Herb Profile
Withania somnifera
Ashwagandha (Withania somnifera) is a root extract studied mainly for persistent stress, stress related anxiety, and sleep rather than immediate relief.
Use extra caution — GI upset, rare thyroid stimulation Details
Best for
Not ideal for
Safety: Discuss with a clinician first if you have thyroid disease, are pregnant, or take sedatives; rare liver-injury reports exist.
On the evidence: Multiple randomized trials for stress and cortisol, though many are small and industry-funded.
Consider instead: L-theanine — for acute, in-the-moment calm
Why not higher
Why not lower
Practical takeaway: Reasonable to try for chronic stress over 6–8 weeks. It is a support, not a treatment for a diagnosed anxiety or mood disorder — involve a clinician for those.
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Evidence Engine proof of concept
A claim-level view for one practical question: does the evidence justify considering ashwagandha for perceived stress?
Bottom line
Decision snapshot
The evidence supports a cautious trial only for people whose safety context fits. It does not support treating ashwagandha as risk-free or as a replacement for care.
Claim evidence breakdown
This grade applies only to the perceived-stress claim below; the profile-wide evidence grade above summarizes the ingredient across its broader evidence record.
Supporting evidence
| Year | Type | Population | Sample | Duration | Result | Relevance |
|---|---|---|---|---|---|---|
| 2012 | Randomized, double-blind, placebo-controlled trial | Adults with chronic self-reported stress | 64 | 60 days | High-concentration root extract improved perceived stress and related well-being measures versus placebo. | Directly supports the claim, but it is small and extract-specific. |
| 2019 | Randomized, double-blind, placebo-controlled three-arm trial | Stressed healthy adults with elevated perceived stress scores | 60 | 8 weeks | Ashwagandha groups reported greater stress reduction than placebo; pharmacologic stress markers also moved favorably. | Directly relevant to generally healthy adults, with dose comparison, but still small. |
| 2021 | Randomized, double-blind, placebo-controlled trial | Healthy stressed adults | 130 | 90 days | Sustained-release root extract improved validated stress and sleep measures and lowered cortisol versus placebo. | A larger short-term trial that supports the stress claim, though it uses one standardized extract. |
| 2022 | Randomized, placebo-controlled trial | Adults reporting perceived stress | 60 | 30 days | Root-and-leaf extract groups reported improvements in stress, anxiety, mood, and cravings; one dose lowered salivary cortisol. | Useful supportive signal, but the 30-day window and root/leaf extract limit generalization. |
Contradictory evidence
Safety before sourcing
What we still do not know
Source trail
Next decisions
Informational to commercial: understand what ashwagandha can and cannot support, then choose a standardized product with safety context.
| Use case | Evidence | Best fit | Typical range | Safety context |
|---|---|---|---|---|
| Stress and perceived tension | Moderate | Adults with chronic perceived stress | 300-600 mg/day standardized root extract | Review thyroid, pregnancy, autoimmune, liver, and sedative context. |
| Sleep quality | Moderate | Stress-linked sleep disruption | 300-600 mg/day, often evening or split dose | Can add to sedating products. |
| Anxiety symptoms | Preliminary to moderate | Stress-anxiety overlap, not acute panic | Trial windows usually 6-8 weeks | Not a replacement for anxiety care. |
| Testosterone/fertility markers | Preliminary | Stress-related male fertility or training contexts | Study-specific extracts; avoid broad hormone claims | Endocrine history changes the risk/benefit picture. |
Safety
GI upset, rare thyroid stimulation
High caution
Caution level: High. Multiple caution categories apply, or the record uses avoid/contraindication language.
Evidence-based safety
Severity and certainty are shown separately. A high-priority caution can still be theoretical: these pairings are screened from shared contraindication mechanisms and are not automatically documented clinical interactions. Provenance identifies the source fields that produced each flag; it does not upgrade the certainty of the pairwise claim.
