Ashwagandha: What It Is and What to Check on the Label

Quick answer

• Ashwagandha (Withania somnifera) is a traditional herb. Supplements are usually root or root-and-leaf extracts, and research is on specific extracts at specific doses.
• Studies on stress and sleep are mostly small and short. The NCCIH says evidence on anxiety is unclear.
• Safety matters: possible liver injury, thyroid effects, medicine interactions, and avoidance in pregnancy and breastfeeding. Speak to a doctor first.
• On the label, check the plant part, powder or extract, standardisation (such as withanolides), milligrams per serving, add-ons and printed cautions.
• Look for named independent testing you can verify, and compare cost per day like for like.

What ashwagandha is

Ashwagandha (Withania somnifera) is a plant used in traditional Ayurvedic and Unani medicine. The NIH Office of Dietary Supplements says it is also known as Indian ginseng and winter cherry, though the health professional sheet notes it does not belong to the ginseng family. The NCCIH, part of the US National Institutes of Health, describes it as an evergreen shrub found in parts of India, Africa and the Middle East, and says it contains bioactive compounds including a group called withanolides.

The name comes from Sanskrit. The NIH health professional sheet explains that "ashwa" means horse and "gandha" means smell, because the plant's roots are said to smell like a wet horse.

In India, this is a familiar herb. That familiarity can make a label feel safe, but the supplement aisle is different from the kitchen cabinet. Supplements usually contain extracts, sometimes concentrated, from specific parts of the plant. The NIH says ashwagandha supplements usually contain extracts made from the plant's roots or from the roots and leaves, and the NCCIH says they typically contain root, leaf, or root and leaf extracts. Which part, which extract and what dose all vary, and that is why label reading matters so much for this herb.

What the research says, in careful terms

The NIH consumer sheet opens with a caution: the health effects of ashwagandha extracts have not been thoroughly studied. Here is what it and the NCCIH say.

• Stress and anxiety. The NIH says ashwagandha extracts might help reduce stress and anxiety. In several studies, people who took it for 6 to 8 weeks reported feeling less stress and anxiety, as well as less fatigue and sleeplessness, and ashwagandha lowered stress hormone levels. The NCCIH says some preparations may be effective for stress, while evidence on anxiety is unclear.
• Sleep. The NIH says results from a few small studies suggest ashwagandha extracts might improve sleep, but the overall benefits were small. The NCCIH says some preparations may be effective for insomnia.
• Other uses. The NCCIH says there is some limited evidence that taking ashwagandha for 2 to 4 months may increase testosterone levels and sperm quality, and that there is not enough evidence to say whether it helps with asthma, athletic performance, cognitive function, diabetes, menopause or female infertility. It also says there is not enough high-quality evidence to support its use for COVID-19.

The NIH health professional sheet adds the limits of this research: the studies were mostly small and short, they used many different preparations (different parts of the plant, different extraction and standardisation methods) and different doses, and most were conducted as part of a traditional medical system, so the effect of ashwagandha as a supplement outside that approach remains unclear. It says that because of this it is difficult to identify specific extracts or recommended amounts.

For a label reader this is the most important finding. The research is on specific extracts at specific doses. A product that does not tell you which extract and how much is not comparable to any of it.

Safety: this is the section to read twice

Ashwagandha is a herb with real effects, and safety deserves a full section. Both the NIH and the NCCIH are direct.

• Duration. The NIH says no safety concerns were seen in the studies for use of up to about 3 months, but it is not clear whether ashwagandha is safe for longer periods. The NCCIH says it may be safe in the short term (up to 3 months) and that there is not enough information on long-term safety.
• Common side effects. Usually mild: upset stomach, loose stools, nausea and drowsiness, according to the NIH. The NCCIH adds diarrhoea and vomiting.
• Liver. The NIH says extracts have been linked to liver injury in some people. The NCCIH says it is rare, but there have been a number of cases linking liver injury to ashwagandha supplements. The Australian Therapeutic Goods Administration (TGA) issued a safety advisory in 2024 about gastrointestinal symptoms and very rare cases of liver injury. It advises stopping the product and seeking medical advice if you have symptoms such as yellowing of the skin or eyes, dark urine, nausea, vomiting, unusual tiredness, weakness, stomach pain or loss of appetite, and says people who have or have had liver problems should avoid products containing Withania somnifera.
• Thyroid. The NIH says a few studies show ashwagandha may affect how the thyroid works and might interact with thyroid medication. The NCCIH says it is not recommended for people with autoimmune or thyroid disorders.
• Other medicines. The NIH says ashwagandha might also interact with diabetes and blood pressure medications, sedatives and medicines that suppress the immune system. The NCCIH also lists anti-seizure medicines.
• Pregnancy and breastfeeding. The NIH says it may not be safe in pregnancy or breastfeeding. The NCCIH says it should be avoided during pregnancy and not used while breastfeeding. The NIH health professional sheet notes that Denmark banned its use in 2023 and that the French agency ANSES recommended against its use in certain groups in 2024.
• Surgery and hormone-sensitive cancer. The NCCIH says it is not recommended for people who are about to have surgery, and that people with hormone-sensitive prostate cancer should avoid it.

