Ashwagandha
What ashwagandha (Withania somnifera) is, what trials found for stress and sleep, and the liver, thyroid, pregnancy and medicine cautions to know before using it.
Content last updated . This page has not been medically reviewed.
Safety first. Supplements can cause side effects and interact with medicines. Read mushroom safety and interactions before you use any mushroom product.
What is Ashwagandha good for?
What the body uses it for, and how strong the evidence is. A normal job in the body is not proof that extra supplements add benefit; each card says which.
Stress and perceived stress
Preliminary or mixedSeveral small trials suggest ashwagandha extracts lower stress scores compared with placebo. The certainty of the evidence is low and products differ.
Supplements: Promising but limited; results from one extract do not carry over to another.
Sleep and insomnia
Preliminary or mixedA meta-analysis of 5 trials found a small improvement in sleep, larger in adults with insomnia. NCCIH says some preparations may be effective.
Supplements: Small effect; few trials; long-term safety data limited.
Anxiety
Preliminary or mixedSome meta-analyses found lower anxiety scores, but NCCIH calls the evidence unclear and trials varied greatly.
Supplements: Mixed evidence; not a substitute for treatment prescribed by a clinician.
Cortisol levels
Preliminary or mixedA meta-analysis found lower serum cortisol than placebo. This is a lab marker, not proof of feeling or functioning better.
Supplements: Marker change only.
Testosterone and sperm quality in men
Preliminary or mixedNCCIH says limited evidence suggests 2 to 4 months of use may raise testosterone and sperm quality in men.
Supplements: Limited; a blood number is not the same as better health.
Thyroid hormone levels
Preliminary or mixedOne small pilot trial (50 adults with subclinical hypothyroidism) reported changed TSH, T3 and T4 compared with placebo. This is preliminary.
Supplements: Preliminary only; people on thyroid medicine should ask a prescriber first.
Traditional use in Ayurveda
Lab or animal research onlyNCCIH says it has been used as a medicinal plant for thousands of years, especially in Ayurveda. This history is not evidence that a supplement works today.
Supplements: Traditional use is not evidence of benefit.
Withanolides and lab findings
Lab or animal research onlyIts withanolides are associated with anti-inflammatory and antioxidant effects in laboratory research; no human benefit is established from this.
Supplements: No human benefit shown from lab findings.
Connected topics
Open a group to see how each topic connects and how strong the evidence is.
Health goals (5)
- Better SleepPreliminary or mixed
A meta-analysis of 5 trials (400 adults) found a small effect on sleep, larger in people with insomnia. The trials are few and used different extracts.
- Sleep QualityPreliminary or mixed
Sleep scores were somewhat better than placebo in a meta-analysis of 5 trials; long-term safety data are limited.
- Stress ReductionPreliminary or mixed
Meta-analyses of small trials found lower perceived-stress scores than placebo, but the certainty of the evidence was rated low and the products studied differ.
- Anxiety SupportPreliminary or mixed
NCCIH calls the evidence on anxiety unclear. Meta-analyses found lower anxiety scores, but with very high variation between trials and low certainty.
- Men’s VitalityPreliminary or mixed
NCCIH says limited evidence suggests 2 to 4 months of use may raise testosterone and sperm quality in men. A higher blood number is not proof of better health.
Body systems (5)
- Hepatic / Liver SystemDocumented risk
Rare but documented liver injury (jaundice, itching, nausea). Cases were mostly self-limited, but people with existing liver disease in an Indian series developed liver failure and died.
- Endocrine SystemDocumented risk
NCCIH advises against use in thyroid disorders, and case reports describe thyrotoxicosis after use.
- Immune SystemDocumented risk
NCCIH says it might interact with immunosuppressants and is not recommended for people with autoimmune disorders.
- Sleep & RecoveryPreliminary or mixed
A small effect on sleep was found in a meta-analysis of 5 trials, mostly of root extracts.
- Stress & MoodPreliminary or mixed
Studied mainly for stress and anxiety scores; evidence is promising but limited and certainty is low.
Body parts (3)
- LiverDocumented risk
Case series document supplement-linked liver injury, usually cholestatic or mixed and often reversible after stopping.
- Immune SystemDocumented risk
Possible interaction with immunosuppressants; not recommended in autoimmune disorders.
