Clinical Study on Ashwagandha

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

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).

Conflict of interest statement

This study was independently managed by the principal investigators, Dr HM and RK, who declare no competing interests. Dr AL has received study funding from Arjuna Natural Extracts Ltd in the past for previously completed unrelated studies and has received compensation for conference presentations. The authors have no conflicts of interest to disclose.

 

Figures