What is ashwagandha?

A mainstay of Ayurvedic medicine, ashwagandha is also known as Indian ginseng or Indian winter cherry. It’s made from a shrub found in India and Africa that is formulated into teas, powders, and capsules. 

Ashwagandha is considered an adaptogen—a plant substance that helps regulate cortisol, which, in turn, can reduce the body’s stress response. Too many stress hormones have a harmful effect on the body over time leading to inflammation, anxiety, lower immunity, and depression.

What are the benefits of ashwagandha?

The most solid research around ashwagandha shows that it can: 

• Reduce your body’s stress response
• Help ease anxiety
• Improve brain function, including memory
• Reduce inflammation

Does ashwagandha improve sleep?

Despite how commonly the supplement is used for sleep, there’s not a lot of evidence to show that it helps. At best, the studies on the subject “are a little inconsistent,” says Dr. Jennifer Martin, a psychologist and immediate past president of the American Academy of Sleep Medicine. 

One 2019 study found that a twice-daily dose of ashwagandha led to a reduction in anxiety and improved sleep. Another study of just 50 adults found that taking ashwagandha every day for 12 weeks improved sleep.

If stress or mild anxiety is getting in between you and sleep, ashwagandha could be helpful in reducing anxiety, which may facilitate a better night’s rest—at least according to this limited research.

Martin, however, does not recommend taking ashwagandha or any other supplements, like melatonin, for sleep issues. Instead, she says, people struggling with sleep should take steps to get their bedroom and sleep hygiene in order. 

“There is nothing in Ayurvedic medicine that will fix bad habits around your sleep,” she says. Your goal should be to work toward a consistent sleep schedule and create a relaxing sleep environment.  

The best way to use supplements is to enhance a good nighttime routine, Dr. Ana Krieger, medical director of the Center for Sleep Medicine at Weill Cornell Medicine and NewYork-Presbyterian previously told Fortune. 

Good sleep hygiene means ensuring your bedroom is dark, quiet, and cool; going to bed and waking up around the same time; cutting back on exposure to bright light before bed, and “[learning] how to reduce stressors and underlying anxieties that may be affecting sleep,” Krieger said.

“If you’re really struggling and you can’t fix it on your own, reach out to your health care provider for help,” says Martin.

How much ashwagandha is safe to take?

Up to about 500 mg per day is considered safe, according to the Cleveland Clinic, but the dosage depends on what form you’re taking it in and what you’re taking it for. It’s best to talk to your doctor about the ideal dose for you. 

Additionally, studies have shown that the contents of some supplements may be much higher than the label states, or they may contain other harmful ingredients. To be safe, Krieger suggests choosing only supplements that are certified by NSF International (formerly the National Sanitation Foundation), a third-party agency that verifies the purity of ingredients in supplements. 

What are the side effects of ashwagandha?

Though ashwagandha is generally safe for most adults, according the NIH, it can cause side effects including: 

• Diarrhea
• Drowsiness
• Headache
• Stomach upset

Some people can have liver problems when taking ashwagandha, especially if they’re taking it with other medications metabolized in the liver. 

Women who are pregnant or breastfeeding should avoid taking ashwagandha.

As with all supplements, it’s best to check with your doctor before taking ashwagandha. There could be drug interactions with other medications you’re on and your doctor can help you sidestep potential problems.