- ThyroidDocumented risk
Case reports describe thyrotoxicosis after use, and NCCIH advises caution in thyroid disorders and with thyroid hormone medicines.
Functional actions (3)
- Sleep RegulationPreliminary or mixed
Small effect on sleep in a meta-analysis of 5 trials.
- Stress ReductionPreliminary or mixed
Lower stress scores than placebo in small trials; certainty low.
- AdaptogenicPreliminary or mixed
Often labelled an adaptogen, but this is a contested label rather than a regulated category; the supporting human evidence is the stress and sleep trials.
Root causes (4)
- Medication Side EffectsDocumented risk
NCCIH says it might interact with diabetes, blood pressure, immunosuppressant, sedative, anti-seizure and thyroid hormone medicines. Ask a pharmacist.
- Autoimmune DysfunctionDocumented risk
NCCIH says it is not recommended for people with autoimmune disorders.
- Chronic StressPreliminary or mixed
Studied in adults with stress; trials suggest lower stress scores, with low-certainty evidence.
- Poor SleepPreliminary or mixed
Small improvement in sleep seen in a meta-analysis, larger in adults with insomnia.
Biomarkers (3)
- CortisolPreliminary or mixed
A meta-analysis of 9 trials found lower serum cortisol than placebo. Cortisol is a lab marker and not proof that people feel or function better.
- TSHPreliminary or mixed
One pilot trial reported changed TSH, T3 and T4 in subclinical hypothyroidism; case reports show low TSH and thyrotoxicosis after use. Anyone on thyroid medicine should ask a prescriber.
- TestosteronePreliminary or mixed
Limited evidence that 2 to 4 months of use may raise testosterone in men (NCCIH); also why people with hormone-sensitive prostate cancer should avoid it.
Conditions & symptoms (4)
- Drug-Induced Liver DiseaseDocumented risk
Case series document herb-induced liver injury, usually cholestatic, mostly recovering after stopping but fatal in some people with existing chronic liver disease.
- Autoimmune DiseasesDocumented risk
NCCIH says ashwagandha is not recommended for people with autoimmune disorders and might interact with immunosuppressants.
- Primary InsomniaPreliminary or mixed
NCCIH says some preparations may be effective for insomnia, and a meta-analysis found larger effects in adults diagnosed with insomnia. Few trials; certainty is limited.
- ThyrotoxicosisDocumented risk
Case reports describe thyrotoxicosis after ashwagandha use that improved after stopping. These are rare single cases.
Documented risks and interactions (4)
- Liver injury (documented risk). Rare cases of liver injury are reported, with jaundice, itching and nausea after 2 to 12 weeks. Most recovered after stopping; people with existing chronic liver disease in an Indian series developed liver failure and died.
- Thyroid effects (documented risk). Case reports describe thyrotoxicosis after use. NCCIH advises people with thyroid disorders to avoid it or use it only with medical guidance.
- Pregnancy and breastfeeding (documented risk). NCCIH says ashwagandha should be avoided during pregnancy and not used while breastfeeding.
- Medicine interactions and surgery (documented risk). NCCIH says it might interact with diabetes, blood pressure, immunosuppressant, sedative, anti-seizure and thyroid hormone medicines, and is not recommended before surgery or in autoimmune disorders; people with hormone-sensitive prostate cancer should avoid it.
What ashwagandha is
Ashwagandha is Withania somnifera (L.) Dunal, a member of the nightshade family (Solanaceae). [5] NIH describes it as an evergreen shrub found in parts of India, Africa and the Middle East that contains substances called withanolides. [1] Supplements typically contain root, leaf, or root and leaf extracts. [1] It is sometimes called "Indian ginseng", but it is a different plant family from true ginseng (Panax, family Araliaceae). [5]Is it an "adaptogen"?
