Does Ashwagandha Lower Cortisol? What the Trials Show
Quick answer: Yes, in trials. Standardized ashwagandha root extract lowered cortisol compared with placebo in several randomized trials. One 60-day trial in 64 stressed adults found blood cortisol about 28% lower.
The trials in this article used 225 to 600 mg of extract a day for 30 to 90 days. The studies are small, short and mostly from India. Long-term safety is unknown, and a 2026 case report links 950 mg a day for over a year to a suppressed stress-hormone system.
Skip it if you're pregnant, breastfeeding, or have thyroid, liver or autoimmune conditions, or if you take sedatives or thyroid, diabetes, blood pressure or immunosuppressant medication. Talk to a doctor or pharmacist first.
Table of contents
- What cortisol does and why lower isn't always better
- Does ashwagandha lower cortisol? What the trials found
- How to read a cortisol result
- How long to take ashwagandha to lower cortisol
- Ashwagandha cortisol dosage and best time to take
- Does ashwagandha reduce belly fat?
- Why don't doctors recommend ashwagandha?
- Downsides and side effects
- Run the 8-point safety check
- How to choose an ashwagandha supplement
- Other ways to lower cortisol
- Questions to bring to your doctor
- Frequently asked questions
One number drives most of the ashwagandha cortisol story: 28%.
A 2012 trial gave 64 chronically stressed adults in India either ashwagandha root extract or placebo for 60 days. Blood cortisol fell about 28% in the ashwagandha group and about 8% in the placebo group.
The number is real. It comes from one extract, one center and 64 people.
A 2026 meta-analysis of 23 trials backs a cortisol drop. A 2026 case report describes the opposite problem, a stress-hormone system pushed too low. Both sit in the evidence, and you need both to decide whether ashwagandha fits your situation.
What cortisol does and why lower isn't always better
Cortisol is a hormone made by your adrenal glands. The hypothalamic-pituitary-adrenal (HPA) axis, a signaling system linking your brain and adrenal glands, regulates its release. During stress this system raises cortisol, which helps you respond in the short term.
Some people stay high for too long. Healthline's 2026 review links long-term high cortisol with high blood pressure, heart disease, type 2 diabetes, weight gain, poor sleep and trouble concentrating.
Cortisol also follows a daily rhythm. It peaks in the morning and falls through the day, so the time of a test matters.
Too little cortisol is a medical problem as well. Adrenal insufficiency, including Addison disease, needs treatment. The goal is a normal level, not the lowest one.
Does ashwagandha lower cortisol? What the trials found
In most randomized trials, yes. The NIH Office of Dietary Supplements reviewed a 2021 analysis of 7 studies with 491 adults, all from India. People took ashwagandha or placebo for 6 to 8 weeks at 240 to 1,250 mg a day of extract. The ashwagandha groups reported less stress, anxiety, sleeplessness and fatigue, and had lower serum cortisol than the placebo groups.
The table below, built from the NIH fact sheet and published trial reports, compares five trials reporting cortisol and one trial measuring perceived stress and fatigue. Together they show why a change in cortisol and a change in how people feel need separate checks.
| Trial | People | Dose and length | What was measured | Result | Limit |
|---|---|---|---|---|---|
| Chandrasekhar, 2012 | 64 adults with chronic stress | 300 mg twice a day for 60 days | Serum (blood) cortisol | About 28% lower, against about 8% on placebo | One extract, one center |
| Dose trial, 2019 | 60 adults | 250 or 600 mg a day for 8 weeks | Cortisol | Lower in the ashwagandha groups, no change in controls | 60 people, 8 weeks |
| Lopresti, 2019 | 60 adults with stress | 240 mg a day for 60 days | Morning cortisol | Lower than placebo | One branded extract |
| Florida trial, 2022 | 60 adults with stress | 225 or 400 mg a day for 30 days | Saliva cortisol | Lower than placebo at 225 mg | Only 30 days, one dose showed it |
| Prolanza trial, 2021 | 130 healthy adults with stress | One 300 mg sustained-release capsule a day for 90 days | Serum cortisol | Lower than placebo, with better stress and sleep scores | Two centers in India |
| Witholytin trial, 2023 | 120 overweight adults with fatigue | 200 mg twice a day for 12 weeks | Perceived stress, fatigue | No drop in perceived stress, less fatigue | NIH summary does not report cortisol |
A 2026 meta-analysis in Planta Medica pooled 23 randomized trials with 1,706 people. Ashwagandha lowered cortisol compared with placebo. It also raised serotonin, and raised testosterone in men but not in women. Subgroup analyses suggested a dose-response pattern tied to withanolide content.
