Cortisol · Evidence-ranked roundup

Best supplements to reduce cortisol, ranked by evidence

Educational guide · By ClearHormones Editorial Team · Updated July 2026

Search "supplements to reduce cortisol" and the results promise a quick fix for a hormone most people have never had measured. This guide takes a calmer, evidence-first approach. First it separates a genuine cortisol disorder — which is a medical diagnosis, not something a capsule treats — from the ordinary, stress-related cortisol that lifestyle and, at the margins, a few supplements may influence. Then it ranks the most-studied options by how strong the evidence actually is. Nothing here is a "cortisol detox," and none of it replaces sleep, movement, or a clinician when symptoms are persistent.

First, which kind of high cortisol?

Before reaching for a supplement, it helps to know what you are treating. A genuine cortisol disorder is a medical diagnosis: Cushing syndrome (too much cortisol) and Addison disease (too little) are identified with specific, validated tests and managed by a clinician — not by an over-the-counter capsule. A 2016 systematic review also found no evidence that "adrenal fatigue" exists as a diagnosis, so an unvalidated at-home cortisol panel is not a reliable basis for self-treatment.

What most people mean by "high cortisol" is different: the ordinary, stress-related rise tied to poor sleep, chronic stress, and a busy nervous system. That is the version lifestyle measures — and, at the margins, a few supplements — may nudge. There is no such thing as a "cortisol detox." If your symptoms are persistent, severe, or unusual, get a proper workup before spending money on pills.

Lifestyle levers come first

The strongest evidence for lowering everyday cortisol is behavioral, not supplemental. Protecting sleep, moving regularly (a 2022 meta-analysis found regular physical activity lowers cortisol and improves sleep), and relaxation practice such as mindfulness (which a meta-analysis of dozens of studies found reduces physiological stress markers) all act on the same stress-regulation pathways with better data than any pill. Treat supplements as a modest add-on to those basics, not a replacement. Our full guide to lowering cortisol ranks the lifestyle levers in detail.

How we ranked these supplements

Each ingredient carries our editorial evidence grade, a synthesis of the human trial data: moderate means fairly consistent small trials with a real but modest effect, and weak means the data are thinner, shorter, or limited to specific situations. Grades rate the studied ingredient and dose, not any brand or product — supplements are unregulated for efficacy, so the label matters less than what was actually tested.

Best-evidenced supplements

These two have the most consistent human trial data for lowering perceived stress and stress-related cortisol. The effects are real but modest, and most trials run only a few weeks to a few months.

  1. #1

    Ashwagandha

    Moderate evidence

    Several small randomized trials suggest standardized ashwagandha root extract reduces perceived stress and morning cortisol over roughly 8 weeks. Trials are short and often industry-funded, rare liver-injury reports exist, and it should not be combined with thyroid medication without medical advice.

    Typical dosing and interactions are in the full review. Read the full Ashwagandha review →

  2. #2

    L-theanine

    Moderate evidence

    L-theanine, an amino acid found in tea, has fairly consistent small-trial evidence for lowering subjective and physiological stress markers without sedation. One four-week randomized trial reported reduced stress symptoms and better sleep. Effect sizes are modest.

    Typical dosing and interactions are in the full review. Read the full L-theanine review →

Weaker or situational evidence

Each of these has some supportive data, but it is thinner, shorter, or limited to specific situations (an acute stressor, or correcting a deficiency). Reasonable to consider with a clinician, with realistic expectations.

  1. #3

    Phosphatidylserine

    Weak evidence

    Small randomized trials suggest phosphatidylserine can blunt the ACTH and cortisol response to acute mental or physical stress at roughly 400-800 mg per day. The trials are small and short, so durability for chronic, everyday stress remains uncertain.

    Typical dosing and interactions are in the full review. Read the full Phosphatidylserine review →

  2. #4

    Magnesium glycinate

    Weak evidence

    A systematic review found magnesium supplementation can modestly reduce subjective anxiety and stress, most clearly in people who are deficient. Direct evidence that it lowers cortisol in already-replete adults is limited; the glycinate form is favored for gastrointestinal tolerability.

    Typical dosing and interactions are in the full review. Read the full Magnesium glycinate review →

  3. #5

    Rhodiola rosea

    Weak evidence

    Rhodiola rosea is an adaptogen with small trials suggesting reduced stress-related fatigue and burnout, but inconsistent effects on cortisol itself. Trial quality is mixed and extract standardization varies, so the evidence is best treated as preliminary.

    Typical dosing and interactions are in the full review. Read the full Rhodiola rosea review →

Supplements do not treat a cortisol disorder

If you have symptoms that point to Cushing syndrome or adrenal insufficiency, or cortisol concerns tied to the menopause transition, that is a conversation for a clinician rather than a supplement aisle. This page is informational and does not recommend a dose or product. For how stress hormones shift in midlife, read cortisol and perimenopause, or browse our menopause telehealth reviews.

