Ashwagandha

Studies in people

• Benefit

  Men's hormone levels²

  In men, ashwagandha root extract significantly raised testosterone levels in some studies.

• Concern

  Liver injury risk³

  In people, ashwagandha side effects were rare, though a few cases of liver injury were reported.

• Concern

  Supplement side effects⁴

  Some people taking ashwagandha have reported liver damage, and it may affect hormones and pregnancy.

• Benefit

  Weight loss and food cravings⁵

  In people, ashwagandha may help weight loss by lowering stress, cortisol and food cravings.

• Open question

  Exercise endurance⁶

  Ashwagandha supplements may help healthy adults and athletes use oxygen better during exercise, but scientists say more research is needed.

• Benefit

  Memory and focus⁸

  In healthy young adults, ashwagandha improved some memory, attention and reaction-time scores and reduced tension and fatigue.

• Open question

  Muscle strength gains⁹

  In men doing weight training, ashwagandha led to bigger strength gains than a dummy pill.

• Open question

  Muscle strength and size¹⁰

  In young men doing weights, ashwagandha led to bigger gains in strength and muscle size than a dummy pill.

• Benefit

  Weight and stress¹¹

  In people, ashwagandha root extract led to lower weight, less stress and fewer food cravings than a placebo.

• Benefit

  Stress hormones in athletes¹⁴

  In female athletes, ashwagandha kept cortisol steady while placebo rose; in males, it kept cortisone steady.

• Benefit

  Stress and weight¹⁵

  In people under chronic stress, ashwagandha improved stress scores, food cravings and body weight.

• No harm found

  Body fat and blood fats¹⁶

  In healthy young men doing interval training, ashwagandha did not change body composition or blood fat levels.

• Benefit

  Recovery and sleep in female athletes¹⁷

  In female footballers, 600 mg a day of ashwagandha root extract for 28 days may improve perceived recovery and sleep quality.

Animal and lab studies only

• Open question

  Fat tissue inflammation²⁰

  In lab studies, ashwagandha taken by people changed fat tissue genes tied to inflammation and fat burning.

• Open question

  Liver injury reports²¹

  In lab studies, a 70% ethanol ashwagandha root extract changed a liver enzyme that processes drugs.

Study type not stated

• Open question

  Herb research gaps¹⁸

  Scientists still need thorough studies on ashwagandha's safety and how well it works before using it more widely.

• Benefit

  Stress and sleep¹⁹

  Ashwagandha may help with stress and sleep, but scientists do not yet know for sure.

Single cases of misuse or overdose

One person or one incident, such as an accidental overdose or a mistake in a kitchen or factory. They are real, but a single case does not show what happens at normal amounts, so the signal does not count them.

• Liver injury from supplements¹³

  A woman got jaundice and nausea after taking ashwagandha, and her liver biopsy showed injury.

How it’s made and used

• What the body does with it⁷

  In older adults, small amounts of ashwagandha withanolides appeared in urine after swallowing the extract.

• How much the body absorbs¹²

  In people, a low-dose ashwagandha extract reached higher levels in the blood than two higher-dose products.

The signal at the top counts the findings in people and in animal and lab studies. A concern in studies of people outranks animal and lab studies, and “No concerns” needs at least one finding in people. When most findings in people point one way, the page leans that way (“Mostly”), and every finding is still shown. Findings whose study type is not stated are shown but not counted. This page is a reference, not medical advice. It describes what regulators and published research say. Talk to a doctor or dietitian about your own diet.