Generalised anxiety disorder (GAD)

Overview

Generalised anxiety disorder has three reviewed supplements with low to medium trust. Kava (WA 56; low effect size, very high evidence, medium trust; 12 studies) shows mixed results: a large 16-week trial found no advantage over placebo, and major guidelines recommend against kava for GAD based on the best available research.

Rhodiola (WA 40; low effect size, evidence, and trust) improved symptoms in one small open-label study without placebo control and should be interpreted cautiously. Vitamin D 50,000 IU weekly for three months with usual medications modestly improved anxiety versus medication alone in one small trial. See the heatmap and evidence reviews below for all three entries.

Effect graph

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Relevant supplements

Relevant supplements sorted by DEX Score.


Kava	★★★★★	Low
Vitamin D	★★★★★	Low
Rhodiola	★★★★★	Low

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Studies

Find individual evidence reviews for supplements sorted by DEX Score.

3 supplements for rated at least stars. All purchase bands. No minimum star filter.

KavaView supplement →

Reconsider purchase★★★★★

How we scored this

Effect SizeLowEvidenceVery HighTrustMedium

Evidence Review

Research on kava for generalized anxiety disorder (GAD) shows mixed results.
Some small studies found no benefit compared to placebo, while a few others reported some improvement.
A large, well-conducted study found that taking kava for 16 weeks did not reduce anxiety symptoms better than placebo.
Because of this, major medical guidelines recommend not using kava for treating GAD, either alone or with other treatments, based on the best available research.

Browse 12 studies3 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.

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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

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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.

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RhodiolaView supplement →

Reconsider purchase★★★★★

How we scored this

Effect SizeLowEvidenceLowTrustLow

Evidence Review

It is not clear if rhodiola helps with generalized anxiety disorder (GAD).
One small study gave people with GAD a specific rhodiola extract (170 mg twice daily) for 10 weeks and found that their anxiety and depression symptoms improved compared to the start of the study.
However, since the study did not compare rhodiola with a placebo or other treatment, these results should be interpreted with caution.

Browse 1 study

Clinical trialA pilot study of Rhodiola rosea (Rhodax) for generalized anxiety disorder (GAD)2008n=10

In 10 adults with generalized anxiety disorder, Rhodiola rosea (Rhodax) reduced anxiety scores in this open-label pilot.

Effect: Benefit
Duration: 10 weeks
Dose: 340 mg/day
Population: Adults
Participants: 10
Ages: 34–55

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Vitamin DView supplement →

Reconsider purchase★★★★★

How we scored this

Effect SizeLowEvidenceLowTrustLow

Evidence Review

A small study found that people with generalized anxiety disorder (GAD) who took vitamin D once a week (50,000 IU) for 3 months, in addition to their usual anxiety and depression medicines, had moderate improvements in anxiety compared to those who took only the medicines.

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Vitamin D supplementation ameliorates severity of generalized anxiety disorder (GAD)2019n=15

In 30 adults with generalized anxiety disorder and vitamin D deficiency, 50,000 IU/week vitamin D for 3 months improved GAD-7 scores and raised serotonin versus standard care alone.

Effect: Benefit
Duration: 3 months
Dose: 50000 IU/day
Population: Adults
Participants: 15

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Evidence visualised

Same ratings as above, aggregated so you can see coverage and imbalance.

Purchase-guidance distribution

How many supplements fall in each purchase band

Effect-size distribution

How large the reported benefits tend to be

Study distribution across 3 supplements for generalised anxiety disorder (gad) (14 studies total).
Supplement	DEX	Studies	Meta-analyses	Share
Kava	★★★★★56%	12	3	86%
Rhodiola	★★★★★40%	1	0	7%
Vitamin D	★★★★★40%	1	0	7%

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Generalised anxiety disorder (GAD)

Overview

Effect graph

Relevant supplements

Studies

Evidence visualised

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