Supplements and non-drug measures for depression & anxiety

2 Minutes

Over half of those with depression and/or anxiety self-treat using natural products and supplements.  Reasons include believing that supplements have fewer side effects than antidepressants, prior negative experiences with antidepressants, opting to go the ‘natural’ route and more.

Firstly, those who notice changes in their mood or anxiety levels will usually be advised to try non-drug measures first. What are some examples of this?

  • Maintain social connections with family, friends, colleagues and peers. This may involve joining a support group and speaking with like-minded individuals.
  • Get lots of exercise, which helps to improve mood and wellbeing
  • Reduce stressors in your life, such as ending negative relationships or other commitments
  • Try counselling or cognitive behavioural therapy (CBT), which are considered first in mild to moderate depression and anxiety

When non-drug measures are ineffective, some may opt to try out a supplement before speaking to their doctor about starting on antidepressants. Others might use supplements on top of these non-drug measures. With so many supplements on the market for anxiety and depression, it can be difficult deciding on one that would be of the most benefit for your health. We will delve into some of the most common supplements used to treat anxiety and depression and the evidence behind them.

St John’s Wort

Research shows that St John’s Wort (SJW) can be as effective as certain antidepressants, specifically serotonin specific reuptake inhibitors (SSRIs), in mild to moderate depression.  SJW also has fewer side effects when compared to SSRIs7, which is a major advantage for those struggling with side effects from conventional antidepressants.

It is extremely important that you speak to a healthcare professional and review your medications before starting SJW. There are also a number of drug interactions between SJW and common medications, such as oral contraceptives.

Serious side effects include phototoxicity, mania or hypomania (SJW cannot be taken by those with bipolar disorder) and withdrawal syndromes. Care must be taken to watch out for these side effects. When stopping SJW, make sure to speak to a healthcare professional about slowly tapering down on your dose to prevent withdra

Fish oils (omega-3 fatty acids)

Research shows that omega-3 fatty acids (FAs) may be somewhat effective in those with depression. However, this effect is very small and highly heterogenous, meaning that the benefit derived from omega-3 FAs is not consistent across studies.  In addition, patients on omega-3 FAs did not see any difference in remission rates, improvement in quality of life (QOL) and side effects from treatment.8

Omega-3 FAs contain different ratios of substances called EPA and DHA. Research shows that omega-3 FAs containing at least 60% EPA led to more benefit for those with depression than omega-3 FAs containing less than 60% EPA.  In contrast with the evidence for omega-3 FAs as a whole, omega-3 FAs with higher concentrations of EPA have been shown to consistently benefit those with depression.

Although side effects associated with omega-3 FAs are usually not serious, it’s important to watch out for them and other drug interactions that may arise. Omega-3 FAs are used for a variety of different ailments, so care must be taken to ensure that it is safe and residual effects are minimized.

Kava Kava

Kava Kava is used ceremonially in some cultures for relaxation and the reduction of anxiety. It is unclear how Kava Kava reduces anxiety, but we do know that it works slowly (up to a few months) and is not habit-forming. Research shows that Kava Kava reduces anxiety, but cannot be recommended at this time due to unknowns in dosing, duration and product use.  In addition, Kava Kava cannot be used with other medications and substances that cause depression of the central nervous system (e.g. alcohol), or in those with concurrent liver disease.


L-theanine is used to reduce anxiety related to stress. Research shows that L-theanine may have some benefit in reducing anxiety when taken for four weeks,  but more evidence is needed to ascertain the effectiveness as well as dosing and duration of L-theanine use for anxiety. L-theanine has been found to be safe when used for up to eight weeks, but more evidence is needed for its long-term use.

Anxiety and depression are ailments that can severely impact quality of life, and a number of people use supplements to cope with their symptoms. It’s important to speak with a healthcare professional before starting a supplement, because they can inform you of any potential risks or concerns that they have.


  1. Parikh SV, Quilty LC, Ravitz P, Rosenbluth M,Pavlova B, Grigoriadis S, et al. Canadian Network for Mood and AnxietyTreatments (CANMAT) 2016 Clinical Guidelines for the Management of Adults withMajor Depressive Disorder: Section 2. Psychological Treatments. Can J Psychiatry.2016 Sep;61(9):524–39.
  2. Hidese S,Ogawa S, Ota M, Ishida I, Yasukawa Z, Ozeki M, et al. Effects of L-TheanineAdministration on Stress-Related Symptoms and Cognitive Functions in HealthyAdults: A Randomized Controlled Trial. Nutrients. 2019 Oct 3;11(10):E2362.
  3. Hidese S, Ogawa S, Ota M, Ishida I, YasukawaZ, Ozeki M, et al. Effects of L-Theanine Administration on Stress-RelatedSymptoms and Cognitive Functions in Healthy Adults: A Randomized ControlledTrial. Nutrients. 2019 Oct 3;11(10):E2362.
  4. Frontiers| Pharmacotherapy of Anxiety Disorders: Current and Emerging Treatment Options| Psychiatry [Internet]. [cited 2021 Sep 14]. Available from:
  5. Sublette ME, Ellis SP, Geant AL, Mann JJ.Meta-analysis of the effects of eicosapentaenoic acid (EPA) in clinical trialsin depression. J Clin Psychiatry. 2011 Dec;72(12):1577–84.
  6. Lakhan SE,Vieira KF. Nutritional and herbal supplements for anxiety and anxiety-relateddisorders: systematic review [Internet]. Database of Abstracts of Reviews ofEffects (DARE): Quality-assessed Reviews [Internet]. Centre for Reviews andDissemination (UK); 2010 [cited 2021 Sep 14]. Available from:
  7. Omega-3fatty acids for depression in adults - PubMed [Internet]. [cited 2021 Sep 14].Available from:
  8. Linde K,Berner MM, Kriston L. St John’s wort for major depression. Cochrane Database ofSystematic Reviews [Internet]. 2008 [cited 2021 Sep 14];(4). Available from:
  9. Lu K, GrayMA, Oliver C, Liley DT, Harrison BJ, Bartholomeusz CF, et al. The acute effectsof L-theanine in comparison with alprazolam on anticipatory anxiety in humans.Hum Psychopharmacol. 2004 Oct;19(7):457–65.