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Supplements for Anxiety, Graded: What the Trials Show (Lavender, Ashwagandha, Magnesium and More)

For anxiety, supplements are at best a small add-on to talking therapy or prescribed treatment. Oral lavender oil capsules and ashwagandha have the best trials, with modest drops in anxiety scores (grade B). Saffron eased self-rated anxiety a little (grade B). Kava helped in short trials but failed in a 16-week trial and can injure the liver. St John's wort clashes with many medicines, antidepressants among them.

Published How we grade evidenceEditorial policy

The short version

  • Therapy and prescribed treatment come first: a JAMA review lists talking therapy (CBT) and prescription medicines as the first-line treatments. (Szuhany 2022)
  • Oral lavender oil capsules: lowered anxiety scores in trials. Grade B (Zhang 2022).
  • Ashwagandha: lowered anxiety scores in small trials. Grade B (Fatima 2024).
  • Saffron: eased self-rated anxiety a little; clinician ratings didn't change. Grade B (Mahmoudi 2026).
  • Magnesium, omega-3, probiotics, chamomile: small or inconsistent effects in weaker studies. Grade C (Boyle 2017; Bafkar 2024).
  • Kava: helped in short trials, failed in a 16-week trial in generalized anxiety, and kava products have been linked to rare liver injury. We'd skip it. Grade B (Sarris 2020; NCCIH).

Anxiety disorders are common and treatable. The treatments with the most evidence are cognitive behavioural therapy (CBT), a structured talking therapy, and prescription medicines; a review in JAMA puts both first (Szuhany 2022). This guide covers supplements only, for everyday anxiety or alongside treatment. It gives no advice on prescription medicines: if you take one, every supplement below is a question for your prescriber first.

What is the best supplement for anxiety?

The best-studied options are oral lavender oil and ashwagandha, and their effects are modest. A 2022 network meta-analysis compared 12 herbs across 29 trials in adults with anxiety: oral lavender oil, ashwagandha and ginkgo lowered anxiety scores, kava helped overall but probably not in generalized anxiety disorder, and chamomile, valerian and L-theanine did not clearly beat placebo (Zhang 2022). No supplement has been shown to work as well as CBT.

SupplementWhat trials foundSize of effectGrade
Oral lavender oil capsuleLower anxiety scores than placeboAbout 4 points on a 56-point clinician scaleB
AshwagandhaLower anxiety scores in 5 small trialsAbout 6 points on the same scaleB
SaffronLess self-rated anxiety; no change on clinician ratingsAbout 5 points on a 63-point self-rated scaleB
KavaHelped in short trials; no better than placebo over 16 weeks in generalized anxietyMixedB (we'd skip it)
ChamomileModest help in two small trialsSmallC
MagnesiumPositive in about half of small, poor-quality studiesUnclearC
Omega-3Small effect, mainly at 2 g a day, very low certaintySmallC
ProbioticsSmall to moderate effect, strains varySmallC
L-theanineNo clear effect on anxietyNoneC
B-complex vitaminsNo effect on anxietyNoneB

Does lavender help anxiety?

Grade B for oral lavender oil capsules. In the network meta-analysis, a standardised lavender oil capsule taken by mouth lowered scores on the Hamilton anxiety scale (a 56-point clinician rating) by about 3.8 points more than placebo, and also helped sleep and low mood (Zhang 2022). The US National Center for Complementary and Integrative Health (NCCIH) notes the trials were small and lacked independent funding (NCCIH). Smelling lavender is a different thing: inhaled lavender eased anxiety in short, stressful situations (Donelli 2019). Results for one lavender product don't carry over to teas, oils for the skin or other capsules. See our lavender page.

Does ashwagandha help anxiety?

Grade B. Pooling 5 placebo-controlled trials (254 people), ashwagandha root extract lowered Hamilton anxiety scores by about 6 points, but the trials disagreed widely and were small (Fatima 2024). Our ashwagandha for stress guide covers the doses studied, the forms and how long it takes. It is not for everyone: see the thyroid and liver cautions below.

Does saffron help anxiety?

Grade B, for self-rated anxiety only. A 2026 meta-analysis of 34 trials found that saffron lowered a self-rated anxiety score by about 5 points (6 trials, 339 people) and a self-rated depression score too, but made no difference on clinician-rated anxiety scales (Mahmoudi 2026). The reviewers rated the certainty moderate and asked for better trials with clinician ratings.

Is magnesium good for anxiety?

Grade C. Despite its reputation, the evidence is thin. A systematic review of 18 studies found that half the studies in mildly anxious people (4 of 8) and 4 of 7 in premenstrual syndrome reported a benefit, none after childbirth, and judged the quality of the evidence poor (Boyle 2017). If you take magnesium, the adult upper limit from supplements is 350 mg a day; take more only with blood tests or your clinician's advice (NIH ODS).

Do omega-3, probiotics or chamomile help?

Grade C for each.

  • Omega-3 (fish oil): across 23 trials (2,189 adults), anxiety fell most at 2 g a day, and lower doses did nothing; the authors rated the certainty very low (Bafkar 2024).
  • Probiotics: in 9 trials of people diagnosed with a mental health condition, probiotics lowered anxiety scores, with very mixed results (Asad 2025). A wider review of 29 trials called the effect small and found no agreement on which strain, dose or length works (Zhao 2023).
  • Chamomile: in 57 people with generalized anxiety, chamomile extract for 8 weeks lowered anxiety a little more than placebo (Amsterdam 2009). In a longer trial, 1,500 mg a day kept symptoms lower, but relapses were not significantly fewer (15.2% vs 25.5%) (Mao 2016).

