How it works
Ashwagandha is a herb used in Ayurvedic medicine. Its active compounds, called withanolides, may influence the body's stress-response system, and several trials report lower cortisol levels and perceived stress. Lower stress and better sleep could indirectly help recovery from training. A few studies in young men doing resistance training report greater increases in strength and muscle size versus placebo, and some suggest small improvements in VO2max, but the mechanisms and consistency of these effects are uncertain.
What research supports
- May reduce perceived stress and anxiety in some trials
- May improve sleep quality in some trials
- Some small studies report modest improvements in strength, muscle size and aerobic capacity
- Some studies report changes in testosterone in men, but evidence is limited
Dosage
Typical research dose: 300–600 mg per day of a standardized root extract, often for 8–12 weeks. Doses and extracts vary considerably between products.
Timing
Studies typically use once- or twice-daily doses with meals. Some people take it in the evening because of possible relaxing effects. Most research does not extend beyond about three months, so long-term use is not well studied.
Side effects
- Stomach upset, diarrhea, drowsiness and headache
- Rare reports of liver injury
Cautions
- Avoid during pregnancy and breastfeeding
- People with thyroid disorders, autoimmune conditions, liver problems, or scheduled surgery should consult a doctor
- May interact with sedatives, thyroid medication, immunosuppressants, and drugs for diabetes and blood pressure
- Herbal products vary in quality and may be contaminated
- Athletes subject to anti-doping rules should only use products certified by an independent third-party testing program for banned substances; certification lowers, but does not eliminate, the risk of contamination.