How much ashwagandha should I take for sleep?

Most sleep trials used 300 mg of a standardised root extract taken twice a day, or 600 mg once in the evening. Benefits on sleep quality and how quickly people fell asleep tended to show up around six to eight weeks, not the first night. Start at the lower end and give it a full cycle before judging it.

When should I take ashwagandha for sleep?

Evening dosing makes sense if you take it once a day, since the goal is easier wind-down. Twice-daily regimens split it morning and night. Ashwagandha is not a sedative that knocks you out, so timing matters less than consistency; taking it at the same time each day is what lets the effect build.

How long does ashwagandha take to work for sleep?

Trials generally measured improvements at six to ten weeks. Some people notice calmer evenings sooner, but the sleep-quality and sleep-onset gains in the studies accumulated over weeks as the extract's compounds built up. Treat it as a slow adjustment rather than a fast-acting sleep aid.

Does ashwagandha help sleep by lowering cortisol?

That is the leading explanation. Ashwagandha has repeatedly lowered morning cortisol in trials, and a calmer stress-hormone curve in the evening should make falling asleep easier. The link between its cortisol effect and its sleep effect is plausible and consistent, though not every study measured both at once.

Best ashwagandha supplement for sleep?

Look for a standardised root extract stating its withanolide percentage, third-party tested, in the 300 to 600 mg daily range the trials used. KSM-66 and Sensoril are the two most-studied standardised forms. Our [ashwagandha page](/products/ashwagandha/) covers extract types and dosing.

ashwagandha

Moderate evidence

Ashwagandha Dosage for Sleep

Ashwagandha for sleep: what the RCTs actually used, the 300 to 600 mg range that shows results, when to take it, and how cortisol ties into better rest.

August 9, 2026

Updated August 2026

Reviewed by Enoch C., MSc — Research & Editorial

On this page

The dose the studies used
What the evidence shows
What to look for in an ashwagandha supplement for sleep
Cautions and interactions

Ashwagandha (Withania somnifera) is an adaptogenic root used in Ayurvedic tradition to help the body handle stress, standardised in modern supplements to its active withanolides. For sleep, the doses that actually showed results in trials sit in a narrow band: 300 mg of a standardised extract twice a day, or 600 mg once in the evening, taken consistently for six to eight weeks. It is not a sedative and it will not knock you out on night one. Its benefit for sleep appears to work through a calmer stress-hormone curve, which is why the effect builds slowly.

If you are choosing an extract, our ashwagandha hub covers standardisation and forms. This post focuses on the dose, the timing, and what the sleep studies really found.

The dose the studies used

Almost every clinical trial on ashwagandha and sleep used a standardised root extract, not raw powder, and stayed within a tight dose range. The two most-studied branded forms are KSM-66 and Sensoril, which differ in how they are extracted and in their withanolide concentration.

A 2019 trial by Langade and colleagues gave people with insomnia and anxiety 300 mg of a full-spectrum root extract twice daily for ten weeks. Sleep onset, sleep quality, and anxiety scores all improved against placebo. A follow-up 2021 study by the same group tested 600 mg per day and again found better sleep efficiency and quality, with clearer gains in people who already had insomnia than in healthy sleepers.

The pattern across trials is consistent: 300 to 600 mg of a standardised extract per day, given time to work. Higher is not obviously better, and most studies capped the daily dose around 600 mg.

What the evidence shows

Pooled analysis backs up the individual trials. A 2021 systematic review and meta-analysis by Cheah and colleagues combined five randomised trials and found ashwagandha produced a small-to-moderate improvement in overall sleep quality, with a stronger effect in people diagnosed with insomnia and at doses of 600 mg per day or more taken for eight weeks or longer.

Study	Design	Dose	Key finding
Langade 2019	RCT, 60 adults	300 mg twice daily	Better sleep onset and quality
Langade 2021	RCT, 80 adults	600 mg daily	Improved sleep efficiency
Salve 2019	RCT, 60 adults	240–600 mg daily	Lower morning cortisol
Cheah 2021	Meta-analysis, 5 RCTs	120–600 mg daily	Modest overall sleep gain

The cortisol thread ties it together. A 2019 trial by Salve and colleagues found that a standardised extract lowered morning serum cortisol against placebo. Cortisol should fall in the evening to let sleep begin, and a stress response stuck in a high gear is a common reason people lie awake. A herb that blunts an over-active cortisol curve plausibly makes the wind-down easier, which fits the slow, cumulative sleep benefit the trials describe. This places ashwagandha at a moderate evidence tier for sleep support, stronger than most single herbs but not a replacement for treating a diagnosed sleep disorder.

What to look for in an ashwagandha supplement for sleep

The dose only means something if the product is standardised, so read the label for the details that map to the trials. Look for a root extract (not leaf, not raw powder) that states its withanolide percentage, since that is the active fraction the studies standardised. Match the studied range: a product delivering 300 to 600 mg per day, so you can reproduce a trial dose rather than guess. The two forms with the most sleep and stress data are KSM-66 and Sensoril, so a named standardised extract is a reasonable quality marker. Insist on third-party testing, because ashwagandha is sometimes adulterated or cut with leaf material. Skip proprietary “sleep blends” that bury the ashwagandha dose among other herbs, which makes it impossible to know what you are taking. Our ashwagandha page sets out extract types and dosing, and the sleep guide shows how it compares with magnesium and L-theanine. Buy on standardisation, withanolide content, and testing.

Cautions and interactions

Ashwagandha is well tolerated in trials, but it is not for everyone. It can cause mild drowsiness, stomach upset, or loose stools, especially early on. Because it can lower cortisol and nudge thyroid hormone upward, people with thyroid conditions or those on thyroid medication should check with a clinician first. Rare reports of liver injury exist, so stop and seek advice if you notice yellowing skin, dark urine, or unusual fatigue.

Ashwagandha may add to the effect of sedatives, benzodiazepines, and other sleep medications, so combining them needs medical oversight. It can also interact with immunosuppressants and blood-sugar or blood-pressure drugs. Pregnancy and breastfeeding are firm reasons to avoid it, as high doses have traditionally been linked to pregnancy risk. The National Center for Complementary and Integrative Health notes these safety limits and the need for more long-term data.

If persistent insomnia is your real problem, a supplement is not the first-line answer. Talk to your prescriber, and if low mood or anxiety is keeping you awake, our get help page points to genuine support.

This article is educational and not medical advice. See our disclaimer and get help page.