Home / Best ashwagandha supplement: buying guide

Best ashwagandha supplement: buying guide

Updated November 2026 · How we review

The ashwagandha aisle is crowded, and most of the difference between products comes down to one thing: which extract is inside and how much of it. Here's how to match a label to what was actually used in research.

Quick picks by extract type

• Most researched overall: KSM-66 (root only). Used in the largest share of stress and sleep trials. A good default if you want a product that lines up with the research.
• Lower dose, evening use: Sensoril or Shoden (root and leaf). More concentrated extracts studied at smaller doses; Shoden was used at 120 mg a day in a sleep study.
• Budget: plain root powder. Cheapest per gram, but much less concentrated and harder to match to study doses.
• Usually skip: low-dose gummies and "proprietary blends." If the label won't tell you how many milligrams of which extract you're getting, you can't compare it to anything.

We name extract types rather than individual brands because we haven't lab-tested specific products. Use the checklist below to compare the brands you find.

Ashwagandha extracts compared

For a deeper look at the two most common extracts, see KSM-66 vs Sensoril.

How we evaluate an ashwagandha product

1. Named extract or standardization. The label should say KSM-66, Sensoril, Shoden, or give a withanolide percentage.
2. Dose you can compare. Milligrams of extract per serving, clearly stated, in the range used in studies.
3. Plant part. Root, or root and leaf. Studies used both, but they aren't interchangeable.
4. Third-party testing. A USP Verified or NSF seal, or a published certificate of analysis. What the seals mean.
5. Sensible extras. Black pepper extract or a few vitamins are fine; long "stress blends" dilute the main ingredient.
6. No disease claims. Supplements can't legally claim to treat anxiety, insomnia or thyroid problems. Products that do are a red flag.
7. Cost per effective dose. Divide the price by the number of days a bottle lasts at the studied dose, not by the number of capsules.

You can run any product through our six-question label checker.

Capsules, gummies or powder?

Capsules are the easiest way to get a known dose of a branded extract. Gummies are convenient but often contain much less extract and added sugar, so check the milligrams. Powder is the cheapest and mixes into drinks, but it's usually unstandardized root. More in capsules vs gummies vs powders.

What the research says

Several small randomized trials, most of them run in India, found that ashwagandha extracts reduced self-reported stress and anxiety and lowered cortisol compared with placebo. Several studies saw larger benefits at 500 to 600 mg a day than at lower doses. A handful of sleep trials found modest improvements in sleep quality and time to fall asleep, especially in people with insomnia. Most studies lasted 6 to 12 weeks, so long-term effects aren't well known. Read our full ashwagandha review.

Who should avoid it

Talk to a doctor first if you are pregnant or breastfeeding, have a thyroid or liver condition, have prostate cancer, or take thyroid, diabetes, blood pressure, sedative or immune-suppressing medicines. Rare cases of liver injury have been reported, and ashwagandha can raise thyroid hormone levels. Common side effects are mild: upset stomach, loose stools and drowsiness. See safety and interactions.

Frequently asked questions

Which ashwagandha extract is best?

There's no single best. KSM-66 (root only) has the most published studies on stress and was used in several sleep trials. Sensoril and Shoden (root and leaf) are more concentrated, so studies used smaller doses. Pick the extract whose studied dose matches what's on the label.

How much ashwagandha did studies use?

For stress and anxiety, studies used roughly 240 to 1,250 mg a day of extract, with several finding better results at 500 to 600 mg a day. Sleep studies used 250 to 600 mg a day of KSM-66, or 120 mg a day of Shoden. Follow the product label and your doctor's advice.

Are ashwagandha gummies as good as capsules?

Often not. Many gummies contain far less extract than the doses used in studies, don't name a branded extract, and add sugar. Check the milligrams per serving before you buy.

How long does ashwagandha take to work?

Most studies ran 6 to 12 weeks, and the sleep benefits appeared most clearly at 8 weeks or longer. Safety data mostly cover use up to about 3 months.

Who should not take ashwagandha?

People who are pregnant or breastfeeding, people with thyroid conditions or liver disease, people with prostate cancer, and anyone taking thyroid, diabetes, blood pressure, sedative or immune-suppressing medicines should talk to a doctor first.

Sources

• NIH Office of Dietary Supplements: Ashwagandha fact sheet for health professionals
• NIH Office of Dietary Supplements: Ashwagandha fact sheet for consumers
• NIH National Center for Complementary and Integrative Health: Ashwagandha