Sedation / CNS depression
Representative pairings are shown below. Large mechanism groups are intentionally summarized to keep profiles focused and crawl-efficient.
Data provenance recorded for 68 of 68 pairings in this mechanism group.
+56 more pairings share this mechanism. Use the Safety Checker to review a specific combination.
Evidence
Most useful for practical interpretation when safety context also fits.
Human clinical evidence: Present in source signals
Mechanistic / preclinical: Mechanism mapped — Inflammatory Signaling Modulation · Neurotransmitter Modulation · Hormonal Signaling Context
Research maturity: Established research — Long Term Human Evidence May Be Limited.
Safety boundary: Safety note available — GI upset, rare thyroid stimulation
This profile cites 13 human studies.
Evaluation of methodological rigor, population reach, and evidence alignment.
Each grade reflects the strength and consistency of published human evidence — not marketing claims. Grades are based on study count, design quality, effect size, consistency, and recency.
Filter by study class
Showing 16 of 16 studies.
What the evidence actually shows
This table contains 16 structured sources, including 11 human evidence sources; 4 are human trials. Across 2 human evidence sources with a reported sample size, the approximate participant total is 958; overlapping publications may include some of the same people. Source-to-conclusion relationships are not classified in this structured set, so consistency is not yet classifiable.
Profile-wide evidence grade: see the profile grade above · Confidence: not separately assigned
What would change our conclusion?
Larger, well-controlled human trials using comparable populations, doses, preparations, and clinically meaningful outcomes could materially strengthen or weaken this conclusion. Replication in a different population or a high-quality synthesis resolving current disagreement could also materially change confidence.
| Study | Design | N | Dose | Duration | Population | Outcome | Result & magnitude | Source |
|---|---|---|---|---|---|---|---|---|
Effect of Ashwagandha (Withania somnifera) extract on sleep: A systematic review and meta-analysis Cheah KL et al. · PLoS One · 2021 Background | Meta-analysis Statistically combines results from multiple eligible studies; confidence still depends on the quality, consistency, and directness of those studies. | n=400 | — | — | — | — | — | PubMed → |
Arumugam V et al. · Explore (NY) · 2024 Background | Meta-analysis Statistically combines results from multiple eligible studies; confidence still depends on the quality, consistency, and directness of those studies. | n=558 | — | — | — | — | — | PubMed → |
2024 Background | Meta-analysis Statistically combines results from multiple eligible studies; confidence still depends on the quality, consistency, and directness of those studies. | — | — | — | — | — | — | DOI → |
2022 Background | Meta-analysis Statistically combines results from multiple eligible studies; confidence still depends on the quality, consistency, and directness of those studies. | — | — | — | — | — | — | DOI → |
Background | Meta-analysis Statistically combines results from multiple eligible studies; confidence still depends on the quality, consistency, and directness of those studies. | — | — | — | — | — | Lower cortisol, modest T4 increase, and higher testosterone in men; TSH/T3 and female testosterone effects were not significant. | PubMed → |
Background | Meta-analysis Statistically combines results from multiple eligible studies; confidence still depends on the quality, consistency, and directness of those studies. | — | — | — | — | — | Pooled evidence reported improvements in memory, attention/processing, and executive-function measures. | PubMed → |
Background | Meta-analysis Statistically combines results from multiple eligible studies; confidence still depends on the quality, consistency, and directness of those studies. | — | — | — | — | — | Pooled randomized evidence favored ashwagandha for stress, depression, and anxiety outcomes. | Ashwagandha significantly improved stress (SMD -5.88, 95% CI -8.15 to -3.60), depression (SMD -5.68, 95% CI -8.43 to -2.94), and anxiety (SMD -6.87, 95% CI -8.77 to -4.97). | PubMed → |
Lopresti AL et al. · Medicine (Baltimore) · 2019 Background | Randomized controlled trial Randomly assigns participants to interventions or controls, reducing many sources of bias when the trial is conducted well. | — | — | — | — | — | — | PubMed → |