The authors report heterogeneity between trials and limited data for some hormones, and they call for more standardized trials. Read the pooled result as a pattern across studies. It predicts little about any one person or product.
Averages hide a lot. The trials used different extracts, doses and populations, and several tested branded products. The NIH fact sheet says this variety makes it difficult to name one extract or one recommended amount.
For sleep, anxiety and the other reported benefits, see our guide to what the ashwagandha research shows.
Evidence snapshot
- Cortisol drops against placebo in most trials and in a 2026 meta-analysis.
- The trials are small, run 30 to 90 days, and come mostly from India.
- Effects beyond about 3 months, and the right dose for any one person, are unknown.
How to read a cortisol result
A headline saying "lowers cortisol" hides three different measurements.
Serum cortisol comes from a blood draw. It captures one moment, and cortisol changes through the day.
Saliva cortisol comes from a spit sample. It's easier to collect, so researchers test more often. The Florida trial used it.
Stress questionnaires, such as the Perceived Stress Scale, measure how you feel. They say nothing about your hormone levels.
Ask five questions about any ashwagandha headline, including the ones on this page:
- How many people took part, and where did they live?
- Which extract did they take, and at what daily dose?
- How long did the trial run?
- Was cortisol measured in blood or saliva, and at what time of day?
- Who paid for the study? Read the funding and conflict-of-interest statements.
How long to take ashwagandha to lower cortisol
Trials ran 30 to 90 days. In the Florida trial, saliva cortisol was lower after 30 days at 225 mg a day. Chandrasekhar's blood results came after 60 days. The 130-person Prolanza trial ran 90 days and reported lower serum cortisol with better stress and sleep scores.
The 8-week mark shows up most often. A 2021 meta-analysis on sleep found larger benefits when treatment lasted at least 8 weeks.
The trials above ran 30 to 90 days, and a 24-week weight trial ran longer. None establishes safety over many months or years. NIH says ashwagandha appears well tolerated for up to about 3 months, and its long-term safety is not known. The 2026 case report described below found a stress-hormone system still suppressed at follow-up.
Online advice about cycling, such as 2 months on and 1 month off, has no trial behind it in the sources reviewed for this article. If you plan to go past 8 to 12 weeks, talk to a doctor first.
Ashwagandha cortisol dosage and best time to take
Trial doses for cortisol and stress ranged from 225 to 600 mg a day of root or root-and-leaf extract. Chandrasekhar used 300 mg twice a day. The 8-week dose trial compared 250 and 600 mg a day. Lopresti used 240 mg a day. The Prolanza trial used one 300 mg sustained-release capsule a day.
In several studies, 500 to 600 mg a day worked better than lower doses, according to the NIH review. An international taskforce from the World Federation of Societies of Biological Psychiatry and the Canadian Network for Mood and Anxiety Treatments provisionally recommends 300 to 600 mg a day of root extract standardized to 5% withanolides for generalized anxiety disorder. The taskforce says a stronger recommendation needs more data.
These are trial doses, not instructions. Labels list different things, including extract weight, root powder weight and withanolide percentage. One trial in the NIH review used 12,000 mg a day of whole-root granules, equal to 6,000 mg of root powder. Check which number your label shows, and ask a doctor or pharmacist before you start.
