Condition
    Moderate Evidence
    Effectiveness 4/5

    Ashwagandha for Insomnia

    Trials of standardised ashwagandha extract in insomnia report improved sleep onset latency and sleep quality over 6-8 weeks, with larger effects in people whose insomnia sits alongside high stress.

    Overview

    Ashwagandha improves sleep, but modestly and mostly through the door of stress. The 2021 PLOS ONE systematic review and meta-analysis pooled randomised trials and found a small but statistically significant improvement in sleep quality, with larger effects in participants who had a clinical insomnia diagnosis, at doses of at least 600 mg daily and over treatments lasting eight weeks or more. What this looks like in practice is not sedation. Trials report better sleep onset latency, sleep efficiency and subjective sleep quality alongside reduced anxiety, which is consistent with lowering hyperarousal rather than inducing sleep. It suits the person lying awake with a busy, stressed mind more than the person with a circadian problem or sleep apnoea, and it does not replace cognitive behavioural therapy for insomnia, which remains first-line.

    Verdict

    Likely effective

    A meta-analysis of randomised trials shows ashwagandha produces a small but significant improvement in sleep quality, with larger effects in diagnosed insomnia at doses of 600 mg or more for eight weeks or longer.

    How It Works

    The best-supported route is GABAergic. Withanolides and the glycowithanolide fraction show GABA-mimetic activity at GABA-A receptors in preclinical models, and triethylene glycol, isolated from ashwagandha leaves, has been shown to induce non-rapid-eye-movement sleep in animals. This dampens cortical arousal rather than forcing sedation, which fits the clinical picture of easier sleep onset without next-day grogginess in most trial participants. The second route is the stress axis. Randomised trials consistently report lower serum cortisol and reduced perceived stress alongside the sleep changes, and chronic HPA activation is a well-established driver of insomnia through delayed sleep onset and fragmented sleep. Serotonergic effects have also been proposed from animal work. Since sleep improvement tracks anxiety improvement across trials, the plausible reading is that ashwagandha treats the arousal that causes the insomnia rather than the sleep itself.

    Pathways involved

    GABA-A receptor modulation
    Non-REM sleep induction (triethylene glycol)
    HPA axis and cortisol reduction
    Cortical hyperarousal
    Serotonergic signalling (preclinical)

    Dosing & Protocol

    The meta-analysis found benefit concentrated at doses of 600 mg per day or more, sustained for at least eight weeks. Trials most often used 300 mg twice daily of a root extract standardised to withanolides, typically 5%, with the KSM-66 and Shoden preparations the most commonly studied; the Cureus insomnia and anxiety trial used 300 mg twice daily and the 2020 Sleep Medicine trial in healthy adults used 300 mg twice daily of a high-concentration extract. Dose timing is more flexible than for a sedative. Splitting morning and evening matches the trial protocols and reflects the stress-axis mechanism, though some people prefer the full dose an hour or two before bed. Take with food to reduce the gastrointestinal upset that is the commonest complaint. Root extract is what was tested — leaf-containing extracts have a different withanolide profile and have been implicated in liver injury reports.
    ScenarioDoseFormTiming
    Trial standard300 mg twice daily (600 mg/day)Root extract, 5% withanolidesWith food, morning and evening
    Meta-analysis threshold600 mg/day or moreStandardised root extractEffects concentrated above this dose
    Evening-weighted option600 mg once dailyStandardised root extract1-2 hours before bed
    Higher-concentration extracts120-240 mg/dayShoden or equivalent high-withanolide extractFollow the product standardisation
    Minimum duration8 weeks-Shorter trials showed weaker effects
    AvoidLeaf-containing extracts-Different withanolide profile; liver injury reports
    1. 1

      Rule out the insomnia that needs other treatment· Before starting

      Sleep apnoea, restless legs, untreated depression and shift-work circadian disruption do not respond to adaptogens and have specific treatments.

    2. 2

      Put the basics in place· Ongoing

      Cognitive behavioural therapy for insomnia is first-line and outperforms any supplement. Consistent wake time and caffeine timing matter more than the dose you choose.

    3. 3

      Choose a standardised root extract· At purchase

      600 mg/day of root extract standardised to withanolides. Avoid leaf-containing products.

    4. 4

      Take 300 mg twice daily with food· Weeks 1-8

      Morning and evening, matching the trial protocol, or the full dose in the evening if you prefer.

    5. 5

      Review at 8 weeks· Week 8

      Judge on sleep onset time, night waking and how rested you feel, ideally with a simple sleep diary. Benefit in trials required at least eight weeks.

