Ashwagandha improves sleep quality

Pooled trials found ashwagandha improved sleep compared with placebo, with a small effect. Pooling five randomized placebo-controlled trials covering 400 adults, the effect on overall sleep was statistically significant and small in size, and larger in people diagnosed with insomnia, at 600mg a day or more, and over 8 weeks or longer. Nearly all of this research tested one branded root extract, in India. The Brazilian Sleep Association's 2023 guideline on insomnia in adults does not recommend ashwagandha for insomnia, and it recommends cognitive behavioral therapy for insomnia.

Three things shape who it helps and how much. The first is who you are. One 8-week trial split its participants into those with insomnia and those without: the insomnia group saw improvements in sleep quality, time to fall asleep, and morning alertness, while participants without insomnia reported better sleep but no change in alertness or anxiety. A 6-week trial in 150 people with non-restorative sleep found 72% reported better sleep quality on ashwagandha against 29% on placebo, with wrist actigraphy also showing gains in sleep efficiency, total sleep time and time to fall asleep. The largest trial since, 200 adults with trouble falling asleep followed for 8 weeks and published in 2026, measured sleep with a wrist device: time to fall asleep fell by about 15 minutes on ashwagandha and about 7 minutes on placebo. A 3mg melatonin tablet did about as well as ashwagandha, and the two together did best, in people without serious illness and not on regular medication. A 2024 pooled analysis found gains in time to fall asleep, total sleep time, sleep efficiency and sleep quality scores, but no change in time awake during the night.

The second is dose and duration. Effects were stronger at 600mg per day and at treatment lasting at least 8 weeks. Shorter courses and lower doses showed less. The trials gave ashwagandha daily for 6 to 12 weeks; none tested a single dose.

The third is what was actually tested. Every sleep trial cited here was run in India. Four of the five pooled trials, and the 2026 trial, used the same branded root extract at 250mg to 600mg a day; the fifth used a different branded extract made from root and leaf, at 120mg a day. Several of these trials were run by overlapping teams of investigators, and the 2026 trial's paper reports no outside funding while its trial registration names the extract's maker as sponsor and funder. So the research largely describes one product, and a bottle made a different way is not what was studied.

Ashwagandha has been well tolerated in trials lasting up to about three months, with mild side effects such as stomach upset, loose stools and drowsiness. Beyond three months, safety has been followed in one 12-month study of 191 adults, sponsored by the extract's maker: liver, kidney and thyroid blood tests showed no clinically significant change and the side effects reported were mild, but the study had no comparison group, so it cannot show what the extract itself did. Separately, acute liver injury has been documented in case reports and case series, including five people who took products containing 450 to 1,350mg daily for between one week and four months and developed jaundice, itching, nausea and elevated bilirubin. Their condition improved after stopping. In several of those cases the product contents were never independently verified and some were multi-ingredient. LiverTox, the US government's drug-induced liver injury database, rates ashwagandha a likely cause of liver injury. Reports have increased since the first in 2017, typically appearing 2 to 12 weeks after starting, and in several other cases the product was tested and found to contain ashwagandha with no contaminants. Most cases were mild to moderate and resolved within 1 to 4 months of stopping, but rare cases have ended in death or emergency liver transplant, particularly in people with existing liver disease, and LiverTox states that people with cirrhosis or advanced chronic liver disease should avoid it. Ashwagandha has also been shown to alter thyroid hormone levels, and it may interact with sedatives, thyroid medication, blood pressure and diabetes medication, and immunosuppressants. US prescribing labels for digoxin, a heart medicine, also warn that ashwagandha can interfere with some digoxin blood tests, making the measured level read higher than it is.

Denmark banned ashwagandha in 2023 following a risk assessment. France's food safety agency recommended in 2024 against its use by pregnant and breastfeeding women and people with endocrine disorders.