Ashwagandha is a small evergreen shrub that grows in Asia and Africa.
Its botanical name is Withania somnifera
The shrub's roots and berries are used to make an Ayurvedic medicine (the traditional medical system of India).
Ashwagandha is available in capsules and powders that can be mixed into soft foods (such as yogurt or oatmeal).
The root, root powder, and standardized withanolide extracts are used in a wide range of doses. (Unlike with prescription medications, there is often little—or conflicting—evidence about the best dose of supplements, including ashwagandha.)
Some dietary supplements used to improve sleep or treat stress contain ashwagandha among other ingredients.
(See also Overview of Dietary Supplements.)
Claims for Ashwagandha
Advocates believe that ashwagandha is an adaptogen. This herbal medicine term means that this substance is thought to help the body respond to mental and physical stress and to restore normal emotional and physical body function.
In 2020 and 2021, some people began using ashwagandha to diminish the harmful effects of COVID-19, although there is no evidence to support that use.
The long list of other benefits claimed for ashwagandha includes
Reducing symptoms of stress that may lead to anxiety and depression
Increasing fertility in men
Helping people with insomnia sleep
Increasing muscle mass, strength, endurance, and energy
Reducing inflammation (for example, to help prevent cartilage damage caused by osteoarthritis)
Lowering cholesterol and triglyceride levels
Lowering blood pressure
Improving brain function (including memory)
Reducing blood sugar levels in people with diabetes
Killing cancer cells
Reducing weight gain associated with cortisol (a hormone released in response to stress)
Evidence for Ashwagandha
Any single compound, including ashwagandha, is highly unlikely to have such a broad range of health benefits. There is insufficient evidence that ashwagandha reduces stress, improves sleep, or is effective for treating any disease
Ashwagandha in a combination supplement product demonstrated the potential to relieve symptoms of osteoarthritis, but it is unclear if the benefit was due to ashwagandha or one of the other ingredients or the combination.
One study reported that people who took ashwagandha had significant improvement in muscle strength, bench-press power, squats, and recovery scores.
Larger studies in people are needed to confirm the benefits of ashwagandha.
Side Effects of Ashwagandha
Side effects of ashwagandha may include diarrhea, headache, sedation, or nausea. Liver problems may occur.
Ashwagandha may increase testosterone levels.
Ashwagandha should not be used during pregnancy or breastfeeding.
Drug Interactions with Ashwagandha
Ashwagandha might lower blood sugar levels and thus make it unsafe to use with antihyperglycemic (glucose-lowering) medications (by lowering blood sugar too much).
Because of its potential to lower blood pressure, ashwagandha might not be safe in people who take medications to treat high blood pressure.
Ashwagandha may increase thyroid hormone levels, so doctors carefully monitor thyroid function by ordering blood tests for anyone who takes thyroid hormones and ashwagandha at the same time.
Recommendations for Ashwagandha
No beneficial health effects of ashwagandha have been confirmed in high-quality studies in people.
Use of ashwagandha is not recommended because there are no confirmed benefits to outweigh the possibility of negative side effects.
Ashwagandha is probably safe for most people; however,
Pregnant women, people with stomach ulcers, and those with liver disease should avoid ashwagandha.
Women who are breastfeeding and people who take certain medications (including medications to suppress the immune system, lower blood sugar, lower blood pressure, and some sedatives) should talk to their doctor before taking ashwagandha.
People taking thyroid hormones should also talk to their doctor about taking ashwagandha because blood levels of thyroid hormones may be affected.
