Adaptogen
Ashwagandha
Strong EvidenceMultiple double-blind RCTs and a 2024 meta-analysis (9 RCTs, 558 people) support stress, anxiety and cortisol benefits; strongest for stress/sleep, not memory.
Recommended Dose
600 mg KSM-66 or 300 mg Sensoril daily
Timing
Morning or evening with food
Mechanism of Action
Withanolides modulate the HPA axis, reducing cortisol production. Also acts as a GABAergic anxiolytic and supports thyroid hormone synthesis. May raise DHEA-S and testosterone in men (studied mainly in male-specific trials).
Side Effects & Safety
May cause drowsiness, mild GI upset. Avoid with thyroid medication or autoimmune conditions without medical supervision. Rare liver concerns at very high doses.
Do not use / talk to a doctor first
- Pregnancy and breastfeeding
- Thyroid disease or on thyroid medication
- Autoimmune conditions or on immunosuppressants
- Active or prior liver disease
Interactions
Thyroid hormone medication (e.g., levothyroxine)
May raise thyroid hormones and add to medication — risk of over-treatment
Source: Sharma 2018 (PMID 28829155)
Sedatives / benzodiazepines / alcohol
Additive sedation (GABAergic activity)
Source: MSKCC About Herbs
Immunosuppressants (transplant meds)
May counteract immunosuppression; transplant-rejection case reported
Source: MSKCC About Herbs
Pregnancy & breastfeeding
Avoid during pregnancy and breastfeeding — traditional abortifacient use and a precautionary regulatory contraindication; lactation safety not established.
Who should avoid / see a doctor
Anyone pregnant/breastfeeding, on thyroid, sedative or immunosuppressant medication, or with autoimmune or liver disease. Stop and see a doctor if jaundice, dark urine or unusual fatigue develop.
Synergies
Used in These Stacks
See Ashwagandha inside a full protocol — the stack pages cover when and why to combine it.
Best Products
Partner offers
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References
- 1.Chandrasekhar 2012, Indian J Psychol Med — 600 mg/day root extract for 60 days (n=64) reduced serum cortisol by 27.9% vs 7.9% on placebo, and lowered stress and anxiety scores. (manufacturer-supplied extract)
- 2.Langade 2019, Cureus — Reduced sleep-onset latency and improved sleep efficiency (75.6 → 83.5 over 10 weeks), with lower anxiety. (small sample, n≈58–60)
- 3.Sharma 2018, J Altern Complement Med — 600 mg/day for 8 weeks raised T3 and T4 and lowered TSH — basis for the thyroid-medication interaction.
- 4.EXPLORE (NY) 2024, systematic review & meta-analysis — 9 RCTs, 558 participants; significant reduction on the Perceived Stress Scale (MD −4.72, 95% CI −8.45 to −0.99) — the basis for the Strong rating.
- 5.NIH LiverTox — Ashwagandha (NBK548536) — Likelihood score B (likely cause) of clinically apparent liver injury; latency 2–12 weeks, cholestatic/mixed pattern, usually resolves 1–4 months after stopping; avoid rechallenge. (authoritative body)
- 6.MSKCC — Ashwagandha (About Herbs) — Additive sedation with benzodiazepines/anticonvulsants/barbiturates; thyroid interaction and thyrotoxicosis reports; pregnancy contraindication; a reported kidney-transplant rejection; hormone-sensitive-condition caution. (clinical reference)
