Ashwagandha

Pronunciation: ash-wah-GAN-dah.

Generic name
ashwagandha (Withania somnifera); also known as Indian ginseng or winter cherry
Drug class
Not applicable -- ashwagandha is an adaptogenic herb sold as a dietary/food or complementary-medicine supplement, not a regulated drug class
Form
Capsules, tablets, powders, and standardised root/extract preparations
Route
Oral (capsule, tablet, powder, or extract)
Legal status
Dietary/food supplement in the United States, United Kingdom, European Union, and New Zealand (UK and EU currently under active regulatory safety review); typically a licensed/listed low-risk complementary-medicine product (Natural Health Product in Canada, 'Listed' AUST L medicine in Australia) -- not a prescription or pharmacy-only medicine in any of these 6 markets.

Availability and supply rules vary by country

Trade names by country: United States

Australia: · Full directory

What ashwagandha (Withania somnifera); also known as Indian ginseng or winter cherry is and how it works

Ashwagandha is an evergreen shrub (Withania somnifera) native to parts of India, Africa, and the Middle East, used for centuries in Ayurvedic medicine. Its root extract, standardised for withanolide compounds, is sold as a dietary/food supplement promoted for stress, anxiety, sleep, male fertility, and athletic performance. It is not a regulated prescription or over-the-counter medicine in the United States, United Kingdom, European Union, or New Zealand; in Canada and Australia it is available through each country's lower-risk complementary/natural-health-product licensing pathway, still distinct from prescription-drug approval. (1)

Ashwagandha taken as a conventionally formulated oral supplement at recommended amounts for up to about 3 months is generally tolerated by most healthy adults, though evidence that it reliably treats any specific medical condition is still preliminary. If you are considering an ashwagandha supplement, are pregnant or breastfeeding, have thyroid disease or an autoimmune condition, take other medicines, or have any liver problems, discuss this with your healthcare provider first.

Mechanism of action: how ashwagandha (Withania somnifera); also known as Indian ginseng or winter cherry works

Ashwagandha's principal bioactive compounds, withanolides (including withanolide A and withaferin A), have shown anti-inflammatory, antioxidant, and mild sedative/anxiolytic-type activity in laboratory and animal studies, along with signals of stimulating thyroid hormone release/peripheral T4-to-T3 conversion and modulating cortisol and immune-cell activity -- providing the pharmacological basis for its interactions with thyroid, immunosuppressant, sedative, diabetes, and blood-pressure medicines. (2) (9) (1)

What ashwagandha (Withania somnifera); also known as Indian ginseng or winter cherry is used for

Stress and anxiety

Ashwagandha is one of the most commonly used supplements for stress and anxiety. Some studies suggest certain standardised ashwagandha preparations may help reduce stress-related symptoms, but overall evidence is still described as preliminary/limited by NIH NCCIH rather than conclusively proven. (1)

Sleep

Some research suggests certain ashwagandha preparations may modestly improve sleep quality or help with insomnia, though the evidence base remains limited and preparations studied vary. (1)

Male fertility and athletic performance

Some limited evidence suggests that taking ashwagandha for 2 to 4 months may increase testosterone levels and sperm quality in some studies; it is also promoted for athletic performance, though the supporting evidence for these uses is preliminary and not considered conclusive. (1)

Other traditionally claimed uses

Ashwagandha has a long history of traditional Ayurvedic use for many other conditions, but for most of these claimed uses there is not enough reliable modern clinical evidence to confirm a meaningful benefit. (1)

Before taking ashwagandha (Withania somnifera); also known as Indian ginseng or winter cherry

Do not take / not appropriate for

  • Ashwagandha should be avoided during pregnancy and should not be used while breastfeeding. There is a contested but real traditional and animal-research signal suggesting some ashwagandha preparations may stimulate the uterus; while modern expert opinion on this specific risk is not unanimous, current mainstream guidance is to avoid use in pregnancy given the overall insufficient safety data. (pregnancy and breastfeeding) (1)
  • People with an overactive thyroid (hyperthyroidism) or thyrotoxicosis should use particular caution, since ashwagandha can stimulate thyroid hormone release and has been linked to case reports of thyrotoxicosis, including one presenting with a fast, irregular heartbeat. (hyperthyroidism / thyrotoxicosis) (1) (9)