    Evidence

    The 2021 PLOS ONE systematic review and meta-analysis is the reference point. Pooling randomised placebo-controlled trials, it found a small but significant improvement in overall sleep quality, with subgroup analysis showing meaningfully larger effects in participants with diagnosed insomnia, at doses of 600 mg per day or more, and with treatment durations of eight weeks or longer. Anxiety and mental alertness on waking also improved. The individual trials fill in the detail. The 2019 Cureus randomised controlled trial in insomnia and anxiety reported improvements in sleep onset latency, total sleep time, sleep efficiency and anxiety scores, with good tolerability. The 2020 Sleep Medicine randomised double-blind placebo-controlled study extended the finding to healthy adults without insomnia, showing improved sleep quality on actigraphy and questionnaire measures. The consistent limitation across all of them is small samples and a heavy concentration of trials from a single region and a small number of extract manufacturers.
    Best available evidence
    One meta-analysis of randomised trials plus two randomised placebo-controlled trials
    Typical effect
    Small overall improvement in sleep quality; larger in diagnosed insomnia
    Studied dose
    600 mg/day standardised root extract
    Time to effect
    8 weeks or more
    Key limitation
    Small samples, geographic concentration, manufacturer-linked trials
    Certainty of evidence
    Moderate for sleep quality; not a substitute for CBT-I

    A systematic review and meta-analysis of ashwagandha extract on sleep, a randomised controlled trial in insomnia and anxiety, and a randomised double-blind placebo-controlled study of sleep quality in healthy adults.

    Effect of Ashwagandha (Withania somnifera) extract on sleep: A systematic review and meta-analysis

    Score: 9/10
    2021
    meta_analysis
    n=400

    Kae Ling Cheah, Mohd Noor Norhayati, Lili Husniati Yaacob +1 more

    Ashwagandha extract produced a small but significant improvement in overall sleep compared with placebo, with larger effects at doses of at least 600 mg/day for 8 weeks or more.

    View source

    A randomized, double blind, placebo controlled study to evaluate the effects of ashwagandha (Withania somnifera) extract on sleep quality in healthy adults

    Score: 6/10
    2020n=150

    Deshpande A, Irani N, Balkrishnan R +1 more

    Ashwagandha root extract improved sleep onset latency, total sleep time and sleep efficiency in both healthy volunteers and insomnia patients.

    View source

    Efficacy and Safety of Ashwagandha Root Extract in Insomnia and Anxiety

    Score: 6/10
    2019n=60

    Langade D, Kanchi S, Salve J +2 more

    Ashwagandha root extract improved sleep quality and reduced anxiety scores in patients with insomnia, with good tolerability.

    View source

    Safety

    In trials ashwagandha was well tolerated over eight to twelve weeks, with adverse events close to placebo. The common complaints are mild: gastrointestinal upset, nausea, loose stools and daytime drowsiness, most of which improve when taken with food. Three cautions carry more weight. Case reports of liver injury have accumulated, including cholestatic hepatitis, often associated with leaf-containing or poorly characterised products — stop immediately and seek medical advice if jaundice, dark urine, pale stools or right upper quadrant pain appear. Ashwagandha can raise thyroid hormone levels, which risks precipitating thyrotoxicosis in people with hyperthyroidism or on levothyroxine. And because it stimulates several immune functions, caution applies in autoimmune disease and with immunosuppressive therapy. Avoid in pregnancy, where traditional abortifacient use and animal data make it inadvisable, and while breastfeeding. Long-term safety beyond about twelve weeks has not been established.

    Stop immediately for signs of liver injury

    Jaundice, dark urine, pale stools, persistent nausea or right upper quadrant pain warrant stopping ashwagandha and seeking medical assessment. Liver injury case reports are uncommon but well documented, particularly with leaf-containing products.

    Interactions & Conflicts

    Interacts withSeverityMechanismAction
    Levothyroxine and thyroid conditions
    high
    		Ashwagandha can raise T3 and T4, risking thyrotoxicosisAvoid in hyperthyroidism; monitor thyroid function if on levothyroxine
    Sedatives, benzodiazepines and alcohol
    moderate
    		Additive GABAergic and sedative effectsAvoid combining or reduce dose under advice
    Immunosuppressants and autoimmune disease
    moderate
    		Immune-stimulating effects may oppose therapy or provoke flaresAvoid without specialist advice
    Existing liver disease or hepatotoxic drugs
    high
    		Case reports of drug-induced liver injuryAvoid; monitor liver function if used
    Antihypertensives and antidiabetic drugs
    moderate
    		May modestly lower blood pressure and glucoseMonitor readings when starting
    Pregnancy and breastfeeding
    high
    		Traditional abortifacient use and absent safety dataAvoid
    Surgery
    moderate
    		Additive effects with anaesthesia and sedativesStop at least 2 weeks before

    References

    1. Cheah KL et al. Effect of Ashwagandha (Withania somnifera) extract on sleep: a systematic review and meta-analysis. PLOS ONE. 2021
    2. Langade D et al. Efficacy and safety of ashwagandha root extract in insomnia and anxiety: a double-blind, randomized, placebo-controlled study. Cureus. 2019
    3. Deshpande A et al. A randomized, double blind, placebo controlled study to evaluate the effects of ashwagandha extract on sleep quality in healthy adults. Sleep Med. 2020

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