Does L-theanine help anxiety?

Grade C for no clear effect. In a 2026 meta-analysis of 31 trials, a single 200 mg dose sharpened attention, but effects on anxiety were inconsistent and not significant (Gerolymos 2026). In 46 people with generalized anxiety already on an antidepressant, adding 450 to 900 mg a day for 8 weeks did no better than placebo (Sarris 2019). Some AI answers call it "grade A" for anxiety; the trials don't support that. See our theanine page.

Do vitamin D or B vitamins help anxiety?

B vitamins, grade B for no effect: in a meta-analysis of B-complex trials, anxiety did not change (562 people), though stress eased slightly (Young 2019). Vitamin D, grade C: pooled trials found less low mood and anxiety overall, mainly in people with depression or low blood levels, with results that varied hugely between trials (Cheng 2020). Test before you take vitamin D for mood.

Does kava work, and is it safe?

Grade B for short-term relief, and we'd still skip it. A Cochrane review included 11 trials (645 people); in the 6 that could be pooled (345 people), kava extract lowered Hamilton anxiety scores by about 5 points against placebo, in trials of 1 to 24 weeks (Pittler 2003), and a 6-week trial in generalized anxiety looked positive (Sarris 2013). But the largest and longest trial, 171 people with generalized anxiety over 16 weeks, found no benefit; memory problems, tremor and abnormal liver tests were more common on kava (Sarris 2020). Kava products have been linked to rare liver injury, some of it serious or fatal (NCCIH).

What we'd skip

  • Kava. No benefit over 16 weeks in generalized anxiety, and a rare but serious liver risk (Sarris 2020; NCCIH).
  • St John's wort if you take any prescription medicine. It can interact in dangerous, sometimes life-threatening ways, including with antidepressants and birth control pills (NCCIH).
  • Valerian for anxiety. The Cochrane review found a single 36-person trial with no difference from placebo (Miyasaka 2006).
  • Passionflower as a stand-in for treatment. Cochrane found only 2 studies (198 people), too few to judge (Miyasaka 2007).
  • B-complex "stress" vitamins for anxiety. No effect on anxiety in pooled trials (Young 2019).

Safety and interactions

  • With antidepressants or other prescribed medicines: don't add a supplement without asking your prescriber or pharmacist. St John's wort weakens many medicines and, with some antidepressants, can cause serious serotonin side effects (NCCIH). Our pages on St John's wort with SSRIs, ashwagandha with SSRIs and 5-HTP with SSRIs say how well documented each pair is.
  • Ashwagandha: rare liver injury: in a case series of 5 people, jaundice began 2 to 12 weeks after starting, and liver tests returned to normal within 1 to 5 months in the 4 who were followed up (Björnsson 2020). It may raise thyroid hormone levels (Gannon 2014), and NCCIH advises against it with thyroid or autoimmune disease, in pregnancy and while breastfeeding; it may interact with thyroid, diabetes, blood pressure, sedative and seizure medicines (NCCIH; see ashwagandha with levothyroxine).
  • Kava: rare serious liver injury; abnormal liver tests were more frequent on kava than placebo over 16 weeks (Sarris 2020).
  • Chamomile: allergic reactions, including severe ones, are more likely if you are allergic to ragweed, daisies or marigolds (NCCIH).
  • Magnesium: supplement doses above 350 mg a day can cause diarrhoea and cramps; with kidney disease, ask first (NIH ODS). Check your totals with our upper-limit calculator.
  • Lavender, saffron and omega-3: side effects were no more common than on placebo in the pooled trials (Zhang 2022; Bafkar 2024). No interaction studies with antidepressants were found for lavender or saffron.
  • Pregnancy and breastfeeding: ask your doctor or midwife before any of these.

When to see a doctor

  • Right now: if you have thoughts of harming yourself, call or text 988 in the US (the 988 Suicide & Crisis Lifeline) or your local emergency number.
  • Urgently: chest pain, fainting or a racing heart that doesn't settle. These need checking before anyone calls it anxiety.
  • Soon: worry or panic that gets in the way of work, sleep or relationships for more than a few weeks, anxiety with low mood or hopelessness, or using alcohol or other drugs to cope. A clinician can make a diagnosis and offer therapy or medicine.

Don't stop or change a prescribed medicine on your own; ask the prescriber or pharmacist.

FAQ

What is the best supplement for anxiety? Oral lavender oil capsules and ashwagandha have the best trials (grade B), with modest drops in anxiety scores. None has been shown to work as well as talking therapy or prescribed treatment.

Is magnesium good for anxiety? The evidence is thin (grade C): about half of small, poor-quality studies in anxious people found a benefit.

Can I take supplements with my antidepressant? Ask your prescriber or pharmacist first. St John's wort can interact dangerously with antidepressants and many other medicines.

Is kava safe for anxiety? Kava products are tied to rare cases of severe liver damage, and kava did no better than placebo over 16 weeks in generalized anxiety. We'd skip it.

Does L-theanine help anxiety? Not clearly. In trials it sharpened attention, but its effects on anxiety were inconsistent (grade C).

Sources

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  5. Boyle NB, et al. The Effects of Magnesium Supplementation on Subjective Anxiety and Stress-A Systematic Review. Nutrients. 2017. PubMed 28445426 · doi:10.3390/nu9050429
  6. Bafkar N, et al. Efficacy and safety of omega-3 fatty acids supplementation for anxiety symptoms: a systematic review and dose-response meta-analysis of randomized controlled trials. BMC Psychiatry. 2024. PubMed 38890670 · doi:10.1186/s12888-024-05881-2
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