Timing is open. The sources reviewed for this page include no head-to-head test of morning against evening dosing. Several trials split the dose into 2 capsules a day, and the Prolanza trial used 1. Follow your product label, and keep a steady schedule.
Does ashwagandha reduce belly fat?
The trials measured body weight and BMI, not belly fat.
The idea starts with cortisol. Research links chronically high cortisol with stronger appetite and fat storage, according to Healthline's review.
A 2017 trial of 52 stressed adults gave 300 mg twice a day for 8 weeks. Body weight fell about 3% on ashwagandha and about 1.5% on placebo, and food cravings dropped. A 2025 trial of 100 adults ran 24 weeks at the same dose and reported 8.46 kg lost on ashwagandha against 2.41 kg on placebo.
The 2025 result is large for a supplement and comes from one center. Treat it as a result waiting for a second trial. Neither abstract reports a measure of belly fat. A 12-week trial in 120 overweight adults with fatigue found no drop in perceived stress, though fatigue fell.
Stressed adults lost a little more weight on ashwagandha in two trials. Nobody has shown it targets belly fat. Lifestyle changes with a longer track record are covered in the section on other ways to lower cortisol.
Why don't doctors recommend ashwagandha?
Many stay cautious. Some discuss it case by case, and the 2022 taskforce guideline gives provisional doses for anxiety. Five reasons come up most in the NIH and NCCIH material.
- No agreed product or dose. Trials used different extracts and amounts, so doctors have no standard to follow.
- Small, short trials. Most ran 6 to 12 weeks, and NIH notes most were run within a traditional medical system, so the effect in other settings is unclear.
- Unknown long-term safety. NIH says safety beyond about 3 months has not been established.
- Safety signals. Reports include liver injury, thyroid changes, drug interactions and the 2026 adrenal case.
- Supplement rules. The FDA does not approve supplements before they're sold, so quality depends on the maker and on independent testing.
Doctors also start from a different question. High cortisol often has a cause, such as chronic stress, steroid medication like prednisone, or a pituitary or adrenal condition. A doctor wants the cause found before any supplement enters the plan.
Downsides and side effects of ashwagandha
Short-term use is usually well tolerated. Common side effects are mild: stomach upset, loose stools, nausea and drowsiness.
Liver injury is rare but documented. In five reported cases, people took 450 to 1,350 mg a day for 1 week to 4 months and developed signs such as jaundice, itching, nausea or abdominal discomfort. They improved after stopping. Some products held other ingredients, and not every product was independently tested.
Thyroid hormones shift too. In a 50-person trial of people with subclinical hypothyroidism, 300 mg twice a day for 8 weeks lowered TSH and raised T3 and T4. Three case reports describe thyrotoxicosis in women, and symptoms resolved after stopping.
NIH lists interactions with diabetes drugs, blood pressure drugs, immunosuppressants, sedatives and thyroid medication. NCCIH adds anti-seizure drugs and advises against use before surgery and with autoimmune or thyroid disorders.
NCCIH says to avoid ashwagandha during pregnancy and not to use it while breastfeeding. Denmark banned it in 2023, and France's food safety agency advised against it in pregnancy, breastfeeding and endocrine disorders in 2024. The American Herbal Pharmacopoeia disputes reports linking the root to abortions. Ashwagandha might also raise testosterone, so experts advise against it for hormone-sensitive prostate cancer.
The 2026 case report: when cortisol goes too low
In January 2026, Endocrinology, Diabetes & Metabolism Case Reports published the case of a 55-year-old postmenopausal woman who took about 950 mg of ashwagandha a day for more than a year. A local practitioner had prescribed it for knee osteoarthritis. She gained 10 kg in a year and developed facial puffiness and Cushingoid features. Tests showed low basal cortisol and a suboptimal response to an ACTH stimulation test, findings consistent with adrenal insufficiency. Her doctors linked the suppression of her HPA axis, the body's stress-hormone control system, to ashwagandha. At follow-up the suppression had not reversed, and she still needed hydrocortisone.
