The truth about ashwagandha’s possible health benefits – and its risks

Depending on who you follow on social media, you may have come across talk of a little-known herb called ashwagandha over the past year.

Celebrities including Meghan Markle, Gwyneth Paltrow and Jennifer Aniston are reported to use ashwagandha for its calming effects. Ashwagandha has been trending on social media, with data showing #ashwagandha had more than 670 million views on TikTok in 2024.

Scientifically known as Withania somnifera, ashwagandha is a common herb used for thousands of years in Ayurvedic medicine – an ancient Indian system of healing based on the belief that health and wellness depend on a balance between the body, mind and spirit.

Ayurveda emphasises a holistic approach to health using natural treatments, such as herbal remedies, dietary changes, physical therapy, meditation and yoga.

But beyond the social media buzz, what does science say about this herb’s benefits?

Ashwagandha root has been used in traditional medicine as an adaptogen. This means it could help people become more resilient to various types of stress, whether biological, physical, or chemical.

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The strongest evidence available for ashwagandha is as a stress and anxiety reliever. A review looking at several small studies showed that ashwagandha can significantly reduce levels of perceived stress and anxiety in people. This may be partly due to its regulating effect on stress hormones such as cortisol.

Ashwagandha is also known for its ability to improve sleep quality. The “somnifera” part of its scientific name, meaning “sleep-inducing”, hints at its effects.

Some trials show it can help people fall asleep faster and enjoy deeper, more restful sleep, thus boosting energy levels. This may be beneficial for people suffering from insomnia. But there is no evidence showing whether it is better than taking sleeping tablets.

Recently, this herb has been associated with other benefits. The Sanskrit word “ashwagandha” means “the smell of a horse,” symbolising its ability to give the strength and stamina of a horse. Athletes and fitness enthusiasts may benefit from ashwagandha’s ability to enhance physical performance. Some research indicates that ashwagandha can improve strength, muscle mass and oxygen use during exercise.

For men, ashwagandha has been shown in some small studies to boost testosterone levels and improve fertility by increasing sperm count and motility. This may be linked to dehydroepiandrosterone (DHEA) – a sex hormone that your body naturally produces. DHEA is used to make other hormones, such as testosterone. This means men with prostate cancer sensitive to testosterone should avoid using this herb.

Ashwagandha has been linked to improved cognitive function, such as better memory and focus. Small studies, involving older people who have some cognitive impairment, suggest that ashwagandha may help to reduce oxidative stress – harmful molecules called free radicals that can damage cells in the body – and inflammation, which can negatively affect memory and thinking processes.

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There are also ongoing clinical trials investigating whether ashwagandha may be effective in treating long COVID symptoms such as fatigue and cognitive dysfunction, having trouble with mental tasks such as thinking, remembering and making decisions – but there’s no robust evidence yet.

Ashwagandha is rich in phytochemicals, including withanolides. Withanolides are steroidal lactones – they are structurally similar to steroids, with a lactone ring in their chemical structure – that are thought to help cells absorb glucose from the bloodstream. This can lower blood sugar in both healthy people and those with diabetes, although larger studies need to be done. In animal studies, withanolides show anti-inflammatory activity.

While ashwagandha may offer potential health benefits, it also has numerous risks and side effects. The long-term safety of ashwagandha is not well-documented. Most studies have focused on short-term use, typically up to three months, but the benefits may take some weeks or months to appear. The most common side effects are mild stomach upsets and nausea.

Its use is not advised in people with some pre-existing health conditions, such as liver disease. Although rare, there have been reports of liver problems, including severe liver failure, associated with ashwagandha use.

Ashwagandha may stimulate the immune system, potentially causing flare-ups for people with autoimmune conditions such as multiple sclerosis and rheumatoid arthritis.

It’s also possible that ashwagandha may interact with some medications, such as immunosuppressants, sedatives and thyroid hormone medications. Research suggests that ashwagandha may influence thyroid function, particularly by increasing thyroid hormone levels. It may also interact with thyroid medications, such as levothyroxine, possibly leading to overmedication.

Pregnant and breastfeeding women are advised to avoid ashwagandha, especially at higher doses. The herb may be linked to miscarriages and, although there’s conflicting evidence, it’s best to be cautious.

Ashwagandha holds promise, then, as a stress reliever, sleep aid and even an energy booster. With growing interest and a large body of anecdotal evidence, it’s no surprise that it’s become a favourite among wellness enthusiasts. However, scientific research is still developing and more extensive clinical trials are needed to confirm the benefits, side effects and determine the safest, most effective doses.

If you’re considering incorporating ashwagandha into your routine, especially for long-term use, do consult a healthcare professional first, especially if you have pre-existing health conditions or are taking other medications.

Dipa Kamdar is a Senior Lecturer in Pharmacy Practice at Kingston University.

This article is republished from The Conversation under a Creative Commons license. Read the original article.