Ashwagandha for Sleep: Evidence, Safety and Who Should Avoid It
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Ashwagandha for sleep is one of the most searched supplement questions right now, helped along by social media. Ashwagandha (Withania somnifera) is a herb with a long history in traditional medicine, and some trials suggest it may help people fall asleep and sleep a little better. This guide covers what ashwagandha is, what the research found, the caveats, the safety concerns including liver injury, who should avoid it, and what to try instead.
The short answer: a 2021 meta-analysis of five randomised trials found ashwagandha extract had a small but significant effect on overall sleep, with bigger effects in people with insomnia, at doses of 600 mg a day or more, and over eight weeks or longer. The evidence is low to moderate quality, the trials were small, and long-term safety is unknown. Rare cases of liver injury have been linked to ashwagandha supplements, and it isn't recommended in pregnancy or for people with thyroid or autoimmune conditions. Talk to your GP or pharmacist before trying it.
What is ashwagandha?
Ashwagandha is a plant whose root, and sometimes leaf, is used in traditional medicine and is promoted for stress and sleep. You'll find it in capsules, powders, gummies and blends with other ingredients. Products vary a lot in which part of the plant they use, how they're extracted and how much active compound they contain, which makes it hard to compare one study or product with another.
What the research says
The 2021 meta-analysis. A review in PLoS One pooled five randomised controlled trials with 400 participants. Ashwagandha extract had a small but significant effect on overall sleep. The effect was stronger in people with insomnia, at doses of 600 mg a day or more, and when taken for eight weeks or longer. It also improved sleep onset latency, total sleep time, wake after sleep onset and sleep efficiency, as well as mental alertness on waking and anxiety. No serious side effects were reported. The authors rated the evidence low to moderate quality and noted small samples, limited long-term safety data and little research in older adults (source).
A typical trial. One of the better-known studies randomised 60 adults with insomnia to 300 mg of a branded root extract or a starch placebo, twice a day for 10 weeks. Sleep efficiency rose from about 76% to 83% with ashwagandha and from 75% to 80% with placebo. Time to fall asleep at 10 weeks was about 29 minutes with ashwagandha versus 34 minutes with placebo. No adverse events were reported. The extract was supplied by its manufacturer (source).
Notice that placebo also improved things. The real difference attributable to ashwagandha is smaller than the before-and-after numbers suggest.
Evidence at a glance
| Question | What we know |
|---|---|
| Does it help sleep? | Small effect on average in trials |
| Who benefits most? | People with insomnia in the trials |
| What dose was used? | Effects stronger at 600 mg a day or more |
| How long to work? | Effects stronger after eight weeks or more |
| Long-term safety? | Unknown beyond about three months |
| Quality of evidence? | Low to moderate, mostly small trials |
Safety and side effects
This is where ashwagandha needs more care than a cup of herbal tea. The US National Center for Complementary and Integrative Health (NCCIH) says (source):
- Liver injury. Although rare, a number of cases have linked liver injury to ashwagandha supplements.
- Short-term only. It may be safe for up to about three months; there isn't enough information on long-term safety.
- Pregnancy and breastfeeding. It should be avoided during pregnancy and not used while breastfeeding.
- Thyroid and autoimmune conditions. It isn't recommended for people with these conditions, and it may interact with thyroid hormone medicines.
- Other medicines. It may interact with medicines for diabetes and blood pressure, immunosuppressants, sedatives and anticonvulsants.
If you feel unwell while taking it, stop and see your GP promptly. If you think a supplement has caused a side effect, you can report it to the Therapeutic Goods Administration (TGA). Better Health Channel advises buying herbal products from a reputable source and telling your doctor about any herbal medicines you take (source).
Who should avoid it or check first
| Situation | What to do |
|---|---|
| Pregnant or breastfeeding | Avoid |
| Thyroid condition or thyroid medicine | Avoid unless your GP says otherwise |
| Autoimmune condition | Avoid unless your GP says otherwise |
| Liver problems | Talk to your GP first |
| Diabetes, blood pressure, sedative or seizure medicines | Check with your pharmacist |
| Healthy adult, short-term trial | Talk to your pharmacist about the product and dose |
What to try first
For most people with poor sleep, the basics and proven therapies come before supplements:
- Keep a fixed wake-up time, seven days a week. See how to fix your sleep schedule.
- Deal with stress directly if worry is what keeps you up. See anxiety and sleep and racing thoughts at night.
- Try CBT for insomnia if poor sleep has dragged on for months. See CBT for insomnia.
- Compare other remedies with their own evidence, such as magnesium and melatonin in Australia.
When to see your GP
See your GP if you've had trouble sleeping three or more nights a week for months, if you feel low or anxious most days, if you snore loudly and wake unrefreshed, or before starting ashwagandha if you take any regular medicine. If you're struggling, Beyond Blue (1300 22 4636) and Lifeline (13 11 14) are there to talk. This guide is general information, not medical advice.
Where the Sovune Nudge fits
We make the Sovune Nudge, a silent vibrating wristband alarm, so we're not neutral. It's not a sleep aid and has nothing to do with supplements. What it does is give you a calm, consistent wake-up, which is one of the habits that matters most for sleep.
- Wakes you with vibration on your wrist, starting as a gentle tap and building through three intensity levels.
- Silent. No speaker and no sound, so you aren't jolted awake.
- Vibrates for a full minute, stepping up gradually instead of starting at full blast. You can switch it off sooner.
- Set on the band itself. No app, no phone, so the phone can stay out of the bedroom.
It comes with a 30-day money-back guarantee.
Quick answers
Does ashwagandha help you sleep? Trials suggest a small benefit on average, mostly in people with insomnia, but the evidence is low to moderate quality.
How long does ashwagandha take to work for sleep? In the 2021 meta-analysis, effects were stronger with eight weeks or more of use.
Is ashwagandha safe? It may be safe short term for many adults, but rare liver injury has been reported and long-term safety is unknown. Check with your GP or pharmacist first.
Can I take ashwagandha with melatonin or sleeping tablets? Ashwagandha may interact with sedatives, so ask your pharmacist before combining it with any sleep medicine.
For every type of silent alarm compared, see our complete guide to vibrating alarms in Australia.