Rankings / Mood, Anxiety & Stress

Ashwagandha (Withania somnifera)

Mood, Anxiety & Stress · Adaptogen

Also known as: KSM-66 ·Sensoril

Tier B-

Reviewed by Read Off Label · Last reviewed · How we grade

gabaadaptogenthyroidotcanti-inflammatory
6.3 / 10
Tier B-
Ev 6 Bn 5 Sf 7

Bottom line

Read Off Label grades Ashwagandha (Withania somnifera) as B- (6.3/10) based on moderate evidence, moderate benefit magnitude, and a low-med-risk safety profile.

Ashwagandha is widely marketed in Western supplement channels, and multiple clinical trials include Chandrasekhar 2012 and Lopresti 2019 and 2021.

Studied, labeled, or reported-use context: 300-600 mg/day standardized extract (KSM-66 or Sensoril most studied) — OTC; not individualized guidance.

If you were testing this on yourself

Two properties decide whether an n-of-1 experiment is readable and recoverable. These describe the experiment — they are not a judgment about whether to run it, and nothing here is a recommendation.

Can you undo it?

Slow to reverse

Effects fade within weeks of stopping, but liver injury has been reported in case series and does not resolve immediately; thyroid hormone changes also take time to normalise. Not a same-day off switch.

Can you tell if it worked?

Readable — 4–8 weeks

Subjective stress and sleep. Cortisol testing is available but noisy and hard to interpret. Thyroid panel is worth a baseline if you are on thyroid medication.

What would fool you Stress is strongly self-limiting and regresses to the mean — people start supplements at a bad patch, which is exactly when things improve anyway. Expectancy effects on subjective stress are among the largest measured for any supplement.

What the evidence says

Ashwagandha is widely marketed in Western supplement channels, and multiple clinical trials include Chandrasekhar 2012 and Lopresti 2019 and 2021. Iceland and Denmark added warnings 2023 after multiple case reports of DILI (drug-induced liver injury). Time separation from thyroid hormone is used because coadministration can affect absorption. Cycling appears in chronic consumer-use protocols but has not been validated in comparative trials. Emerging 2025-2026 case reports describe HPA-axis suppression and withdrawal-type symptoms with chronic use; they are too sparse to establish incidence or whether cycling changes risk. A 2026 meta-analysis (20 RCTs, n=1,249) reported significant cognitive gains - memory SMD 0.52, attention/processing speed SMD 0.29 - plus muscle-strength, testosterone, and body-composition improvements (GRADE-assessed; Front Pharmacol 2026).

Mechanism

Ayurvedic 'Indian ginseng'; withanolides (withaferin A, withanolide D); HPA axis modulation — reduces cortisol response to stress; GABAergic; thyroid-stimulating effects

Studied, labeled, or reported dose & route

300-600 mg/day standardized extract (KSM-66 or Sensoril most studied)

This records doses and routes described in studies, approved labeling, clinical practice, or documented use. It is not individualized guidance and does not establish safety; context changes with indication, formulation, health history, monitoring, and other medicines.

Citations

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Common questions

What does the evidence show about Ashwagandha (Withania somnifera)'s effects?
Read Off Label rates the evidence for Ashwagandha (Withania somnifera) as Moderate and the benefit magnitude as moderate, producing an overall grade of B- (6.3/10). Ashwagandha is widely marketed in Western supplement channels, and multiple clinical trials include Chandrasekhar 2012 and Lopresti 2019 and 2021.
What safety findings are reported for Ashwagandha (Withania somnifera)?
Ashwagandha (Withania somnifera) has a low-med risk profile in the database. Low-Med (hepatotoxicity — emerging case reports since 2020; thyroid hormone elevation — caution in hyperthyroidism or on levothyroxine; sedating; theoretical concerns with autoimmune conditions) Legal status: OTC.
What doses or routes are reported for Ashwagandha (Withania somnifera)?
300-600 mg/day standardized extract (KSM-66 or Sensoril most studied) This is context from studies, approved labeling, clinical practice, or documented use; it is not individualized guidance and does not establish safety.
How does Ashwagandha (Withania somnifera) work?
Ayurvedic 'Indian ginseng'; withanolides (withaferin A, withanolide D); HPA axis modulation — reduces cortisol response to stress; GABAergic; thyroid-stimulating effects

This is an independent synthesis of published research by a non-clinician. Scores are opinions supported by citations, not prescriptions. See the full disclaimer and methodology for how this score was produced and what it does and doesn't mean.