Can supplements help with anxiety, and if so, which ones actually work? The straightforward answer is that the evidence is mixed: a few supplements have modest support from controlled trials, many have little to none, and some carry real risks when combined with prescription medications. Before trying any supplement for anxiety, there are clinical questions worth answering first (questions a proper evaluation can address, and that self-treatment by supplement trial cannot).
The appeal of supplements is understandable: they feel safer than prescription medications, they are widely available without needing to see a prescriber, and the marketing for them often suggests benefits with few downsides. But the research tells a more complicated story, and understanding what the evidence actually shows can help you make a decision grounded in what is known rather than what is claimed.
Which supplements have evidence for anxiety?
A systematic review of nutritional and herbal supplements for anxiety examined the available controlled trials and found that the evidence base is thin for most products (Lakhan & Vieira, 2010). Of the supplements commonly marketed for anxiety, only a handful have been studied rigorously, and even among those, the findings are often modest or inconsistent.
Omega-3 fatty acids have the most consistent evidence. A meta-analysis of 19 clinical trials involving 2,240 participants found that omega-3 supplementation was associated with modest improvement in anxiety symptoms, with an effect size of 0.374 (Su et al., 2018). That effect was stronger in people with diagnosed clinical anxiety disorders than in healthy populations, and higher doses of at least 2,000 milligrams per day produced better results than lower doses. The benefit is real but modest, and it matters most when anxiety is already clinically significant rather than situational.
Magnesium has suggestive but inconclusive evidence for mild anxiety, as covered in detail in the post on magnesium for anxiety. The research shows a possible benefit, particularly for people with low magnesium levels, but the study quality has been poor and the findings inconsistent. It is worth considering as part of a broader approach, but it is not a proven treatment.
L-theanine, an amino acid found in green tea, showed some benefit in reducing stress and anxiety in people exposed to stressful conditions when taken at doses of 200 to 400 milligrams per day, according to a systematic review of controlled trials. The evidence is limited to short-term use and specific contexts, and it has not been tested robustly in people with diagnosed anxiety disorders.
B vitamins were examined in a meta-analysis that found no significant effect on anxiety, though some individual B vitamins showed modest benefits for depressive symptoms when combined with other treatments. For anxiety specifically, the evidence does not support their use as a standalone intervention.
Which supplements have little or no evidence?
Many supplements marketed for anxiety have not been studied rigorously, or the studies that exist are poorly designed and produce inconsistent results. That does not mean they do not work, but it does mean there is no reliable evidence to support using them for anxiety.
Valerian root is often recommended for sleep and anxiety, but the research has been mixed at best. Some small trials have found modest benefits, while others have found none, and a review concluded that the quality of evidence is too low to make a recommendation.
Ashwagandha has been studied in a handful of small trials, some of which reported reductions in stress and anxiety scores, but the trials were short, often poorly controlled, and industry-funded. The evidence is not strong enough to recommend it as a treatment, and more rigorous research is needed.
5-HTP is sometimes used for anxiety because it is a precursor to serotonin, but controlled trials have not demonstrated consistent benefits for anxiety disorders, and it carries risks when combined with antidepressants.
GABA supplements are marketed for anxiety based on the idea that GABA is the brain's main calming neurotransmitter, but oral GABA does not cross the blood-brain barrier effectively, so the biological rationale for its use is weak and the clinical evidence is sparse.
What about supplements that interact with medications?
This is where supplements can become genuinely risky. Some herbal supplements interact with prescription medications in ways that reduce the effectiveness of treatment or create dangerous side effects, and those interactions are not always obvious.
St. John's wort is one of the most studied herbal supplements for mood, but it has not shown benefit for anxiety disorders in controlled trials, and it carries significant drug interaction risks. It induces liver enzymes that metabolize many medications, including birth control pills, blood thinners, immunosuppressants, and some cancer treatments, which can reduce their effectiveness. More importantly, St. John's wort combined with antidepressants can cause serotonin syndrome, a potentially life-threatening condition characterized by confusion, rapid heart rate, high blood pressure, muscle rigidity, and hyperthermia. If you are taking an SSRI or SNRI, St. John's wort should not be started without medical clearance.
Kava has the strongest evidence of any herbal supplement for anxiety, with a Cochrane review finding it more effective than placebo in reducing anxiety scores. However, it has been linked to cases of severe liver toxicity, and multiple countries have restricted or banned its sale. The risk is uncommon, but serious enough that most prescribers will not recommend it, and it should never be combined with alcohol or medications that affect the liver.
Ginkgo biloba, chamomile, and passion flower have modest evidence for anxiety in small trials, but they can also interact with blood thinners, sedatives, and other medications. Those interactions are usually manageable, but they need to be checked before starting rather than discovered after a problem develops.
How do supplements compare to treatments with stronger evidence?