The authors note 950 mg a day far exceeds the doses typically used in clinical trials. The trials in the table ran 225 to 600 mg.
Two earlier reports exist. A 2022 case described a 41-year-old woman who took 858.6 mg a day of extract for 10 weeks and developed suppressed adrenal function. It returned to normal 2 weeks after she stopped.
A case report does not show how often this happens, and it does not prove ashwagandha was the only cause. Both reported doses sit above the trial range, so the cases say little about short courses at trial doses. The authors say clinicians and the public should know excessive doses and prolonged use are linked to Cushingoid features and sustained HPA axis suppression.
A 2025 review of ashwagandha cortisol trials found study lengths from 30 to 112 days and noted none evaluated adrenal function or long-term effects. A supplement built to lower cortisol still causes problems when it lowers it too far.
Myth: Natural supplements carry no real risk.
Fact: NIH documents liver, thyroid and interaction reports, and the 2026 case authors describe herbal products as not inherently benign.
Myth: Lower cortisol is always better.
Fact: Low cortisol is a medical condition. Trials aim for a normal level in stressed adults.
Run the 8-point safety check before you buy
Tick each box matching your situation. The check follows the cautions in the NIH ODS and NCCIH fact sheets. It runs in your browser and saves nothing.
This list is not complete. Medicines and recommendations change. A pharmacist will check your exact medicines against any supplement.
How to choose an ashwagandha supplement
Trials used standardized extracts, so the label is your starting point.
- Look for the plant part. Most trials used root extract, and a few used root and leaf.
- Look for the extract amount per day in mg. Root powder weight alone tells you less.
- Look for a withanolide percentage. The taskforce dose above refers to extract standardized to 5%.
- Look for third-party testing from a group such as USP or NSF. Healthline also advises choosing a company with third-party verification.
- Skip multi-herb blends if you want a clear read on one ingredient. Some of the liver injury cases involved combination products.
The FDA does not approve dietary supplements before sale, according to NCCIH, so the label is the maker's word until a testing group confirms it.
Other ways to lower cortisol, with the evidence behind them
Ashwagandha is one option among several. Healthline's review lists habits with their own research, shown here next to ashwagandha.
| Method | What the research reports | Caveat |
|---|---|---|
| Consistent sleep | Chronic sleep problems, such as insomnia and shift work, link to higher cortisol. Standard advice is fixed bed and wake times and no caffeine in the 6 hours before bed. | The links are associations |
| Regular moderate exercise | Hard sessions raise cortisol briefly and lower it hours later. Healthline suggests 150 to 200 minutes a week of mostly low to moderate exercise. | Overdoing it works against you |
| Mindfulness and slow breathing | Mindfulness training lowered cortisol in 52 older adults with type 2 diabetes. A 2019 review found diaphragmatic breathing lowered stress and cortisol. | Small groups |
| Food pattern | One study found a diet high in added sugar, refined grains and saturated fat raised cortisol compared with one rich in whole grains, fruit, vegetables and unsaturated fats. | One study |
| Fish oil | A cohort of 2,724 people linked higher blood omega-3 with lower cortisol and inflammation. | Observational, so cause is unproven |
| Ashwagandha | Randomized trials of 30 to 90 days found lower cortisol than placebo. | Small, short, long-term safety unknown |
Start with sleep if yours is off. If you wake unrefreshed, read You Slept 8 Hours. So Why Are You Still Exhausted? and plan your night with the Bedtime Calculator. The Sleep Debt Tracker shows your weekly shortfall, and the Clocks Go Back and Fall Back Sleep Planner builds a gradual schedule before the clocks change. If stress feels constant, the 9 warning signs your nervous system is stuck in survival mode help you name what's happening. Weighing magnesium too? Compare forms with the Magnesium Finder.
Questions to bring to your doctor
Take this list to an appointment, especially if you have constant fatigue, weight change or poor sleep. If tiredness is your main symptom, take the free fatigue assessment first and bring the result.
