- 1,784
- Ages
- 20–80
Evening Primrose OilView supplement →
Do not purchase·★★★★★
How we scored this▸
- Taking evening primrose oil by mouth does not appear to help treat asthma.
- Several small studies showed that doses of 15–20 mL or 4–6 grams daily for 8 to 16 weeks did not improve asthma symptoms compared with placebo.
Browse 3 studies
RCTEpogam evening primrose oil treatment in atopic dermatitis and asthma1996n=22
A 16-wk study including 22 children with asthma and atopic dermatitis taking topical skin steroids found that evening primrose oil (4-6 grams per day Epogam) had no effect on asthma symptoms compared to placebo. [10714]
- Effect
- No Benefit
- Duration
- 16 weeks
- Dose
- 6 g/day
- Population
- Children/adolescents
- Participants
- 22
RCTA study of evening primrose seed oil in atopic asthma1989
In atopic asthmatics given evening primrose oil (Efamol) for 8 weeks in a double-blind placebo trial, asthma control and histamine challenge tests did not improve despite changes in fatty acid profiles.
- Effect
- No Benefit
- Duration
- 8 weeks
- Population
- Atopic eczema patients
Controlled trialEvening primose oil and fish oil are ineffective as supplementary treatment of bronchial asthma1989
In 29 asthmatics in a crossover trial, 15–20 mL/day evening primrose or fish oil for 10 weeks did not improve peak flow, symptoms, or medication use compared with olive oil placebo.
- Effect
- No Benefit
- Duration
- 10 weeks
- Dose
- 15–20 mL/day
- Population
- Asthmatic patients
AstragalusView supplement →
Do not purchase·★★★★★
How we scored this▸
- Astragalus has mainly been studied as part of herbal mixtures rather than alone.
- A small study in children with mild asthma found no benefit in asthma symptoms or lung function after taking astragalus with other herbs for 6 months.
Browse 1 study
RCTRandomized, double-blind, placebo-controlled trial of herbal therapy for children with asthma2009n=85
In 85 children with mild asthma over 6 months, a herbal formula including astragalus with cordyceps and skullcap did not improve symptoms, lung function, or steroid dose versus vitamins and ATP.
- Effect
- No Benefit
- Duration
- 6 months
- Population
- Children/adolescents
- Participants
- 85
- Ages
- 7–15
BorageView supplement →
Do not purchase·★★★★★
How we scored this▸
- It is unclear if taking borage seed oil helps with asthma symptoms.
- One small study found that taking about 2 grams of borage seed oil daily for one year did not improve symptoms in people with mild to moderate asthma compared to a placebo.
Browse 1 study
RCTSuppression of leukotriene B4 generation by ex-vivo neutrophils isolated from asthma patients on dietary supplementation with gammalinolenic acid-containing borage oil: possible implication in asthma2004
In asthma patients supplemented with 2 g/day GLA-rich borage oil for 12 months, ex vivo neutrophil LTB4 generation was suppressed and DGLA/15-HETrE rose, but asthma clinical scores did not improve significantly.
- Effect
- No Benefit
- Duration
- 12 months
- Dose
- 2.0 g/day
- Population
- Patients with asthma
- Ages
- 16–75
Gamma-Linolenic AcidView supplement →
Do not purchase·★★★★★
How we scored this▸
- GLA has only been studied for asthma when combined with other ingredients, usually fish oil.
- In one small study, a medical drink containing GLA and fish oil for 4 weeks did not improve asthma symptoms or reduce inhaler use compared with a placebo.
- Another small study suggested some improvements in wheezing, quality of life, and inhaler use, but it did not include a proper comparison group and had many dropouts, which makes the results less reliable.
- Overall, there is not enough good evidence to show that GLA helps with asthma.
Browse 1 study
RCTThe impact of a medical food containing gammalinolenic and eicosapentaenoic acids on asthma management and the quality of life of adult asthma patients2008n=65
In an RCT of 35 adults with mild-to-moderate asthma, a medical food with 0.75–1.13 g/day GLA plus EPA did not clearly improve asthma management or quality-of-life scores over 4 weeks versus placebo.
- Effect
- No Benefit
- Duration
- 4 weeks
- Dose
- 1.13 g/day
- Population
- Adults
- Participants
- 65
NattokinaseView supplement →
Do not purchase·★★★★★
How we scored this▸
- Research on soy isoflavones and asthma is limited.
- One study showed that taking soy isoflavone supplements did not improve asthma symptoms or lung function in people with poorly controlled asthma.
- Some earlier studies suggest eating soy foods might be linked to better lung function, but more research is needed.
Browse 2 studies
RCTEffect of a soy isoflavone supplement on lung function and clinical outcomes in patients with poorly controlled asthma: a randomized clinical trial2015n=193
A 24-week multicenter double-blind RCT in 193 adults with poorly controlled asthma found soy isoflavone supplementation did not improve asthma control versus placebo.
- Effect
- No Benefit
- Duration
- 24 weeks
- Population
- Adults
- Participants
- 193
- Avg age
- ~12
ObservationalDietary intake of soy genistein is associated with lung function in patients with asthma2004n=1,033
In 1033 asthma trial participants, higher dietary soy genistein intake was associated with better baseline lung function (FEV1 and peak flow).
- Effect
- Benefit
- Duration
- 2 weeks
- Population
- Patients with asthma
- Participants
- 1,033
- Ages
- 12–75
Evidence visualised
Same ratings as above, aggregated so you can see coverage and imbalance.
| Supplement | DEX | Studies | Meta-analyses | Share |
|---|---|---|---|---|
| Vitamin D | ★★★★★68% | 18 | 9 | 38% |
| Vitamin C | ★★★★★40% | 4 | 1 | 8% |
| Evening Primrose Oil | ★★★★★36% | 3 | 0 | 6% |
| Curcumin | ★★★★★44% | 2 | 0 | 4% |
| Lycopene | ★★★★★44% | 2 | 0 | 4% |
| N-Acetyl Cysteine (NAC) | ★★★★★40% | 2 | 0 | 4% |
| Nattokinase | ★★★★★32% | 2 | 0 | 4% |
| Astragalus | ★★★★★32% | 1 | 0 | 2% |
| Borage | ★★★★★32% | 1 | 0 | 2% |
| Boswellia | ★★★★★44% | 1 | 0 | 2% |
| Caffeine | ★★★★★64% | 1 | 0 | 2% |
| Eucalyptus | ★★★★★44% | 1 | 0 | 2% |
| Gamma-Linolenic Acid | ★★★★★32% | 1 | 0 | 2% |
| L-Carnitine | ★★★★★44% | 1 | 0 | 2% |
| L-Citrulline | ★★★★★44% | 1 | 0 | 2% |
| Lutein | ★★★★★40% | 1 | 0 | 2% |
| Probiotics | ★★★★★44% | 1 | 1 | 2% |
| Quercetin | ★★★★★40% | 1 | 0 | 2% |
| Sulforaphane | ★★★★★40% | 1 | 0 | 2% |
| Vitamin A | ★★★★★40% | 1 | 0 | 2% |
| Whey Protein | ★★★★★40% | 1 | 0 | 2% |
| Zeaxanthin | ★★★★★40% | 1 | 0 | 2% |