Tell your clinician about

  • Any thyroid condition or use of thyroid hormone replacement medicines (such as levothyroxine), because ashwagandha can raise thyroid hormone levels and has been linked to case reports of thyrotoxicosis on top of thyroid medicine.
  • Any autoimmune condition (such as lupus or rheumatoid arthritis) or use of immunosuppressant medicines, because ashwagandha may stimulate immune activity and could work against the intended effect of immune-suppressing treatment.
  • Any liver problems, or any past reaction to an ashwagandha supplement, given rare but documented reports of liver injury.
  • Diabetes or blood-pressure medicines you take, because ashwagandha may add to their blood-sugar- or blood-pressure-lowering effects.
  • Any sedative, sleep, or anti-anxiety medicines you take, including benzodiazepines, because ashwagandha has its own sedative effect and preliminary evidence suggests it may add to theirs.
  • Pregnancy, plans for pregnancy, or breastfeeding.
  • Any planned surgery, since sedative and blood-sugar effects may be relevant to anaesthesia and perioperative care -- follow your surgical team's specific instructions.
(1) (9)

How to take ashwagandha (Withania somnifera); also known as Indian ginseng or winter cherry

  • Follow the amount stated on the product label, or the amount recommended by your healthcare provider -- there is no single official medical dose, since ashwagandha is not a regulated medicine.
  • Conventionally formulated oral ashwagandha is generally tolerated by most healthy adults for up to about 3 months of use studied in research; ask your healthcare provider about safety for longer-term use.
  • If you are having surgery, tell your surgical team you take an ashwagandha supplement well in advance.
(1)

Procedures and treatment changes

Tell the treating team before surgery, procedures, or any medicine change. Do not alter treatment without the responsible clinician. (1) (2) (3) (4) (5) (6) (7) (8) (9)

Missed dose

Because ashwagandha is a supplement rather than a prescribed medicine with a strict dosing schedule, a missed dose is not usually a medical concern -- simply resume your normal use. If a healthcare provider gave you a specific schedule for a particular reason, follow their guidance.

Overdose

Taking a very large amount of an ashwagandha supplement is unlikely to cause a classic medical emergency, but can worsen digestive side effects (nausea, vomiting, diarrhoea) and may raise the risk of liver- or thyroid-related symptoms. If you develop fatigue, poor appetite, dark urine, yellowing of the skin or eyes, a fast or irregular heartbeat, or persistent vomiting after taking an ashwagandha product, contact a poison control centre or seek medical attention promptly. (1) (2) (9)

Side effects

Side effects and their urgency vary; report severe, persistent, or concerning symptoms.

Drowsiness.

What to notice: Drowsiness.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Stomach upset.

What to notice: Stomach upset.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Diarrhoea or vomiting.

What to notice: Diarrhoea or vomiting.

What to do: Discuss persistent or troublesome symptoms with the treating clinician or pharmacist. (1)

Serious warnings

Liver injury — high caution

Symptoms: Fatigue, nausea, poor appetite, dark urine, or yellowing of the skin or eyes (jaundice), usually appearing within weeks to a few months of starting the supplement.

Action: Contact your healthcare provider promptly for liver testing and further guidance if any of these symptoms occur; a clinician will assess whether the supplement needs to be discontinued. LiverTox rates ashwagandha as a likely cause of clinically apparent liver injury (likelihood score B), though this remains rare overall. (2)

Thyrotoxicosis (excess thyroid hormone) — high caution

Symptoms: A fast or irregular heartbeat, tremor, unexplained weight loss, heat intolerance, or anxiety-like symptoms, particularly if you also take thyroid hormone medicine.

Action: Seek prompt medical attention for a fast or irregular heartbeat or other symptoms of an overactive thyroid; a documented case report describes ashwagandha-associated thyrotoxicosis presenting this way. Tell your prescriber about any ashwagandha use if you have thyroid disease or take thyroid medicine. (9) (1)

Interactions

  • Sedatives, benzodiazepines, and other anti-anxiety or sleep medicines: ashwagandha has its own sedative effect, and preliminary evidence suggests it may increase drowsiness and other effects of these medicines. Tell your prescriber before combining them. (1)
  • Immunosuppressant medicines: ashwagandha may stimulate immune system activity, which could work against medicines intended to suppress the immune system (for example after a transplant or for an autoimmune condition). Discuss this with your prescriber before use. (1)
  • Thyroid hormone medicines (such as levothyroxine): ashwagandha can raise thyroid hormone levels, and case reports describe thyrotoxicosis developing when combined with thyroid medicine. Tell your prescriber if you take thyroid medicine before starting ashwagandha. (9) (1)
  • Diabetes medicines: ashwagandha may lower blood sugar, which combined with diabetes medicines could increase the risk of blood sugar dropping too low. Monitor blood sugar closely and discuss with your prescriber. (1)
  • Blood pressure medicines: ashwagandha may lower blood pressure, which combined with blood-pressure-lowering medicines could increase the risk of blood pressure dropping too low. Discuss with your prescriber. (1)

