Does Ashwagandha Actually Lower Stress? The Evidence

Ashwagandha (Withania somnifera) is a small shrub used for centuries in Ayurvedic medicine, the traditional medicine of India. In modern supplements it is sold as a standardised extract of the root, often labelled by how much of its active compounds, called withanolides, it contains.

It gets marketed as an adaptogen, a loose term for a substance said to help the body cope with stress. Adaptogen is not a precise scientific category, so ignore the word and look at what the trials measured: two things mainly, your cortisol and your self-reported stress and anxiety. Those are different questions, and ashwagandha does not perform the same on both.

Cortisol is the hormone your body releases when it is under sustained stress. Chronically high cortisol is linked to poor sleep, belly fat, and feeling wired but tired. It is also easy to measure in blood, which is why so many ashwagandha trials use it as their headline number.

Here the evidence is fairly steady. In the most cited early trial, 60 days of a full-spectrum root extract lowered serum cortisol by about 28 percent compared with placebo. Newer pooled analyses agree on the direction: a 2025 systematic review that combined many trials found ashwagandha significantly reduced cortisol across studies.

The whole point of a stress supplement is to feel less stressed. So researchers also use questionnaires, most often the Perceived Stress Scale, which asks how overwhelmed and out of control you have felt lately.

Several trials do show ashwagandha beating placebo on these scales and on anxiety ratings. But the picture is shakier than the cortisol data. One 2025 meta-analysis found the striking split named in its own title: ashwagandha produced a significant cortisol reduction but no significant effect on perceived stress. In plainer words, the blood number moved but the how-do-you-feel score did not, in that pooled set of studies.

So the honest read is: ashwagandha probably helps some people feel calmer, and it moves cortisol fairly reliably, but the claim that it dependably makes you feel less stressed is not as solid as the marketing implies. Effects also vary a lot person to person.

Trials that found benefits mostly used a standardised root extract, not raw powder, at doses in this range.

It is not a fast acting pill you take before a stressful meeting. If you try it, judge it over about two months, not two days. And more is not better: the trials do not support megadoses, and higher amounts raise the odds of side effects.

The research is genuinely encouraging, but it has real weaknesses that the supplement industry rarely mentions.

• Small and short. Many trials enrol only a few dozen people for eight to ten weeks. Small, short studies overstate effects more often than large ones.
• Concentrated in one region. A large share of the trials were run in India, so we know less about how well the results carry across different diets and populations.
• Industry ties. Some studies were funded or run by companies that sell the extract. That does not make them wrong, but it is a reason for caution, not blind trust.
• Publication bias. Studies that find nothing are less likely to get published, which tilts the pooled picture toward positive results.

In trials, ashwagandha is usually well tolerated. The most common complaints are mild: drowsiness, an upset stomach, or loose stools. But well tolerated is not the same as safe for everyone.

Supplements are lightly regulated, so quality varies. If you buy it, choose a product that is third party tested and states the extract and withanolide content on the label. And tell your doctor you are taking it, the same as any other medicine.