Exploring the efficacy and safety of a novel standardized ashwagandha (Withania somnifera) root extract (Witholytin®) in adults experiencing high stress and fatigue in a randomized, double-blind, placebo-controlled trial

J Psychopharmacol. 2023 Nov;37(11):1091-1104. doi: 10.1177/02698811231200023. Epub 2023 Sep 23.


Background: Stress is a state of homeostasis in the body being challenged, resulting in a systemic response. It has become more prevalent in recent years and affects mental and physical health.

Aims: Evaluate the effects of ashwagandha on stress, fatigue, and sex hormones in overweight or mildly obese men and women with self-reported stress and fatigue.

Methods: Two-arm, parallel-group, 12-week, randomized, double-blind, placebo-controlled trial on overweight or mildly obese men and women aged 40-75 years, supplementing with 200 mg of an ashwagandha root extract (Witholytin®) twice daily.

Results/outcomes: Supplementation with ashwagandha was associated with a significant reduction in stress levels based on the Perceived Stress Scale (primary outcome); however, the improvements were not significantly different to the placebo group (p = 0.867). Based on the Chalder Fatigue Scale, there was a statistically significant reduction in fatigue symptoms in the ashwagandha group compared to the placebo group (p = 0.016), and participants taking ashwagandha also experienced a significant increase in heart rate variability (p = 0.003). However, there were no significant between-group differences in other self-report outcome measures. In the men taking ashwagandha, there was a significant increase in the blood concentrations of free testosterone (p = 0.048) and luteinizing hormone (p = 0.002) compared to the placebo group.

Conclusions/interpretation: The results of this study suggest that in overweight middle-to-older age adults experiencing high stress and fatigue, compared to the placebo, ashwagandha did not have a significantly greater impact on perceived stress levels. However, based on secondary outcome measures, it may have anti-fatigue effects. This may be via its impact on the autonomic nervous system. However, further research is required to expand on these current findings.

Keywords: Ashwagandha; Withania somnifera; fatigue; hormones; stress; testosterone.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Double-Blind Method
  • Fatigue / drug therapy
  • Female
  • Humans
  • Male
  • Obesity / drug therapy
  • Overweight
  • Plant Extracts / adverse effects
  • Withania*


  • Ashwagandha
  • Plant Extracts