The practical message: speak to a doctor before using ashwagandha, especially if you take any regular medicine, have a thyroid, liver, or autoimmune condition, are pregnant or breastfeeding, or have surgery planned. If you are buying for someone else, the same applies. Do not give it to a child unless a health care provider recommends it.

What to check on an ashwagandha label

1. The plant part

Look for "root", "leaf" or "root and leaf". The research the NIH describes includes extracts from root alone and from root plus leaf. These are not the same product. A label that says only "ashwagandha extract" does not tell you which. A label that says "ashwagandha powder" is a plain ground plant and not a concentrated extract. Choose based on what the label states, not on a guess.

2. Powder or extract

Powder is the ground plant. An extract is a concentrated preparation made using a solvent such as water or alcohol. The NIH health professional sheet describes studies using extracts made with different extraction processes. If the label does not say whether the product is powder or extract, or gives only a "ratio" with no explanation, you cannot compare it to anything.

3. Standardisation

Some extracts are standardised, which means the maker guarantees a minimum amount of a marker compound. For ashwagandha the marker is usually withanolides, which the NIH health professional sheet describes as steroidal lactones, believed to be responsible for many of ashwagandha's proposed effects while other components may also be involved. The sheet describes trial extracts standardised to different withanolide levels, so the figure on one label is not interchangeable with another.

What this means for you: look for whether the label states the withanolide percentage or amount, and how it was measured. A stated figure is more transparent than none. Do not read a higher percentage as automatically better. Without evidence for that figure at that dose, it is only a number.

4. Milligrams of extract per serving

Find the amount of ashwagandha extract in one serving, then the servings per day. The NIH consumer sheet reports that in some studies ashwagandha appeared more effective at doses of 500 to 600 mg a day compared with lower doses for stress and anxiety, and at 600 mg a day or more for at least 8 weeks for sleep. Those are descriptions of what studies used, not advice for you. The NIH health professional sheet also notes that the studies used various preparations and doses and that recommended amounts are difficult to give. Use these numbers only to check that the dose on a label is in the range that studies explored, and ask a health professional what is right for you.

Watch the serving size. If one capsule has a low amount and the serving is three capsules, work out the daily total. If the label says "proprietary blend", you cannot see the amount of ashwagandha at all.

5. Other ingredients and combinations

Many products combine ashwagandha with other herbs, melatonin, magnesium, vitamins or caffeine-containing ingredients. Each added ingredient brings its own interactions. The NIH says ashwagandha might interact with sedatives, and a product that also adds a sleep ingredient raises the same concern. A single-ingredient product is easier to understand and to discuss with a doctor.

6. Warnings on the label

A responsible label includes cautions for pregnancy, breastfeeding, thyroid conditions, liver problems and medicines. If a label has no cautions at all, it is less careful than the sources above.

7. Claims

Be careful with promises about cortisol, testosterone, weight, "adaptogen" benefits or "clinically proven" results. The research is mixed and often small, and varies with the extract. Prefer labels that describe the ingredient and the amount and leave health outcomes to your doctor.

The Right Supplements method applied to ashwagandha

Right Supplements, India's supplement comparison platform, compares products on five factors with fixed weights: Ingredient Quality (30), Clinical Evidence (20), Dosage Accuracy (20), Third-Party Testing (15) and Value (15). Here is how each applies to ashwagandha. This is the method only, and no product is scored. The general framework is in our guide on how to compare supplements before you buy in India.

Ingredient quality

Plant part named, powder or extract stated, standardisation described, no hidden blend, short ingredient list. For a herb, clear identification matters more than for most nutrients, because the plant itself varies. The botanical name Withania somnifera on the label is a good sign.

Clinical evidence

Check whether the extract on the label matches the kind of extract studied, and whether the dose on the label is in the range the studies used. Remember the NIH point that studies used many different preparations, so evidence for one extract does not automatically apply to another.

Dosage accuracy

Milligrams of extract per serving, servings per day and the standardised marker if stated. Compare like with like: powder against powder, extract against extract.