- Do my symptoms need a cortisol test, and at what time of day should it happen?
- Does anything I take interact with ashwagandha?
- Should we check my liver and thyroid blood tests before I start?
- How long should I try it before we review?
- What else might explain how I feel?
Frequently asked questions
Does ashwagandha lower cortisol?
In most randomized trials, yes. A 2026 meta-analysis of 23 trials and 1,706 people found lower cortisol than placebo. The trials are small, short and mostly from India, and results vary by extract and dose.
How long does ashwagandha take to lower cortisol?
Trials measured results at 30, 60 and 90 days. One reported lower saliva cortisol at 30 days, and the 28% drop in blood cortisol came at 60 days. Long-term safety has not been established, so talk to a doctor about duration.
What dose lowered cortisol in trials?
Doses ranged from 225 to 600 mg a day of extract. In several studies, 500 to 600 mg a day beat lower doses. Treat these as trial doses and check your product label and your doctor.
What is the best time to take ashwagandha for cortisol?
No head-to-head trial in the sources reviewed here compares morning with evening dosing. Trials used 1 or 2 doses a day. Follow your product label and keep a steady schedule.
Does ashwagandha reduce belly fat?
No trial has measured belly fat directly. Two trials in stressed or overweight adults found more weight loss than placebo, about 3% against 1.5% over 8 weeks in one. The idea is plausible but unproven for belly fat.
Why don't doctors recommend ashwagandha?
Doctors point to missing standard doses, small and short trials, unknown long-term safety, reports of liver and thyroid problems, and loose supplement regulation. Some clinicians still discuss it case by case.
What are the downsides of ashwagandha?
Mild stomach upset, loose stools, nausea and drowsiness are most common. Rare liver injury, thyroid changes, drug interactions and a 2026 report of suppressed adrenal function are the serious concerns.
Does ashwagandha lower cortisol too much?
Trials report average drops in stressed adults, not dangerously low levels. Case reports from 2022 and 2026 describe adrenal suppression after prolonged or high-dose use. No data show how often this happens, so avoid high doses or long courses without medical advice.
Keep reading
- See the full benefits picture in our ashwagandha research review
- Compare it with another adaptogen in Ashwagandha vs Rhodiola
- Start with the basics in our guide to what adaptogens are
- Learn how adaptogens combine in Adaptogen Stacks
- Read the broader evidence in our guide to whether adaptogens work
- Compare adaptogens with caffeine for energy and focus
- Match an adaptogen to your symptoms with the Which Adaptogen Is Right for You quiz
Check your stress and recovery
Take the free 2-minute Stress & Recovery Self-Assessment to see where your stress and recovery stand. It does not measure cortisol and does not replace a test from your doctor.
Sources reviewed
- NIH Office of Dietary Supplements, Ashwagandha fact sheet for health professionals (updated May 2, 2025)
- NCCIH, Ashwagandha: Usefulness and Safety (March 2023)
- Chandrasekhar K, et al. Indian Journal of Psychological Medicine, 2012
- Hormonal modulation with Withania somnifera: systematic review and meta-analysis. Planta Medica, 2026
- Javid J, et al. From herbal hope to hormonal havoc: chronic ashwagandha use and HPA axis suppression. Endocrinology, Diabetes & Metabolism Case Reports, 2026
- Fry et al. Ashwagandha and adrenal function, case report, 2022
- Choudhary D, et al. Body weight management in adults under chronic stress. J Evid Based Complementary Altern Med, 2017
- Ashwagandha root extract on stress and weight management in adults. Medicine and Life, 2025
- Healthline, 11 Natural Ways to Lower Your Cortisol Levels (updated February 17, 2026)
I am not a doctor or healthcare professional. The information in this article is based on publicly available research, scientific studies, and trusted medical resources. It is provided for educational purposes only and should not replace professional medical advice. Always speak with a qualified healthcare provider before starting any supplement.
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