Ashwagandha and sleep
The Latin name of ashwagandha is Withania somnifera, where somnifera means “the one that brings on sleep.” Today, sleep is one of the main reasons people buy this supplement. The editorial team examined which mechanisms may explain ashwagandha’s effect on sleep, what clinical studies and a meta-analysis show, and for whom the expectations of it are realistic.
Sleep and an athlete’s recovery
Sleep is one of the most powerful but most underestimated factors of recovery. During deep sleep, a significant part of the daily growth hormone is released, the nervous system recovers, and motor learning is consolidated. Chronic lack of sleep worsens strength and speed measures, movement accuracy and mood.
Studies with sleep restriction during dieting have shown that lack of sleep shifts the ratio of lost mass in favor of muscle rather than fat. That is, even with the same deficit, a person who sleeps poorly preserves muscle worse.
Athletes and active people have their own “enemies of sleep”: evening workouts with increased excitability, caffeine and pre-workout complexes, competition stress, flights. Hence the demand for means that help fall asleep but do not cause addiction, like sleeping pills.
Ashwagandha is considered such a means. Its advantage is the absence of data on the development of dependence, its disadvantage is the moderateness of the effect. To understand what to expect from it, it is worth looking at the mechanisms and the numbers from studies.
How ashwagandha may affect sleep
The exact mechanism of ashwagandha’s sleep-inducing effect has not been established. In preclinical works, several pathways that may act simultaneously are discussed.
- GABAergic action.Individual components of the extract in experiments interact with GABA receptors — the main inhibitory system of the brain.
- Reduction of stress and cortisol.Excessive activity of the stress axis interferes with falling asleep; in stressed people ashwagandha moderately lowers cortisol.
- Triethylene glycol.Kaushik and colleagues (2017) showed in mice that triethylene glycol from ashwagandha leaves induces non-REM sleep.
- Reduction of anxiety.Anxious thoughts are a frequent cause of insomnia, and an anxiolytic effect has been confirmed in several RCTs.
Interestingly, triethylene glycol is found precisely in the leaves, whereas most clinical sleep studies were conducted with root extracts. So in humans the effect is probably provided by other components or their combination.
Important: ashwagandha is not a “switch,” like sleeping pills. It most likely reduces the overall level of arousal and anxiety, which makes falling asleep easier gradually, with regular intake.
That is why the effect in studies was usually assessed after 6–10 weeks, not after the first capsule.
What clinical studies show
Langade and colleagues (2019) studied adults with insomnia and healthy people. Taking a root extract for 10 weeks improved the time to fall asleep, sleep efficiency and overall sleep quality, measured, in particular, using actigraphy. The effect was more noticeable in the group with insomnia.
Deshpande and colleagues (2020) studied healthy adults with complaints about sleep quality. Ashwagandha extract for 6 weeks improved the self-assessment of sleep quality compared with placebo. Kelgane and colleagues (2020) reported an improvement in sleep in people aged 65–80.
A systematic review and meta-analysis by Cheah and colleagues (2021) combined five RCTs. The conclusion: ashwagandha has a small but statistically significant positive effect on overall sleep measures. The effect was greater in people with insomnia, at a dose of 600 mg per day and above, and a duration of intake from 8 weeks.
Limitations of the evidence base: a small number of studies, short durations, mostly Indian participants, funding of some works by extract manufacturers. For comparison, cognitive behavioral therapy for insomnia has a much stronger evidence base and remains the first-line method for chronic insomnia.
| Study | Participants | Duration | Main result |
|---|---|---|---|
| Langade et al., 2019 | People with insomnia and healthy people | 10 weeks | Improvement in falling asleep and sleep quality |
| Deshpande et al., 2020 | Healthy adults | 6 weeks | Better self-assessment of sleep quality |
| Kelgane et al., 2020 | 65–80 years | 12 weeks | Improvement in sleep and well-being |
| Cheah et al., 2021 | Meta-analysis of 5 RCTs | — | Small significant effect |
How to take it for sleep
In sleep studies, 300 mg of standardized root extract twice a day or 600 mg per day were most often used. The meta-analysis showed that a dose of 600 mg and above is associated with a better result. The extracts in the studies were standardized by withanolide content.