Affiliate link Advertiser Disclosure: This site is reader-supported. We may earn an affiliate commission when you sign up for a service through links on our site. This does not influence our editorial recommendations or medical reviews. Read our full disclosure.

Related reading

Frequently asked questions

What is the best supplement to lower cortisol?
Ashwagandha has the most direct human evidence: several small randomized trials report reductions in perceived stress and morning cortisol over roughly 8 weeks. L-theanine is a close second for stress-related cortisol. That said, effects are modest, trials are short, and behavioral levers such as sleep and exercise are better evidenced than any supplement.
Can supplements actually lower cortisol?
Some can modestly, in the context of everyday stress. Small trials suggest ashwagandha, L-theanine, and phosphatidylserine can reduce stress-related cortisol, while magnesium mainly helps when you are deficient and rhodiola shows inconsistent effects on cortisol itself. No supplement treats a diagnosed cortisol disorder, and supplements are not evaluated by the FDA for efficacy.
How do I know if my cortisol is actually high?
There is a difference between ordinary, stress-related cortisol and a genuine disorder. Cushing syndrome (too much cortisol) and Addison disease (too little) are diagnosed with specific validated tests ordered by a clinician. "Adrenal fatigue" is not a recognized medical diagnosis. Persistent or severe symptoms deserve a proper workup rather than an unvalidated at-home panel.
How long do cortisol supplements take to work?
It depends on the goal. Ashwagandha trials typically run about 8 to 12 weeks before measuring stress and cortisol changes, and L-theanine studies span single doses up to several weeks. Phosphatidylserine has mostly been studied for blunting the cortisol spike around an acute stressor. None of this is an overnight "detox," and benefits fade if the underlying stressors are not addressed.
Are cortisol supplements safe, and do they interact with medications?
They are generally well tolerated in trials, but not risk-free. Ashwagandha can overstimulate the thyroid and has rare liver-injury reports; magnesium interacts with certain antibiotics and bone drugs; rhodiola and L-theanine can add to sedatives or blood-pressure medicines. Each linked monograph lists the specific interactions. Tell your clinician and pharmacist what you take, especially in pregnancy or on other medications.

Primary medical sources

  1. PubMedChandrasekhar K et al. "A prospective, randomized double-blind, placebo-controlled study of safety and efficacy of a high-concentration full-spectrum extract of ashwagandha root in reducing stress and anxiety in adults." Indian J Psychol Med 2012;34(3):255-262.
  2. PubMedSalve J et al. "Adaptogenic and anxiolytic effects of ashwagandha root extract in healthy adults: a double-blind, randomized, placebo-controlled clinical study." Cureus 2019;11(12):e6466.
  3. PubMedKimura K et al. "L-theanine reduces psychological and physiological stress responses." Biol Psychol 2007;74(1):39-45.
  4. PubMedHidese S et al. "Effects of L-theanine administration on stress-related symptoms and cognitive functions in healthy adults: a randomized controlled trial." Nutrients 2019;11(10):2362.
  5. PubMedHellhammer J et al. "Effects of soy lecithin phosphatidic acid and phosphatidylserine complex on the endocrine and psychological responses to mental stress." Stress 2004;7(2):119-126.
  6. PubMedStarks MA et al. "The effects of phosphatidylserine on endocrine response to moderate intensity exercise." J Int Soc Sports Nutr 2008;5:11.
  7. PubMedBoyle NB et al. "The effects of magnesium supplementation on subjective anxiety and stress — a systematic review." Nutrients 2017;9(5):429.
  8. PubMedPickering G et al. "Magnesium status and stress: the vicious circle concept revisited." Nutrients 2020;12(12):3672.
  9. PubMedOlsson EM et al. "A randomised, double-blind, placebo-controlled study of the standardised extract SHR-5 of Rhodiola rosea in subjects with stress-related fatigue." Planta Med 2009;75(2):105-112.
  10. PubMedIvanova Stojcheva E, Quintela JC. "The effectiveness of Rhodiola rosea L. preparations in alleviating various aspects of life-stress symptoms and stress-induced conditions." Molecules 2022;27(12):3902.
  11. PubMedCadegiani FA, Kater CE. "Adrenal fatigue does not exist: a systematic review." BMC Endocr Disord 2016;16(1):48.
  12. PubMedDe Nys L et al. "The effects of physical activity on cortisol and sleep: a systematic review and meta-analysis." Psychoneuroendocrinology 2022;143:105843.
  13. PubMedPascoe MC et al. "Mindfulness mediates the physiological markers of stress: a systematic review and meta-analysis." J Psychiatr Res 2017;95:156-178.
  14. NIHNational Institute of Diabetes and Digestive and Kidney Diseases (NIH) — Cushing Syndrome.
  15. NIHNational Institute of Diabetes and Digestive and Kidney Diseases (NIH) — Adrenal Insufficiency & Addison Disease.
  16. FDAFDA. "Dietary Supplements" — supplements are not evaluated by the FDA for efficacy; label claims are not FDA-verified.

ClearHormones publishes editorial health information for education only — not medical advice.