Background

Ashwagandha (Withania somnifera) is a herb commonly used in Ayurvedic medicine to promote youthful vigor, enhance muscle strength and endurance, and improve overall health. In this 16-week, randomized, double-blind, placebo-controlled, crossover study, its effects on fatigue, vigor, and steroid hormones in aging men were investigated.

Methods

Overweight men aged 40–70 years, with mild fatigue, were given a placebo or an ashwagandha extract (Shoden beads, delivering 21 mg of withanolide glycosides a day) for 8 weeks. Outcome measures included the Profile of Mood States, Short Form (POMS-SF), Aging Males’ Symptoms (AMS) questionnaire, and salivary levels of DHEA-S, testosterone, cortisol, and estradiol. Fifty-seven participants were enrolled, with 50 people completing the first 8-week period of the trial and 43 completing all 16 weeks.

Results

Improvements in fatigue, vigor, and sexual and psychological well-being were reported over time, with no statistically significant between-group differences. Ashwagandha intake was associated with an 18% greater increase in DHEA-S (p = .005) and 14.7% greater increase in testosterone (p = .010) compared to the placebo. There were no significant between-group differences in cortisol and estradiol.

Conclusions

In conclusion, the intake of a standardized ashwagandha extract (Shoden beads) for 8 weeks was associated with increased levels of DHEA-S and testosterone. Further studies with larger sample sizes are required to substantiate the current findings.