Timing: for sleep it is logical to take the entire dose or most of it in the evening, an hour or two before bed. Some people feel slight drowsiness during the day as well, so at the start it is better to check the reaction on weekends.
The result should be assessed no earlier than after 6–8 weeks of regular intake. If sleep has not changed during this time, there is no point in continuing — it is worth looking for other causes of the disturbances.
Ashwagandha works better against a background of sleep hygiene: a regular bedtime, a cool dark bedroom, limiting caffeine after lunch and screens before bed. If you drink a pre-workout complex at 7 p.m., no herb will compensate for that.
Limitations and interactions
Ashwagandha should not be combined with sleeping pills, benzodiazepines, barbiturates, alcohol and other sedatives without a doctor’s permission: an enhancement of the depressant effect on the nervous system is possible.
If insomnia lasts more than three months, is accompanied by snoring with breathing pauses, daytime sleepiness, depressed mood or anxiety, an examination is needed. Conditions such as obstructive sleep apnea are not treated with supplements and can have serious consequences.
The general precautions regarding ashwagandha remain: pregnancy and breastfeeding, diseases of the thyroid gland and liver, autoimmune diseases, taking immunosuppressants. Rare cases of liver damage have been described precisely with regular intake.
Finally, the drowsiness that helps in the evening may interfere in the morning. If after taking ashwagandha it is hard to wake up or a “sluggishness” appears at workouts, the dose or timing should be reconsidered together with a specialist.
Editorial conclusions
Ashwagandha has real but small data on improving sleep. Those who may benefit most are people with mild insomnia and stress who take a standardized root extract for at least 8 weeks.
It is not a sleeping pill and does not replace either sleep hygiene or the treatment of serious disorders. For athletes, its value lies in gentle support of recovery without the risk of dependence characteristic of sleeping pills.
We also recommend our articles “Ashwagandha after 40,” “Ashwagandha or rhodiola: what is the difference” and “Side effects of ashwagandha.”
References
- Cheah KL, Norhayati MN, Husniati Yaacob L, Abdul Rahman R. Effect of ashwagandha (Withania somnifera) extract on sleep: a systematic review and meta-analysis. PLoS One. 2021;16(9):e0257843.
- Langade D, Kanchi S, Salve J, et al. Efficacy and safety of ashwagandha (Withania somnifera) root extract in insomnia and anxiety: a double-blind, randomized, placebo-controlled study. Cureus. 2019;11(9):e5797.
- Deshpande A, Irani N, Balkrishnan R, Benny IR. A randomized, double blind, placebo controlled study to evaluate the effects of ashwagandha (Withania somnifera) extract on sleep quality in healthy adults. Sleep Med. 2020;72:28–36.
- Kelgane SB, Salve J, Sampara P, Debnath K. Efficacy and tolerability of ashwagandha root extract in the elderly for improvement of general well-being and sleep: a prospective, randomized, double-blind, placebo-controlled study. Cureus. 2020;12(2):e7083.
- Kaushik MK, Kaul SC, Wadhwa R, et al. Triethylene glycol, an active component of ashwagandha (Withania somnifera) leaves, is responsible for sleep induction. PLoS One. 2017;12(2):e0172508.
- Nedeltcheva AV, Kilkus JM, Imperial J, et al. Insufficient sleep undermines dietary efforts to reduce adiposity. Ann Intern Med. 2010;153(7):435–441.
- Qaseem A, Kansagara D, Forciea MA, et al. Management of chronic insomnia disorder in adults: a clinical practice guideline from the American College of Physicians. Ann Intern Med. 2016;165(2):125–133.
Andriy Melnyk
A strength-sports coach and author of programs for beginner and intermediate levels. Writes about training planning.