Pregnancy, breastfeeding, kidney/liver function, age

Pregnancy

Ashwagandha should be avoided during pregnancy. Safety has not been established, and there is a contested but real traditional/animal-research signal regarding possible uterine-stimulant effects; current mainstream guidance is to avoid use. (1) (2) (3) (4) (5) (6) (7) (8) (9)

Breastfeeding

Ashwagandha should not be used while breastfeeding, per NIH NCCIH guidance -- discuss any supplement use with your healthcare provider while nursing. (1) (2) (3) (4) (5) (6) (7) (8) (9)

Children

Evidence on ashwagandha's safety and effectiveness in children is limited; use only under a healthcare provider's guidance. (1) (2) (3) (4) (5) (6) (7) (8) (9)

Elderly

No specific dose adjustment is described in the sources reviewed, but older adults are more likely to take thyroid, diabetes, blood-pressure, sedative, or immunosuppressant medicines, making ashwagandha's interaction profile especially relevant to discuss with a healthcare provider. (1) (2) (3) (4) (5) (6) (7) (8) (9)

Hepatic_impairment

People with existing liver problems should consult a healthcare provider before use, given the documented (though rare) liver-injury signal associated with ashwagandha. (1) (2) (3) (4) (5) (6) (7) (8) (9)

Monitoring

Before starting

  • Review of all current medicines and supplements, especially thyroid, diabetes, blood-pressure, sedative, and immunosuppressant medicines
  • Discussion of any personal history of liver disease, thyroid disease, or autoimmune conditions

During treatment

  • Watch for symptoms of liver injury (fatigue, poor appetite, dark urine, jaundice).
  • Watch for symptoms of an overactive thyroid (fast or irregular heartbeat, tremor, unexplained weight loss) if you have thyroid disease or take thyroid medicine.
  • Monitor blood sugar and blood pressure more closely if you take medicines for these conditions.
(2) (9)

Storage

Store ashwagandha capsules, tablets, or powder at room temperature, away from moisture and direct light, and follow any specific storage instructions on the product label.

Professional information

Clinician-facing context only. Ashwagandha is not a regulated drug in most of the markets reviewed, so there is no official prescribing label -- this summarises NIH NCCIH, NIH LiverTox, a peer-reviewed case report, and national supplement-regulator material; verify against current sources before advising patients.

General (no official medical dose exists)

Indication: Stress, anxiety, sleep, male fertility (preliminary evidence only)

Dose summary: No standardised, regulator-set therapeutic dose exists. Clinical trials most commonly studied standardised root-extract doses in the range of roughly 300-600 mg/day for up to about 8-12 weeks, but there is no single validated standard dose across products.

Renal context: Not established in the sources reviewed. (1)

Mechanism of action

Hepatic guidance

Idiosyncratic hepatotoxicity has been reported with ashwagandha supplements (LiverTox likelihood score B), typically presenting as cholestatic or mixed-pattern liver injury 2-12 weeks after starting; advise patients with pre-existing liver disease to consult a healthcare provider before use and to seek care promptly for jaundice, dark urine, or unexplained fatigue.

Overdose note

No well-characterised acute overdose syndrome is described for oral ashwagandha in the sources reviewed; very high intake may worsen gastrointestinal side effects and theoretically raises hepatotoxicity and thyroid-stimulation risk. Manage symptomatically and per local poison-control guidance. (2) (9) (1)

Frequently asked questions

Is ashwagandha a regulated medicine in the US, UK, Europe, Canada, Australia, and New Zealand?

No. Ashwagandha is not a prescription or pharmacy-regulated medicine in any of these 6 markets. It is sold as a food/dietary supplement in the US, UK, EU, and New Zealand (the UK and EU are both actively reviewing its safety as of 2024-2026), and through a lower-risk complementary/natural-health-product licensing pathway in Canada and Australia -- none of these are equivalent to prescription-drug approval. (3) (4) (5) (6) (7) (8)

Does ashwagandha really help with stress, anxiety, or sleep?

Evidence is still preliminary/limited according to NIH NCCIH. Some studies of specific standardised preparations suggest a benefit for stress and sleep, but the overall evidence is not yet strong enough to consider these benefits proven or consistent across all products. (1)

Can ashwagandha harm the liver?

Rare but real cases of liver injury have been reported. LiverTox rates ashwagandha as a likely cause of clinically apparent liver injury (likelihood score B). Contact a healthcare provider promptly if you develop fatigue, poor appetite, dark urine, or yellowing of the skin or eyes while taking an ashwagandha supplement. (2)

Is ashwagandha safe if I have a thyroid condition?

