Ashwagandha: Can it reduce stress and anxiety?

Stress and anxiety are common in modern societies. Both can squeeze the joy out of life and, over the years, impact your health.

For instance, long-term stress is associated with an increased risk of high blood pressure, cardiovascular disease, obesity, and other health issues.

People are keen to find ways to ease their stress, and many turn to supplements.

One supplement that proponents claim can relieve stress and anxiety is ashwagandha. Some also point to other health benefits.

Here, we’ll examine the evidence and ask whether it might help.

What is ashwagandha?

Ashwagandha is a member of the nightshade family. It’s an evergreen shrub, and it’s native to India, the Middle East, and some parts of Africa.

Used in traditional Indian medicine for thousands of years, ashwagandha is now widely available as a supplement.

Interestingly, it gets its name from its odor — "ashwagandha" means “horse smell” in Sanskrit.

Traditionally, the shrub has been used in an impressive array of situations. It’s considered an aphrodisiac, sedative, and narcotic, as well as an effective treatment for snakebites, leprosy, and smallpox.

In this article, we’ll zero in on stress and anxiety. And because of the links between stress and sleep, we’ll touch on that, too.

Stress and anxiety

Among the many health claims attached to ashwagandha, its ability to relieve stress and anxiety is perhaps the most common.

And a number of studies have investigated whether ashwagandha has this effect. So, what’s the verdict?

A review of animal and human studies published in 2021 concludes that ashwagandha “exhibited noteworthy anti-stress and antianxiety activity in animal and human studies.” 

But overall, the authors call for more research. And, just to forewarn you, that’s a phrase you'll read quite a bit today.

As an example of the studies they reviewed, one recruited 60 participants and ran for 8 weeks. The participants were generally healthy but had moderate to high levels of perceived stress.

The trial was a randomized, double-blind, placebo-controlled study, which scientists consider the “gold standard” of research.

The scientists split the participants into three groups, and all the participants took two supplements every day. 

One group took high-dose ashwagandha supplements, one group took a lower dosage, and the third group took placebo supplements.

At the end of the study, participants taking either dosage of ashwagandha had lower perceived stress and lower levels of the stress hormone cortisol in their blood. 

Those in the ashwagandha groups also reported better sleep than those in the placebo group — more on that later.

Although the results are encouraging, the scientists call for longer trials to gauge whether the effects last. They also point out that studies with a broader range of participants would be useful.

A 2022 review of 12 randomized controlled studies, including more than 1,000 participants, also concluded that ashwagandha reduced both stress and anxiety, compared with a placebo. 

However, the authors caution that the “certainty of the evidence was low.” Consequently, they too call for more research to “firmly establish the clinical efficacy of the plant.”

Overall, the evidence isn’t super strong, but it’s hopeful. So, if ashwagandha does help relieve stress and anxiety, how might it work?

How might ashwagandha work?

To understand how ashwagandha could reduce stress, let’s take a quick tour of the hypothalamic-pituitary-adrenal (HPA) axis.

In short, the HPA axis is a three-way conversation between the hypothalamus and pituitary gland in your brain and your adrenal glands, which sit on top of your kidneys.

This dialogue helps regulate a range of bodily processes, like your mood and emotions, your immune system, and your stress responses. 

In one study, researchers showed that ashwagandha was linked to decreased levels of cortisol and dehydroepiandrosterone-sulfate in the morning, compared with a placebo. 

Levels of these hormones, which are released from your adrenal glands, increase following a stress response. 

So, the authors of the paper suggest that ashwagandha might influence the HPA axis to reduce levels of these hormones. This might, in turn, reduce the stress response.

Alternately, the authors theorize that ashwagandha might work by reducing inflammation or oxidative stress, both of which increase during psychological stress. 

However, there’s little proof that ashwagandha affects inflammation or oxidative stress in humans. So far, the existing evidence mostly comes from lab and animal studies.

Overall, unraveling precisely how ashwagandha works will be challenging.

It contains a whole host of compounds, including the mystical-sounding withaferin A, viscosalactone B, shikimic acid, and jaborosalactone D. Understanding what role, if any, these are playing will take some digging. 

And until researchers go any farther down this fascinating rabbit hole, we won’t know for certain that ashwagandha works to reduce stress or anxiety. 

Things look hopeful, but as you’ve already gathered, we need more research.

Ashwagandha and sleep

There’s a two-way street between stress or anxiety and sleep. Not getting enough sleep increases the risk of feeling stressed or anxious, and feeling stressed or anxious can interfere with sleep.

So, might ashwagandha reduce stress because it improves sleep? 

The Latin name for ashwagandha is Withania somnifera, and “somnifera” means “sleep-inducing.” So, that’s a good start.

A 2021 review of five randomized controlled trials concluded that ashwagandha supplements have a “small but significant” beneficial effect on sleep. And the benefits were most pronounced in people with insomnia.

And a 2022 review — which included some of the same studies — reached similar conclusions. The authors write that ashwagandha was associated with falling asleep faster, having better sleep, sleeping for longer, and feeling in a better mood when waking.

Again, it looks hopeful. But as the authors of the 2022 review explain, because of the “limited availability of data,” we need more research.

Are there any dangers?

Ashwagandha seems generally safe, and any side effects tend to be relatively mild. The most common are sleepiness, stomach pain, and diarrhea.

Less commonly, people experience giddiness, vertigo, hallucinations, a stuffy nose, a cough, reduced appetite, nausea, constipation, dry mouth, hyperactivity, cramps at night, blurred vision, acid reflux, skin rash, and weight gain.

There have also been some reports that ashwagandha might cause liver damage.

Experts suggest that people with diabetes, hormone-sensitive prostate cancer, or high blood pressure should use ashwagandha “cautiously.” And anyone who is pregnant or breastfeeding should avoid it.

Also, they warn that ashwagandha may interact with other herbs or drugs.

Plus, there’s very little information about the effects of taking ashwagandha in the long term. 

And it's worth noting that supplements aren’t as tightly regulated as medications. This means you can never be sure how much of the active ingredient you’ll get. It could be barely detectable, a megadose, or anywhere in between.

Finally, it's important to keep in mind that supplements might contain other compounds that aren’t on the label.

The take-home message

Stress, anxiety, and insomnia are common concerns. It would be great if a relatively safe and accessible supplement could help.

There are encouraging signs that ashwagandha might reduce feelings of stress and anxiety in healthy adults. And it seems like it might improve sleep.

However — one last time for those in the back — we need more research before we can be sure. 

Levels of interest in ashwagandha are high right now, so the evidence may eventually stack up in its favor.


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