herb · for irritability
Ashwagandha
Lowers cortisol by up to a third and acts on the brain’s calming system.
Say that in clinical terms
Ashwagandha reduces cortisol by up to 30% and modulates GABAergic signaling, both of which help stabilize mood and reduce stress-induced irritability. It also supports serotonin receptor balance.
How strong is the research?
1 paper read.
Who was studied: Overweight adults under chronic stress, in a weight management trial.
The weakest of our five ashwagandha claims — it came from a weight management trial.
How much to take
daily
300–600 mg
Adaptogenic effects help buffer stress-related irritability. Allow 4-6 weeks for stabilization of mood.
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
The weakest of our five ashwagandha claims — it came from a weight management trial.
The detail
The study was about weight management, and the outcomes it set out to measure were stress and eating behaviour. Irritability was not among them.