1. Home
  2. /
  3. Guides
  4. /
  5. Supplements for Anxiety
Research Guide

Supplements for Anxiety

Anxiety is one of the most common reasons people turn to supplements. We reviewed the clinical evidence for 9 of the most studied to separate what's supported by research from what's driven by marketing.

9 supplements reviewed 22 studies cited Last reviewed: March 2026

Evidence Summary

SupplementEvidenceKey FindingDosage
AshwagandhaStrong4+ meta-analyses: SMD -1.55 to -6.87; dose-response confirmed[1][2]300–600 mg/day
Omega-3 / Fish OilModerate23 RCTs: each 1g/day = SMD -0.70; optimal at 2g/day[5]2 g/day EPA+DHA
KavaModerateNetwork meta-analysis: effective anxiolytic; HAM-A MD = -3.24[7]120–240 mg kavalactones
MagnesiumModerate5/7 studies positive; meta-analysis SMD = 0.16[9][10]300 mg/day
MelatoninModerate*Cochrane: reduces preoperative anxiety (MD = -11.69mm VAS)[13]3–5 mg (pre-procedure)
L-TheanineModerate11 RCTs: reduced psychiatric symptoms more than controls[14]200–400 mg/day
ValerianLimited60 studies: some anxiolytic signal but insufficient per network MA[16]300–600 mg/day
Lion's ManeLimited2 small RCTs: trends toward reduction but not significant[17]1.8–3 g/day
Vitamin B12InsufficientMeta-analysis: no effect on anxiety (SMD = 0.03, p = 0.71)[19]N/A

*Melatonin evidence is strong for preoperative anxiety specifically, but not for chronic/generalized anxiety.

Strong Evidence

Ashwagandha

Ashwagandha has the most robust evidence of any supplement for anxiety. A 2026 dose-response meta-analysis of 22 RCTs found significant anxiety reduction (SMD = -6.87) with a confirmed dose-response relationship.[1] Three additional independent meta-analyses all corroborate these findings.[2][3][4] Cortisol levels were also significantly reduced (MD = -2.58), providing biomarker-level confirmation. No significant safety differences from placebo were found. The most commonly effective dose is 600 mg/day of root extract (KSM-66) for 8+ weeks.

Read our full deep dive: Ashwagandha for Anxiety →

Moderate Evidence

Omega-3 / Fish Oil

A 2024 dose-response meta-analysis of 23 RCTs (2,189 participants) found each 1 g/day of omega-3 produced an anxiety reduction of SMD = -0.70, with optimal benefit at 2 g/day (SMD = -0.93).[5] A 2018 JAMA Network Open meta-analysis confirmed these findings (Hedges g = 0.374, p = 0.01), with greater effects in clinically diagnosed populations and at doses above 2,000 mg/day.[6] EPA appears to be the more active anxiolytic component.

Kava

A network meta-analysis of 29 RCTs across 12 medicinal herbs rated kava as an "effective anxiolytic overall."[7] A separate meta-analysis of 32 trials showed a borderline effect on the Hamilton Anxiety Scale (MD = -3.24, p = 0.059).[8] The caveat: historical concerns about liver toxicity have led to regulatory restrictions in some countries. These appear linked to poor-quality preparations using stem peelings and leaves rather than noble kava root, but the safety debate is ongoing.

Magnesium

A 2024 systematic review found 5 of 7 anxiety studies reported improvement with magnesium, particularly in those with low baseline status.[9] A large meta-analysis showed a small but significant effect (SMD = 0.16, p = 0.03).[10] An RCT of 300 mg/day showed significant anxiety improvement over 8 weeks, with most benefit in the first 4 weeks.[11] Given that ~48% of US adults consume below the EAR for magnesium, correction of subclinical deficiency may explain much of the observed benefit.

Read our full deep dive: Magnesium for Anxiety →

Melatonin (preoperative context)

A Cochrane review of 27 RCTs (2,319 participants) found melatonin "probably reduces preoperative anxiety" with moderate certainty, comparable to midazolam but with fewer cognitive side effects.[13] This is strong Cochrane-level evidence, but specifically for acute preoperative anxiety — not for chronic or generalized anxiety disorders.

L-Theanine

A 2024 systematic review of 11 RCTs found L-theanine reduced psychiatric symptoms more effectively than controls in anxiety disorders, schizophrenia, and ADHD.[14] However, a network meta-analysis found it "did not outperform placebo,"[7] creating conflicting evidence. L-theanine promotes alpha brain waves associated with relaxed alertness and may be most useful for situational stress rather than clinical anxiety.

Limited & Insufficient Evidence

Valerian

While a large review of 60 studies (6,894 participants) found some anxiolytic signal — particularly from whole root preparations — a network meta-analysis found "insufficient evidence to confirm effectiveness" for anxiety specifically.[16] Valerian has a stronger evidence base for sleep than for anxiety.