"Adaptogen" is a contested term, not a regulated category. A 2026 review names Withania somnifera among the prominent adaptogens, [6] and a 2024 meta-analysis calls it an adaptogenic herb. [7] NIH's page describes the evidence, not a classification. [1] See what adaptogens are for how the word is used.Traditional use (not proof)
NIH says ashwagandha has been used as a medicinal plant for thousands of years, especially in traditional Ayurvedic medicine. [1] That history is part of its story, but it does not show that a supplement works today. See ashwagandha in Ayurveda.What research shows
| Use | What the sources found | Strength of evidence | Population and form studied |
|---|---|---|---|
| Sleep | A meta-analysis of 5 randomized trials (400 people) found a small but significant effect on sleep; larger in people with insomnia. [8] NIH says some preparations may be effective for insomnia. [1] | Promising but limited | Adults; ashwagandha extracts versus placebo |
| Stress | A meta-analysis of 9 trials (558 people) found lower Perceived Stress Scale scores and lower serum cortisol. [7] Another of 12 trials rated the certainty of evidence low. [9] | Promising but limited | Adults; various formulations |
| Anxiety | NIH says evidence about anxiety is unclear. [1] A 12-trial meta-analysis found lower anxiety scores but very high variation between trials. [9] | Mixed | Adults; various extracts |
| Testosterone and sperm quality | NIH: limited evidence that 2 to 4 months of use may raise testosterone and sperm quality. [1] | Insufficient evidence | Men; various preparations |
| Thyroid hormone levels | In a pilot trial of 50 adults with subclinical hypothyroidism, 600 mg of root extract daily for 8 weeks changed TSH, T3 and T4 compared with placebo. [10] | Preliminary, single centre | Adults aged 18 to 50 in India; root extract |
| Asthma, athletic performance, thinking, diabetes, menopause, female infertility | NIH: not enough evidence to say. [1] | Insufficient evidence | Not applicable |
| COVID-19 | NIH: not enough high-quality evidence. [1] | No good evidence of benefit | Not applicable |
Cortisol and thyroid levels are lab markers, not the same as how a person feels or functions. "Adrenal fatigue" is not a recognized diagnosis according to the Endocrine Society, which says no scientific proof supports it as a true medical condition. [11] See adrenal fatigue claims.
Thyroid reports
Case reports describe thyrotoxicosis (an overactive thyroid state) after ashwagandha use: a 47-year-old man with painless thyroiditis whose tests improved after stopping it, [12] and a 73-year-old woman with a fast heart rhythm and low TSH after two years of self-treatment for hypothyroidism. [13] These are rare single cases and cannot show how often it happens. People who take thyroid medicine should talk to their prescriber first; see ashwagandha and the thyroid.Forms matter
Root, leaf and whole-plant extracts are different products. [1] Results from one extract do not carry over to another; see root versus leaf extracts. Contamination has been reported: Memorial Sloan Kettering describes hemolytic anemia and abdominal pain after ashwagandha and mucuna pills that contained high amounts of lead. [4] See quality testing and certifications.Where to go next
Stress and anxiety trials, sleep trials, interactions with medicines, pregnancy, breastfeeding and children, and before surgery or with autoimmune disease.Frequently asked questions
Is ashwagandha safe?
It may be safe in the short term (up to 3 months) for some people, but rare liver injury cases are reported, and it should be avoided in pregnancy. [1]
Does ashwagandha lower cortisol?
A meta-analysis found lower serum cortisol in the groups that took ashwagandha formulations. [7] Cortisol is a lab marker, and lower cortisol is not proof that a person feels or functions better.
Who should talk to a clinician before using it?
People who are pregnant or breastfeeding, who have thyroid, autoimmune or liver conditions (the Indian case series found deaths in people with existing chronic liver disease [3]), who take medicines for diabetes, blood pressure, seizures or the thyroid, or who are about to have surgery. [1]
Is ashwagandha the same as ginseng?
No. "Indian ginseng" is a nickname. Ashwagandha is in the nightshade family, while Panax ginseng is in the Araliaceae family. [5]
What are the signs of a liver problem?
In the case series, people had jaundice, nausea, lethargy, itching and abdominal discomfort. [2] See liver safety and seek medical care.
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
Safety points first
- Liver. NIH's complementary health center says liver injury linked to ashwagandha supplements is rare, but a number of cases have been reported. [1] In one case series of five people, all developed jaundice (yellow skin or eyes) after 2 to 12 weeks, along with nausea, tiredness, itching or abdominal discomfort. No one developed liver failure and liver tests returned to normal within 1 to 5 months in four of them. [2] A series from India reported 8 single-ingredient cases; three people with existing chronic liver disease developed acute-on-chronic liver failure and died. [3] See Liver safety and supplements and ashwagandha side effects and liver injury reports.