Background | Randomized controlled trial Randomly assigns participants to interventions or controls, reducing many sources of bias when the trial is conducted well. | — | — | — | — | — | Large multicenter randomized evidence adds short-term tolerability data for ashwagandha root extract. | PubMed → |
Background | Randomized controlled trial Randomly assigns participants to interventions or controls, reducing many sources of bias when the trial is conducted well. | — | — | — | — | — | 600 mg/day for 8 weeks improved selected cognition, energy, and mood measures versus placebo. | PubMed → |
Background | Randomized controlled trial Randomly assigns participants to interventions or controls, reducing many sources of bias when the trial is conducted well. | — | — | — | — | — | Adds controlled tolerability data in healthy men. | PubMed → |
Ashwagandha as a Unique Cause of Thyrotoxicosis Presenting With Supraventricular Tachycardia 2022 Background | Other / unclear The study design is not yet classified clearly enough to infer its place in the evidence hierarchy. | — | — | — | — | — | — | DOI → |
Ashwagandha-induced liver injury—A case series from India and literature review 2023 Background | Other / unclear The study design is not yet classified clearly enough to infer its place in the evidence hierarchy. | — | — | — | — | — | — | DOI → |
Is it safe to consume traditional medicinal plants during pregnancy? 2020 Background | Other / unclear The study design is not yet classified clearly enough to infer its place in the evidence hierarchy. | — | — | — | — | — | — | DOI → |
Adrenal hypofunction associated with ashwagandha (Withania somnifera) supplementation: a case report 2022 Background | Other / unclear The study design is not yet classified clearly enough to infer its place in the evidence hierarchy. | — | — | — | — | — | — | DOI → |
2023 Background | Other / unclear The study design is not yet classified clearly enough to infer its place in the evidence hierarchy. | — | — | — | — | — | — | DOI → |
Simplified mechanism pathway based on preclinical and pharmacological evidence. Does not confirm clinical efficacy.
Mechanism Pathway — How Ashwagandha Withania Somnifera Works
Preclinical pathways. Proposed mechanisms from in vitro and animal research; these do not confirm clinical outcomes in humans.
Key constituents studied in Ashwagandha Withania Somnifera, with full pharmacology and safety profiles.
Explore botanicals with similar chemistry, effects, or safety considerations in the Botanical Activity Atlas.
Goal guides
Condition guides
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Sourcing options
Product recommendations are not shown for this profile because the current site safety and monetization policy does not permit them.
When sourcing Ashwagandha Withania Somnifera, verify the label for:
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Safety first · Harm reduction
This information is educational and not medical advice. Start low, avoid risky combinations, and consult a licensed clinician before making health decisions—especially if you use medications, have diagnosed conditions, or are pregnant/breastfeeding.
Learn how we evaluate confidence, safety, and intensity on the methodology page.
Checked against primary sources, cited evidence, and contraindication language before publication. Evidence claims, safety language, and affiliate modules are reviewed independently. Not personal medical advice.
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Botanical profile context
Ashwagandha herb profile with evidence context, key research topics, source notes, safety context, and references presented in an evidence-first format. Use this herb profile as a starting point for evidence review, not as a recommendation to start a new supplement. Botanical products can vary by plant part, extract ratio, standardization, dose, and contaminant testing, so two labels with the same common name may not behave the same way.
When reviewing Ashwagandha Withania Somnifera, compare the traditional-use context against the human evidence, mechanism notes, and safety cautions. Pay special attention to pregnancy, breastfeeding, liver or kidney disease, blood-pressure effects, sedation, stimulation, anticoagulant use, antidepressants, and any prescription medication overlap.
For product decisions, prefer transparent labels, named extracts, clear serving sizes, and third-party quality testing. Avoid treating a long list of possible mechanisms as proof that an herb will solve a specific condition.