Lion's Mane

Only 2 small human RCTs exist. A 28-day trial in 41 adults found a trend toward reduced stress (p = 0.051) but not statistical significance.[17] A 4-week trial in 30 women found anxiety "tended to be lower" but again did not reach significance.[18] Promising preclinical data exists, but human evidence remains preliminary.

Vitamin B12

A meta-analysis of 18 articles (2,015 participants) found no effect of B vitamins on anxiety (SMD = 0.03, p = 0.71).[19] B vitamins may help with stress perception (p = 0.03) but not clinical anxiety. Despite popular belief, B12 supplementation does not appear to meaningfully reduce anxiety.

What to Consider

Frequently Asked Questions

What supplement has the strongest evidence for anxiety?

Ashwagandha, by a significant margin. Four independent meta-analyses show consistent, significant anxiety reductions with effect sizes substantially larger than any other supplement. The optimal dose appears to be 600 mg/day of root extract for 8+ weeks. See our full analysis →

Does magnesium help with anxiety?

The evidence is moderate. A systematic review found 5 of 7 studies reported improvement, and a meta-analysis showed a small but significant effect. Benefits appear strongest in those with low magnesium status — which affects roughly 48% of US adults. See our full analysis →

Is omega-3 good for anxiety?

A dose-response meta-analysis of 23 RCTs found a meaningful anxiolytic effect, peaking at 2 g/day. Effects were stronger in clinically diagnosed populations. EPA appears to be the more active component. It's among the better-supported supplements for anxiety, though the evidence is not as strong as for ashwagandha.

Medical Disclaimer: This guide is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare provider before starting any supplement regimen. SafeSupps does not recommend specific supplements — we present the research so you can make informed decisions.

References

  1. Alsanie SA, et al. "Effects of ashwagandha on mental health in adults: dose-response meta-analysis of 22 RCTs." Complement Ther Med. 2026. PubMed
  2. Akhgarjand C, et al. "Ashwagandha supplementation for anxiety and stress." Phytother Res. 2022;36(11):4115-4124. PubMed
  3. Marchi M, et al. "Ashwagandha for mental health symptoms." BJPsych Open. 2025. PubMed
  4. Arumugam V, et al. "Ashwagandha on stress and anxiety: meta-analysis." Explore (NY). 2024. PubMed
  5. Bafkar et al. "Omega-3 dose-response meta-analysis for anxiety." BMC Psychiatry. 2024. 23 RCTs, 2,189 participants. PubMed
  6. Su KP, et al. "Association of omega-3 polyunsaturated fatty acids with anxiety symptoms." JAMA Netw Open. 2018;1(5):e182327. PubMed
  7. Zhang W, et al. "Network meta-analysis of medicinal herbs for anxiety." Pharmacol Res. 2022. 29 RCTs, 12 herbs. PubMed
  8. Baric H, et al. "Complementary and alternative medicine for GAD." Adv Ther. 2018. 32 trials. PubMed
  9. Rawji A, et al. "Supplemental Magnesium on Anxiety and Sleep Quality." Cureus. 2024;16(4):e59317. PubMed
  10. Wang H, et al. "Antioxidant supplementation for depression and anxiety." J Affect Disord. 2023. 52 studies, 4,049 participants. PubMed
  11. Noah L, et al. "Magnesium and B6 on mental health in stressed adults." Stress Health. 2021;37(5):1010-1023. PubMed
  12. Botturi A, et al. "Magnesium in Mental Disorders." Nutrients. 2020;12(6):1661. PubMed
  13. Madsen BK, et al. "Melatonin for preoperative anxiety." Cochrane Database Syst Rev. 2020. 27 RCTs, 2,319 participants. PubMed
  14. Moshfeghinia R, et al. "L-Theanine on psychiatric symptoms." BMC Psychiatry. 2024. 11 RCTs. PubMed
  15. Lakhan SE, Vieira KF. "Nutritional and herbal supplements for anxiety." Nutr J. 2010. 24 studies, 2,619 participants. PubMed
  16. Shinjyo N, et al. "Valerian Root for Sleep and Associated Disorders." J Evid Based Integr Med. 2020. 60 studies. PubMed
  17. Docherty S, et al. "Lion's Mane in healthy adults." Nutrients. 2023. RCT, 41 participants. PubMed
  18. Nagano M, et al. "Hericium erinaceus on depression and anxiety." Biomed Res. 2010. RCT, 30 females. PubMed
  19. Young LM, et al. "B vitamin supplementation on mood and anxiety." Nutrients. 2019. 18 articles, 2,015 participants. PubMed

Related Guides

Research GuideSupplements for Sleep Research GuideSupplements for Energy ComparisonAshwagandha vs Magnesium for Anxiety