Claim deep dive·Emerging evidence·Updated July 13, 2026
Evidence review: Ashwagandha improves sleep quality
Smaller and less consistent than the stress effect, but a 2021 meta-analysis (Cheah et al.) found significant improvement in sleep quality, especially in adults with insomnia.
The bottom line.
The strongest studies.
Sorted by study tier (meta-analyses first, then RCTs, then reviews) and recency. Every entry links to PubMed by PMID, and every citation on this page points here.
Meta-analyses & systematic reviews
3- 1Biopsychological Effects of Ashwagandha (Withania somnifera) in Athletes and Healthy Individuals: A Systematic ReviewSource linkedPMIDFerreira JF, Ferreira RM, Maia F et al. · Muscles (Basel, Switzerland) · 2025
- 2Efficacy of ashwagandha in improving sleep quality: a systematic review and meta-analysisSource linkedPMIDCheah KL, Norhayati MN, Husniati Yaacob L et al. · PLoS One · 2021
Ashwagandha extract significantly improved overall sleep quality
- 3Effect of Ashwagandha (Withania somnifera) extract on sleep: A systematic review and meta-analysisSource linkedPMIDCheah KL et al. · PLoS One · 2021
Small but significant effect on overall sleep (SMD -0.59) across 5 RCTs; more prominent benefit in adults with diagnosed insomnia
Randomized controlled trials
2- 4A standardized Ashwagandha root extract alleviates stress, anxiety, and improves quality of life in healthy adults by modulating stress hormones: Results from a randomized, double-blind, placebo-controlled study.Source linkedPMIDMajeed M, Nagabhushanam K, Mundkur L · Medicine · 2023
Standardized ashwagandha root extract significantly reduced cortisol levels and perceived stress while improving quality of life scores in healthy adults.
- 5Exploring the efficacy and safety of a novel standardized ashwagandha (Withania somnifera) root extract (Witholytin®) in adults experiencing high stress and fatigue in a randomized, double-blind, placebo-controlled trialSource linkedPMIDSmith SJ, Lopresti AL, Fairchild TJ · Journal of psychopharmacology (Oxford, England) · 2023
What pushes back.
Caveats, null findings, and methodological limits that hold the tier where it is.
What the evidence supports.
What we recommend
600 mg/day standardized extract in the evening for 6 to 8 weeks. Effect is more reliable in those with diagnosed insomnia than in healthy sleepers.
Tier criteria: /methodology/evidence-tiers. Sourcing standards: /methodology/interactions.
Common questions.
Quick answers drawn from the verdict, evidence, and recommendation above.
Does the evidence support the claim that ashwagandha improves sleep quality?
Smaller and less consistent than the stress effect, but a 2021 meta-analysis (Cheah et al.) found significant improvement in sleep quality, especially in adults with insomnia.
How strong is the evidence behind Ashwagandha for this claim?
NutriStack rates this as Emerging evidence, meaning early RCT signal, mechanistic data, or limited human evidence. Full tier criteria are at https://nutristackapp.com/methodology/evidence-tiers.
What contrary evidence or caveats apply?
Many of the same trials are credited for both stress and sleep, making it hard to isolate the sleep effect. Effect on objective sleep measures (PSG, actigraphy) is weaker than on self-reported quality.
What does NutriStack recommend?
600 mg/day standardized extract in the evening for 6 to 8 weeks. Effect is more reliable in those with diagnosed insomnia than in healthy sleepers.
Selected claims, opened up
This is how NutriStack presents an evidence review.
Each published claim review shows its verdict, attached studies, contrary evidence, dose context, and limits. Coverage is selective rather than a claim that every database assertion has received the same review.