Ashwagandha — the common name for an herb also referred to as Indian ginseng or winter cherry — is a Sanskrit word to describe the smell of its root, which is "like a horse."

Used in traditional Ayurvedic and Unani medicine systems of India, the National Institute for Complementary and Integrative Health (NICIH) says there is research showing that some preparations of the herb may be useful for relieving insomnia and stress.

For example, a 2021 study published in the journal PlosOne indicated that ashwagandha may be effective for easing insomnia, which can be stress-related. And limited evidence shows it might increase the release of testosterone, increasing free testosterone levels and sperm quality if it's taken for two to four months.

But the NICIH says there isn't solid evidence to know if it can help with asthma, athletic performance, cognition, diabetes, menopause, or female infertility.

Is it safe to try?

The NIH Office of Dietary Supplements says that in studies "ashwagandha has been well tolerated by participants for up to about three months. Common side effects are mild and include stomach upset, loose stools, nausea, and drowsiness."

It's also been found that overly large doses can cause vomiting and gastrointestinal upset.

There are no long-term studies to evaluate if the herb is safe when used for many months or years. We do know that because it can increase testosterone levels, men with hormone-sensitive prostate cancer should avoid ashwagandha.