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“There are a lot of scientific research studies on it,” says Yufang Lin, an integrative medicine specialist at the Cleveland Clinic. But “the studies have limited data.”
People often take ashwagandha (Withania somnifera) in the form of powders, capsules, tablets, liquid drops, or gummies containing extracts of the plant’s roots to help with stress or sleep. And research does show that the supplement can alleviate perceived stress and anxiety, as well as reduce levels of the stress hormone cortisol, compared with placebo treatments. In one study, subjects rated their stress 44 percent lower, on average, after taking ashwagandha for 60 days. Some studies also suggest it can help people fall asleep a few minutes faster, sleep up to 25 minutes longer and wake up in the night up to 12 minutes less, with greater gains for insomniacs.
Experts say this could make the herb useful for those experiencing anxious, jumpy types of stress, like a student dreading an exam. Margaret Harris, a nutrition researcher at the University of Colorado in Colorado Springs, has studied the effects of ashwagandha supplementation on college students and has taken the supplement herself.
“After about nine to 10 days, the people in the intervention group started saying, ‘You know, I feel like I can … accomplish everything I want to accomplish today,’” Harris says, recalling one of her studies.
In addition to studies of ashwagandha’s impacts on stress and anxiety, a small pool of research reports other benefits in people such as reducing blood sugar, enhancing physical performance and muscle strength, boosting cognitive functions like memory and focus, and increasing testosterone, sperm count and sperm health in men. Ashwagandha may derive some beneficial properties in part from compounds called withanolides, which have anti-inflammatory and antioxidant properties.
And as far as experts know, ashwagandha doesn’t dull emotions or render oral birth control less effective, as some TikTok creators have said — though experts note there are occasional cases of users feeling too sedated, or having stomach pain or loose stool.
But the limited number of randomized, controlled studies investigating each touted use — and the limited number of subjects in each study — leaves ashwagandha’s confirmed benefits unclear.
“You’ll see with a lot of the studies that there are dozens of people [studied] as opposed to hundreds or thousands of people,” says Denise Millstine, an integrative medicine specialist at the Mayo Clinic in Scottsdale, Ariz. Making more conclusive statements about what ashwagandha can do, she says, would require more studies with “enough subjects involved to demonstrate power and not just chance.”
Even the more plentiful studies into ashwagandha’s stress and sleep benefits have had small sample sizes and lasted no more than three months, meaning experts don’t know the impacts of sustained dosage over longer periods. Experimental setups have also varied widely in dosage and type of preparation given to participants, making it difficult to know which amounts of which extracts are best.
Most studies have also examined ashwagandha in the context of Ayurvedic medicine, an ancient Indian practice based on holistic healing. Millstine notes that while traditional botanical medicine practices like Ayurveda combine ashwagandha with other relaxants like chamomile, lemon balm and rhodiola, many people today take the herb by itself, so future research may benefit from comparing the two approaches
None of this necessarily means the plant isn’t helpful, Millstine says — only that more research is needed. “There’s a lot of wisdom in tradition, so that shouldn’t be thrown out the window just because there [is] a lack of randomized controlled trials.”
That’s especially true given that ashwagandha is generally safe, she adds. While certain groups should steer clear — notably pregnant people, since high doses can lead to miscarriage — for most people, “a lot of the studies are showing that it doesn’t really pose a lot of side effects,” Harris says.
Just keep in mind the plant isn’t a miracle cure-all, experts say. It may take more than a supplement to ease your mind if you have severe anxiety, or to help you sleep if you’re scrolling social media late at night. In Lin’s practice, she works with patients to develop better sleep, diet, mental health and exercise habits to manage stress and fatigue (SN: 2/21/23). “Ashwagandha may be a piece of the puzzle,” Lin says. But “you have to use it in [the] context of how a patient’s doing overall.”