- Pregnancy and breastfeeding. NIH says ashwagandha should be avoided during pregnancy and should not be used while breastfeeding. [1] Memorial Sloan Kettering Cancer Center says pregnant women should avoid it because it may raise the risk of miscarriage. [4]
- Thyroid, autoimmune conditions and surgery. NIH says ashwagandha is not recommended for people about to have surgery or for people with autoimmune or thyroid disorders. [1] Tell the surgical team about any supplement.
- Medicines. NIH says it might interact with diabetes and blood pressure medicines, immunosuppressants, sedatives, anti-seizure medicines and thyroid hormone medicines. [1] See how interactions work and ask a pharmacist.
- Hormone-sensitive prostate cancer. Because ashwagandha may raise testosterone, NIH says people with this cancer should avoid it. [1]
- Anxiety or depression treatment. Do not change a prescribed medicine on your own; ask the prescriber or pharmacist. If you are in crisis in the US, call or text 988.
Other safety notes
- Common effects. NIH lists drowsiness, stomach upset, diarrhea and vomiting in some people. [1]
- Short versus long term. NIH says it may be safe up to 3 months, and there is not enough information on long-term safety. [1]
- Antidepressants. A review of 1,816 adverse-event reports found ashwagandha listed with reboxetine, sertraline, escitalopram and paroxetine in reports of side effects such as diarrhea, muscle pain and nausea. [14]
- Children, older adults, kidney conditions. Not described in the sources we read for this page.
- Regulation. NIH says supplements are not approved by the FDA before they are sold. [1] See how supplements are regulated.
References
- National Center for Complementary and Integrative Health (NIH). Ashwagandha: Usefulness and Safety. Page dated March 2023. Read 2026-10-23.
- Björnsson et al. Ashwagandha-induced liver injury: A case series from Iceland and the US Drug-Induced Liver Injury Network. Liver international : official journal of the International Association for the Study of the Liver 2020. PubMed 31991029. Read 2026-10-23.
- Philips et al. Ashwagandha-induced liver injury-A case series from India and literature review. Hepatology communications 2023. PubMed 37756041. Read 2026-10-23.
- Memorial Sloan Kettering Cancer Center. Ashwagandha: Purported Benefits, Side Effects & More. Information About Herbs, Botanicals and Other Products. Read 2026-10-23.
- GBIF Secretariat. GBIF Backbone Taxonomy. Names checked through the species match API on 2026-10-23. Read 2026-10-23.
- Rao Y et al. Phyto adaptogens in stress management and health optimization: Current understanding and future perspectives. Complementary medicine research 2026. PubMed 42721096. Read 2026-10-23.
- Arumugam et al. Effects of Ashwagandha (Withania Somnifera) on stress and anxiety: A systematic review and meta-analysis. Explore (New York, N.Y.) 2024. PubMed 39348746. Read 2026-10-23.
- Cheah et al. Effect of Ashwagandha (Withania somnifera) extract on sleep: A systematic review and meta-analysis. PloS one 2021. PubMed 34559859. Read 2026-10-23.
- Akhgarjand et al. Does Ashwagandha supplementation have a beneficial effect on the management of anxiety and stress? A systematic review and meta-analysis of randomized controlled trials. Phytotherapy research : PTR 2022. PubMed 36017529. Read 2026-10-23.
- Sharma et al. Efficacy and Safety of Ashwagandha Root Extract in Subclinical Hypothyroid Patients: A Double-Blind, Randomized Placebo-Controlled Trial. Journal of alternative and complementary medicine (New York, N.Y.) 2018. PubMed 28829155. Read 2026-10-23.
- Endocrine Society. Adrenal Fatigue. Patient resource. Read 2026-10-23.
- Hayashi et al. Painless Thyroiditis by Withania somnifera (Ashwagandha). Cureus 2024. PubMed 38559552. Read 2026-10-23.
- Kamal et al. Ashwagandha as a Unique Cause of Thyrotoxicosis Presenting With Supraventricular Tachycardia. Cureus 2022. PubMed 35475098. Read 2026-10-23.
- Siwek et al. Harder, better, faster, stronger? Retrospective chart review of adverse events of interactions between adaptogens and antidepressant drugs. Frontiers in pharmacology 2023. PubMed 37829299. Read 2026-10-23.