An investigation into the stress-relieving and pharmacological actions of an ashwagandha (Withania somnifera) extract: A randomized, double-blind, placebo-controlled study

Medicine (Baltimore). 2019 Sep;98(37):e17186. doi: 10.1097/MD.0000000000017186.

Abstract

Background: Ashwagandha (Withania somnifera (L.) Dunal) is a herb traditionally used to reduce stress and enhance wellbeing. The aim of this study was to investigate its anxiolytic effects on adults with self-reported high stress and to examine potential mechanisms associated with its therapeutic effects.

Methods: In this 60-day, randomized, double-blind, placebo-controlled study the stress-relieving and pharmacological activity of an ashwagandha extract was investigated in stressed, healthy adults. Sixty adults were randomly allocated to take either a placebo or 240 mg of a standardized ashwagandha extract (Shoden) once daily. Outcomes were measured using the Hamilton Anxiety Rating Scale (HAM-A), Depression, Anxiety, and Stress Scale -21 (DASS-21), and hormonal changes in cortisol, dehydroepiandrosterone-sulphate (DHEA-S), and testosterone.

Results: All participants completed the trial with no adverse events reported. In comparison with the placebo, ashwagandha supplementation was associated with a statistically significant reduction in the HAM-A (P = .040) and a near-significant reduction in the DASS-21 (P = .096). Ashwagandha intake was also associated with greater reductions in morning cortisol (P < .001), and DHEA-S (P = .004) compared with the placebo. Testosterone levels increased in males (P = .038) but not females (P = .989) over time, although this change was not statistically significant compared with the placebo (P = .158).

Conclusions: These findings suggest that ashwagandha's stress-relieving effects may occur via its moderating effect on the hypothalamus-pituitary-adrenal axis. However, further investigation utilizing larger sample sizes, diverse clinical and cultural populations, and varying treatment dosages are needed to substantiate these findings.

Trial registration: Clinical Trials Registry-India (CTRI registration number: CTRI/2017/08/009449; date of registration 22/08/2017).

Publication types

  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Anti-Anxiety Agents / adverse effects
  • Anti-Anxiety Agents / therapeutic use*
  • Anxiety / drug therapy*
  • Anxiety / metabolism
  • Dehydroepiandrosterone Sulfate / metabolism
  • Double-Blind Method
  • Female
  • Humans
  • Hydrocortisone / metabolism
  • Male
  • Phytotherapy
  • Plant Extracts / adverse effects
  • Plant Extracts / therapeutic use*
  • Stress, Psychological / drug therapy*
  • Stress, Psychological / metabolism
  • Testosterone / metabolism
  • Treatment Outcome

Substances

  • Anti-Anxiety Agents
  • Plant Extracts
  • Testosterone
  • Dehydroepiandrosterone Sulfate
  • Ashwagandha
  • Hydrocortisone