The effect sizes for supplements, even those with the best evidence, are smaller than what has been demonstrated for cognitive behavioral therapy and for medications like selective serotonin reuptake inhibitors, which have been tested in hundreds of controlled trials and shown consistent, replicable benefits across diverse populations.
That does not mean supplements have no role. For someone with mild, situational anxiety who does not meet criteria for a disorder, or for someone who prefers to start with a lower-intensity intervention, a supplement with at least some evidence behind it may be a reasonable first step. But when anxiety is persistent, affecting work or relationships, or interfering with daily functioning, waiting to see whether a supplement helps often means delaying more effective treatment, and that delay has its own cost.
What does a prescriber check before recommending a supplement?
A supplement is not inherently safer than a medication just because it is sold over the counter, and the decision to try one should be made with the same care you would bring to any treatment. A prescriber will typically check several things before recommending a supplement for anxiety.
What else are you taking? Supplements can interact with prescription medications, other supplements, and even some foods. If you are on an SSRI, an anticoagulant, birth control, or medications for blood pressure or diabetes, those interactions need to be reviewed before adding anything new. The assumption that natural products do not interact is wrong, and some of those interactions are serious.
What is your medical history? Supplements can affect the liver, kidneys, blood pressure, and blood sugar, and some carry specific risks for people with certain conditions. If you have kidney disease, liver disease, a bleeding disorder, or poorly controlled diabetes, those conditions change what is safe to try.
What is driving the anxiety? Supplements are sometimes used as a way to avoid addressing what is actually causing or worsening anxiety. If the driver is poor sleep, untreated depression, alcohol use, an undiagnosed medical condition, or ongoing trauma, addressing that underlying issue is usually more effective than adding a supplement. An evaluation clarifies what is going on, and supplements may be part of the plan but rarely the whole answer.
Is the anxiety mild or clinically significant? Mild, situational anxiety may respond to lower-intensity interventions, including supplements, sleep improvement, stress reduction, and lifestyle changes. Moderate to severe anxiety, particularly when it is persistent or interfering with functioning, usually requires more than a supplement, and the evidence-based treatments for those presentations have far stronger support.
How does NCNE approach supplements in psychiatric care?
At NCNE, care is evidence-informed and conservative, which means supplements are considered when the evidence supports them and when they fit the clinical picture, but they are never positioned as a substitute for a thorough evaluation or for treatments with stronger evidence. The practice's approach to holistic psychiatry includes nutritional and supplement support alongside medication, sleep, stress physiology, and lifestyle factors, with everything assessed together rather than in isolation. You can read more about that approach on the holistic psychiatry service page.
Supplements are discussed when appropriate, with attention to what the research actually shows, what interactions need to be checked, and whether a supplement makes sense given what else is going on. No product recommendations or dosing advice are given without a full clinical picture, and supplements are never used to delay an evaluation when anxiety is already affecting daily life.
What should you do if anxiety has been persistent or is affecting your life?
If anxiety has been present for weeks or months, is interfering with work or relationships, is keeping you from doing things you used to do, or is causing physical symptoms like poor sleep or muscle tension, that is a signal it is time for a proper evaluation rather than more self-management. The same is true if you have tried lifestyle changes or supplements and they have not been enough.
A psychiatric evaluation clarifies what is going on: how long symptoms have been present, what might be driving them, what has been tried before, and what treatment options make sense given your history and goals. Where supplements fit, they are discussed. Where medication is appropriate, it is explained plainly and prescribed conservatively. Where something else is the better first step, that is what gets recommended.
Laura Gabriel, PMHNP-BC, is currently accepting new adult clients for psychiatric evaluation and medication management by telehealth in Connecticut, Massachusetts, New Hampshire, Maine, Rhode Island, Virginia, and Kentucky. Initial evaluations are typically $250 to $350 before insurance reimbursement, and follow-up visits are $125 to $200. You can learn more about getting started as a new client or reach out through the contact page; the practice responds within two business days.
References
Lakhan, S. E., & Vieira, K. F. (2010). Nutritional and herbal supplements for anxiety and anxiety-related disorders: systematic review. Nutrition Journal, 9, 42. https://pubmed.ncbi.nlm.nih.gov/20929532/
Sarris, J., Panossian, A., Schweitzer, I., Stough, C., & Scholey, A. (2011). Complementary medicine, exercise, meditation, diet, and lifestyle modification for anxiety disorders: A review of current evidence. Evidence-Based Complementary and Alternative Medicine, 2011, 809653. https://pmc.ncbi.nlm.nih.gov/articles/PMC3434451/
Su, K.-P., Tseng, P.-T., Lin, P.-Y., Okubo, R., Chen, T.-Y., Chen, Y.-W., & Matsuoka, Y. J. (2018). Association of use of omega-3 polyunsaturated fatty acids with changes in severity of anxiety symptoms: A systematic review and meta-analysis. JAMA Network Open, 1(5), e182327. https://pmc.ncbi.nlm.nih.gov/articles/PMC6324500/