Use caution. Ashwagandha can raise thyroid hormone levels, and a documented case report describes thyrotoxicosis (excess thyroid hormone) developing in a person taking it. If you have thyroid disease or take thyroid hormone medicine such as levothyroxine, discuss ashwagandha with your healthcare provider first. (9) (1)

Can I take ashwagandha during pregnancy?

No -- ashwagandha should be avoided during pregnancy and should not be used while breastfeeding, per NIH NCCIH guidance. Safety has not been established, and there is a contested but real historical concern about possible uterine-stimulant effects. (1)

What is the mechanism of action of ashwagandha (Withania somnifera); also known as Indian ginseng or winter cherry?

Ashwagandha's principal bioactive compounds, withanolides (including withanolide A and withaferin A), have shown anti-inflammatory, antioxidant, and mild sedative/anxiolytic-type activity in laboratory and animal studies, along with signals of stimulating thyroid hormone release/peripheral T4-to-T3 conversion and modulating cortisol and immune-cell activity -- providing the pharmacological basis for its interactions with thyroid, immunosuppressant, sedative, diabetes, and blood-pressure medicines. (2) (9) (1)

What is the generic name of Ashwagandha?

The generic name is ashwagandha (Withania somnifera); also known as Indian ginseng or winter cherry. (1) (3)

What class of drug is ashwagandha (Withania somnifera); also known as Indian ginseng or winter cherry?

Ashwagandha is classed as: Not applicable -- ashwagandha is an adaptogenic herb sold as a dietary/food or complementary-medicine supplement, not a regulated drug class. (1) (3)

References

  1. Ashwagandha: Is it helpful for stress, anxiety, or sleep?National Center for Complementary and Integrative Health (NCCIH), part of NIH · United States · accessed 2026-07-29 · source 1
  2. Ashwagandha -- LiverTox: Clinical and Research Information on Drug-Induced Liver InjuryLiverTox, National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) / NIH, hosted on NCBI Bookshelf · United States · accessed 2026-07-29 · source 2
  3. Dietary Supplements (FDA)U.S. Food and Drug Administration (FDA) · United States · accessed 2026-07-29 · source 3
  4. FSA call for evidence on ashwagandha in food supplements (2024, ongoing safety review)UK Food Standards Agency (FSA) · United Kingdom · accessed 2026-07-29 · source 4
  5. EU regulatory status and safety review of ashwagandha in food supplementsEuropean Food Safety Authority (EFSA) and EU national food-safety agencies · European Union · accessed 2026-07-29 · source 5
  6. Ashwagandha (Withania somnifera) as a licensed Natural Health Product (NHP), e.g. KSM-66 Ashwagandha (NPN 80047973, NPN 80102381)Health Canada, Natural and Non-prescription Health Products Directorate (NNHPD) / Licensed Natural Health Products Database · Canada · accessed 2026-07-29 · source 6
  7. Medicines containing Withania somnifera (Withania, Ashwagandha) -- TGA safety informationTherapeutic Goods Administration (TGA), Australia · Australia · accessed 2026-07-29 · source 7
  8. Regulation of Dietary Supplements (Medsafe)Medsafe (New Zealand Medicines and Medical Devices Safety Authority) and Ministry for Primary Industries (MPI) · New Zealand · accessed 2026-07-29 · source 8
  9. Ashwagandha as a Unique Cause of Thyrotoxicosis Presenting With Supraventricular TachycardiaPeer-reviewed case report, hosted on PubMed Central (NIH/NCBI) · Not country-specific (clinical case report) · accessed 2026-07-29 · source 9

Brand names by country

Single-ingredient ashwagandha (Withania somnifera); also known as Indian ginseng or winter cherry names are shown separately by country. Product availability, strengths, and supply rules can change; combination products are not included here.

Priority countries

United States

  • Herb PharmHerb Pharm
  • Organic IndiaOrganic India
  • HimalayaHimalaya
  • Oregon's Wild HarvestOregon's Wild Harvest
  • FGOFGO
  • Herbal HillsHerbal Hills
  • FuturebioticsFuturebiotics
  • Amazing IndiaAmazing India
  • Omica OrganicsOmica Organics
  • Maui MedicinalMaui Medicinal
View brands in additional countries.

This page provides general reference information about ashwagandha as a dietary/food supplement. It is not medical advice, a treatment recommendation, or a substitute for guidance from a qualified healthcare provider, especially if you take other medicines, are pregnant or breastfeeding, or have a thyroid, liver, or autoimmune condition.

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