herb · for stress
Ashwagandha
Lowers cortisol, your main stress hormone, by roughly a quarter in trials.
Say that in clinical terms
Ashwagandha is a premier adaptogen that modulates the HPA axis, reducing cortisol secretion by 23-30%. It mimics GABA at GABA-A receptors and enhances stress resilience through BDNF upregulation and neuroprotection.
How strong is the research?
1 paper read, 1 supporting.
Who was studied: Working adults aged 22 to 45 who scored high on a stress questionnaire — a close match for most people.
How much to take
daily (split AM/PM)
300–600 mg
The most studied adaptogen for stress. KSM-66 is the best-studied extract. Take consistently for best results.
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
Nearly every trial of this branded extract is funded by the company that sells it.
The detail
Several small trials do show cortisol and stress scores falling. Almost all of them are sponsored or supplied by the branded extract’s manufacturer, which counts around 70 affiliated studies and dominates funding in this area. That does not make the results wrong, but one company producing nearly all the evidence is worth knowing.