Third-party testing

For herbal products, independent testing is especially relevant because what is in the capsule comes from a plant. The NIH explains that independent organisations such as ConsumerLab.com, NSF International and U.S. Pharmacopeia offer testing and allow products that pass to display a seal, with the note that seals do not guarantee a product is safe or effective. Look for a named test or certificate that you can verify, and a batch number. Given the safety reports above, do not skip this step.

Value

Compare cost per day for the same type of extract and a comparable daily amount. A low price per bottle can hide a low amount of extract per capsule.

A label checklist for ashwagandha

• The label names Withania somnifera and the plant part (root, leaf or both).
• It says whether the product is powder or extract.
• If standardised, it states the marker (such as withanolides) and the amount.
• Milligrams of extract per serving and servings per day are clear.
• No hidden proprietary blend and no unexplained add-ons.
• Cautions are printed for pregnancy, breastfeeding, thyroid, liver and medicines.
• A named independent test or certificate can be verified.
• Claims stay modest.
• You know your cost per day.
• You have spoken to a doctor, especially if you take regular medicines or have a thyroid, liver or autoimmune condition.

Common mistakes

Assuming a traditional herb needs no checks

Traditional use is long, but the NIH and NCCIH still describe interactions and liver and thyroid concerns.

Buying on the percentage alone

A higher withanolide percentage is not proof of a better product. Compare the extract and dose against what has been studied.

Taking it for months without review

The NIH and NCCIH say safety beyond about 3 months is not established. Review use with a health professional.

Ignoring symptoms

If you develop symptoms such as yellowing of the skin or eyes, dark urine, persistent nausea or unusual tiredness, the TGA advises stopping and seeking medical advice.

Mixing with other sedating or thyroid-related products

The NIH lists sedatives and thyroid medications among possible interactions. Tell your doctor and pharmacist.

Key takeaways

• Ashwagandha is a traditional herb sold as root, leaf or root-and-leaf extracts. Research is on specific extracts and doses, so the label must say what you are getting.
• Research on stress and sleep is promising but mostly small and short, and the NCCIH says evidence on anxiety is unclear.
• Safety information is serious: possible liver injury, thyroid effects, medicine interactions, and avoidance in pregnancy and breastfeeding. Speak to a doctor first.
• Check plant part, powder or extract, standardisation, milligrams per serving, add-ons and printed cautions.
• Look for named independent testing you can verify.
• Compare cost per day like for like.

Frequently asked questions

What is ashwagandha?

Ashwagandha (Withania somnifera) is a plant used in traditional Ayurvedic and Unani medicine. The NIH says supplements usually contain extracts from the roots or from the roots and leaves.

Does ashwagandha work for stress and sleep?

The NIH says extracts might help reduce stress and anxiety and might improve sleep, but the research is limited and the sleep benefits were small. The NCCIH says evidence on anxiety is unclear. Studies used many different preparations and doses.

Is ashwagandha safe?

The NIH and NCCIH say it appears safe for short-term use, up to about 3 months, but long-term safety is not known. Liver injury has been reported in rare cases. Speak to a doctor first.

Who should avoid ashwagandha?

The NIH says it may not be safe in pregnancy or breastfeeding or for people with prostate cancer. The NCCIH says it is not recommended before surgery or for people with autoimmune or thyroid disorders. Ask a doctor about your own situation.

Can ashwagandha interact with medicines?

Yes. The NIH lists thyroid, diabetes and blood pressure medicines, sedatives and immune-suppressing medicines. The NCCIH also lists anti-seizure medicines.

What does 'standardised to withanolides' mean?

The maker states a minimum amount of withanolides, a group of plant compounds, in the extract. Trials used extracts standardised to different levels, so one label's figure is not directly comparable with another's.

What should I check on an ashwagandha label?

The plant part (root, leaf or both), whether it is powder or extract, standardisation, milligrams per serving, any add-ons or blends, printed cautions and a named independent test.

Is this guide medical advice?

No. It is general information for reading labels and comparing products.

Sources

• NIH Office of Dietary Supplements: Ashwagandha (Consumer)
• NIH Office of Dietary Supplements: Ashwagandha (Health Professional)
• NCCIH: Ashwagandha: Usefulness and Safety
• Australian TGA: Medicines containing Withania somnifera (safety advisory, 2024)
• NIH Office of Dietary Supplements: Dietary Supplements: What You Need to Know (Consumer)

This guide is general information, not medical advice. Supplements can interact with medicines and are not suitable for everyone. Please speak to your doctor before starting anything new.