herb · for anxiety
Ashwagandha
Lowers cortisol by up to a third, and acts on the same calming receptors as your body’s own brake signal.
Say that in clinical terms
Ashwagandha modulates the HPA axis, reducing cortisol levels by up to 30%. Its withanolides act as GABA-mimetics, binding to GABA-A receptors, and also modulate serotonin pathways, producing significant anxiolytic effects.
How strong is the research?
1 paper read, 1 supporting.
Who was studied: Adults aged 22 to 45 scoring high for anxiety and stress — a fair match for most people.
How much to take
daily (split or single dose)
300–600 mg
KSM-66 standardized to 5% withanolides. Can be taken morning and evening. Allow 4-8 weeks for full effect.
Before you take it
- Hepatotoxicity documented in NIH LiverTox (NBK548536): case reports of clinically apparent liver injury including fatal acute liver failure; doses in case reports ranged from 450–1,350 mg/day; withanolides are the prime suspect; avoid in pre-existing liver disease or with concurrently hepatotoxic medications.
- Contraindicated in pregnancy: historically used as an abortifacient; animal studies demonstrate fetal harm; insufficient human safety data to establish a safe dose during pregnancy.
- May elevate thyroid hormones (T3 and T4): avoid in hyperthyroidism or when co-administering thyroid hormone medications.
- Potentiates CNS depressants (benzodiazepines, z-drugs, sedatives, alcohol): additive CNS depression risk.
- In vitro CYP2D6 and CYP3A4 inhibition observed: clinical significance uncertain; flag in any polypharmacy context.
- Immunostimulatory activity: may counteract immunosuppressive therapy in transplant recipients or patients treated for autoimmune disease.
- No established Tolerable Upper Intake Level (UL): NIH ODS has not defined a UL for ashwagandha; long-term safety beyond 8–12 weeks has not been adequately studied in controlled trials.
When to take it
Best taken: evening
What we make of it
Same 64-person study as our stress claim, where anxiety was a secondary finding.
The detail
This rests on the same trial we use for stress. Stress reduction was what it set out to measure; the anxiety improvement was a related secondary result rather than the target.