Ashwagandha has a reputation as a calming, sleep-friendly herb, and unlike many supplements it has several randomized, placebo-controlled trials on sleep specifically. The results are encouraging but modest, and some of the questions people ask most, like the best time of day to take it, haven't been tested directly. This guide covers what the trials found, how much they used, and how to decide when to take it. For the broader overview, see our ashwagandha guide.
Does Ashwagandha Help You Sleep?
A 2021 meta-analysis of five randomized trials (400 adults) found a small but significant improvement in overall sleep compared with placebo, with a pooled standardised effect of about -0.59 Preliminary. The effect was clearer in adults diagnosed with insomnia, at doses of 600mg a day or more, and after 8 weeks or longer. Mental alertness on waking and anxiety also improved. A 2024 meta-analysis of five trials (254 people) agreed on lower sleep-onset time, longer total sleep time, better sleep efficiency and better PSQI sleep-quality scores, though not for time awake after falling asleep, and it noted very high variation between studies.
What Each Trial Found
| Trial | Dose and length | Result |
|---|---|---|
| 150 healthy adults with non-restorative sleep | 120mg standardized extract once a day, 6 weeks | Self-reported sleep quality up 72% vs 29% on placebo; better sleep efficiency, total sleep time and sleep latency on wrist monitors |
| 60 adults with insomnia and anxiety | 300mg twice a day, 10 weeks | Sleep onset about 29 vs 34 minutes on placebo; better sleep efficiency and sleep quality |
| 80 people (40 healthy, 40 with insomnia) | Root extract, 8 weeks | Improved sleep in both groups, more in the insomnia group |
| 60 college students | 700mg a day, 30 days | Better restorative-sleep scores than placebo; the group-by-time test wasn't significant |
| 200 adults aged 18–50 | 300mg twice a day, 8 weeks | Shorter sleep onset than placebo; compared with 3mg melatonin (below) |
All of these were done with standardised root extracts, and several came from India with industry involvement, so the trials are encouraging but not independent confirmation.
Ashwagandha vs. Melatonin
A 2026 four-arm trial of 200 adults compared 300mg of ashwagandha twice a day, 3mg of melatonin, the two together, and placebo, over 8 weeks. All three active groups fell asleep faster than placebo, ashwagandha and melatonin alone gave moderate and comparable benefits, and the combination was the most consistent on sleep onset, total sleep time, time awake after sleep onset and sleep efficiency. Mild adverse events occurred in all groups. One trial can't settle it, but it suggests ashwagandha is a plausible alternative or add-on for people who don't want to rely on melatonin alone.
What's the Best Time of Day to Take Ashwagandha?
No trial has compared morning with evening dosing, so nobody can tell you the best time from the evidence Not studied. What the trials do show is how it was given:
- One trial gave 120mg once a day for 6 weeks.
- The longer insomnia trial gave 300mg twice a day, with milk or water, for 10 weeks.
- Effects built up over 6 to 10 weeks, so the timing of a single dose mattered less than taking it every day.
With that in mind, a reasonable approach (practical reasoning, not a trial result):
- If you want it for sleep: take the main dose with your evening meal or an hour or two before bed, since drowsiness is a reported side effect.
- If it makes you sleepy: keep it in the evening and avoid taking it before driving or demanding work.
- If you use it for daytime stress: splitting it as 300mg in the morning and 300mg in the evening matches the doses most trials used.
- Be consistent. The benefit builds with daily use, so a regular time you'll remember is better than a perfect one you'll miss.
How Much to Take for Sleep
| Approach | Dose from trials |
|---|---|
| Lower dose, healthy adults with poor-quality sleep | 120mg standardized extract once a day |
| Insomnia | 300mg twice a day (600mg a day), 8–10 weeks |
The meta-analysis found the clearest effects at 600mg a day or more and after 8 weeks or longer, and most trials stopped at 700mg a day. Don't take more than the label says. Our best ashwagandha supplement guide explains how to choose a standardised extract.
How Long Until You Notice
Don't expect a first-night effect. The trials measured sleep after 4 to 10 weeks, and the meta-analysis found effects were bigger after 8 weeks or more. If you notice nothing after about two months at a trial dose, it may not be for you.
Side Effects and Who Should Be Careful
- Drowsiness is the one that matters here. In a 2026 review of 23 trials, mild effects like stomach upset, headache and transient drowsiness were infrequent and also occurred on placebo.
- Sedatives and sleep medication: it may add to their effect, so ask a doctor or pharmacist first.
- Alcohol: no study has tested it alongside; see is ashwagandha safe?.
- Thyroid, liver, pregnancy, autoimmune conditions: check with a doctor first. The safety guide has the details, including the rare liver injury and thyroid case reports.
If poor sleep is persistent or comes with loud snoring, daytime sleepiness or low mood, it's worth seeing a doctor rather than relying on a supplement.
For the stress side of the story, see ashwagandha for anxiety and stress. If you're comparing sleep supplements, L-theanine dosage covers another popular option.
