Abstract Summary
Objective
This study aims to identify the specific physiological mechanisms responsible for the subjective "feel-good" effect reported after ashwagandha (Withania somnifera) supplementation, focusing on measurable changes in stress hormones, mood, and steroid hormone levels.
Context
Ashwagandha is an adaptogenic herb used for over 3,000 years in Ayurvedic medicine, with pharmacological studies confirming anti-inflammatory, neuroprotective, adaptogenic, memory-enhancing, hematopoietic, sleep-inducing, and anxiolytic activity. Its "feel-good" reputation is driven by measurable reductions in cortisol and anxiety scores, alongside secondary hormonal shifts, rather than a single mechanism.
Methods Used
Approach
This review draws on a 60-day, randomized, double-blind, placebo-controlled study conducted at two sites in Pune, India (April–July 2016), evaluating a standardized 240 mg/day ashwagandha extract (Shoden) against placebo in 60 healthy adults with self-reported high stress.
Data Collection
Outcomes were measured using the Hamilton Anxiety Rating Scale (HAM-A) and Depression, Anxiety, and Stress Scale-21 (DASS-21), alongside hormonal blood panels tracking cortisol, dehydroepiandrosterone-sulphate (DHEA-S), and testosterone at baseline and study end.
Researchers' Summary of Findings
Impact on Health
Anxiety: Ashwagandha supplementation was associated with a statistically significant reduction in HAM-A scores (P = .040) and a near-significant reduction in DASS-21 scores (P = .096) versus placebo.
Cortisol: Ashwagandha intake was associated with a significantly greater reduction in morning cortisol compared with placebo, supporting the hypothesis that its stress-relieving effects work by moderating the hypothalamus-pituitary-adrenal (HPA) axis.
Testosterone (men only): In the ashwagandha group, testosterone rose by a statistically significant 8% (P = .007). No significant testosterone change occurred in the placebo group.
Health Implications
The "good feeling" reported after taking ashwagandha appears to stem primarily from HPA-axis moderation — lowering the stress hormone cortisol — combined with a direct anxiolytic effect reflected in reduced HAM-A scores. In men, a modest testosterone increase may compound this effect through improved energy and motivation, though this pathway is sex-specific and not the primary driver.
Sustainability
Effects were measured over a 60-day window, meaning benefits build gradually rather than appearing immediately. The authors note that further investigation using larger sample sizes, more diverse clinical/cultural populations, and varying dosages is needed to confirm long-term safety and durability of these effects.
DOI
10.1097/MD.0000000000017186
