Written by Tabish Mehraj, PhD, Science Writer. In this study, ashwagandha supplementation led to a significant reduction in BMI (3.31 kg/m²) and weight loss (8.46 kg) compared with placebo; it also helped reduce stress (PSS-10), improved quality of life, and controlled food cravings. Serum cortisol levels decreased by 36%; the treatment was well tolerated, with mild side effects.

The relationship between an individual’s weight gain and psychological stress is well established. Increased stress levels result in weight gain primarily due to elevated cortisol (a stress hormone). Ashwagandha is a well-known herbal remedy known for enhancing cognitive function and for its antioxidant properties. This study, conducted by Ketan Pakhale and his team at a single center in Mumbai, India, investigated whether supplementation with ashwagandha root extract (ARE) could safely reduce stress, improve well-being, and support weight management in overweight adults. The likely mechanism involves modulation of the HPA axis, reduction of cortisol secretion, and attenuation of stress-induced appetite and emotional eating behaviors. ARE’s adaptogenic, antioxidant, and neuroregulatory effects may also help improve neurotransmitter balance and reduce markers of inflammation and oxidative stress, leading to overall psychological and metabolic stabilization.

In this prospective, randomized, double-blind, placebo-controlled clinical study, 100 adults aged 19–65 years were enrolled, with a BMI of 25–39.9 kg/m². Subjects were divided into groups to receive either standardized ashwagandha root extract (KSM-66®, 300 mg twice daily; n = 50) or a placebo (n = 50). The enrolled adults were asked to maintain their lifestyle by following a proper diet and exercising. The main objectives that were studied were changes in BMI and body weight from baseline to week 24. The other parameters that were studied were quality of life (SF-12 survey), changes in perceived stress (Perceived Stress Scale-10, PSS-10), food cravings (Food Cravings Questionnaire-Trait, FCQ-T), and subjective satisfaction (SSS). The safety parameters included treatment-emergent adverse events (TEAEs) and a broad panel of assessments covering hepatic, hematological, renal, glycemic, lipid, and thyroid parameters, as well as serum cortisol, a key biomarker of stress.

Results/ Key Findings

BMI and Weight Loss Reduction: The ashwagandha intervention group lost 8.46 kg vs 2.41 kg for placebo, and BMI decreased from 3.31 kg/m² vs −0.93 kg/m² (P < 0.0001; large effect size, Cohen’s d = 1.919).

Overall Well-Being and Stress Reduction: The observed stress scores dropped more in the ashwagandha group (6.16 vs 1.43), quality of life improved (+9.38 vs +2.54), and overall satisfaction increased (9.42 vs 3.65) compared to placebo (all P < 0.001).

Behavioral Benefits and Food Craving Control: A significant decrease was observed for the total FCQ-T scores (21.24 vs 8.28).

Reduced Physiological Stress: Serum cortisol dropped by 36% in the ashwagandha group (13.91 → 8.90 μg/dL) vs a smaller reduction in placebo, confirming stress-lowering effects (P = 0.006; Cohen’s d = 0.595).

Good Safety Profile: No serious adverse effects were observed, aside from nausea and abdominal pain. The lab tests were normal, with metabolic improvements observed at week 12.

The trial’s findings strongly support ashwagandha’s dual role in stress reduction and weight management. Over 24 weeks, supplementation with 600 mg/day of standardized ashwagandha root extract (KSM-66®) led to significant, sustainable decreases in body weight, BMI, perceived stress, cortisol levels, and food cravings. The detailed laboratory safety monitoring confirmed ARE’s excellent tolerability profile and metabolic neutrality.

While this is a single-center study, several limitations need to be considered. The results of this study depict only a small group of individuals; therefore, they may not be broadly generalizable to other populations or cultural contexts. In addition, food habits, sleep quality, and physical activity were not thoroughly monitored. Unevenness in these factors may influence weight changes and stress-related responses in certain individuals. Furthermore, this study did not include an assessment of additional neuroendocrine and inflammatory biomarkers, which can further clarify underlying mechanisms. Since the follow-up period was restricted to only 24 weeks, extended investigations are required to assess the sustainability of the observed effects.

This clinical trial determined that the standardized ashwagandha root extract (KSM-66®, 300 mg twice daily) is potentially effective, safe, and well-tolerated for managing stress and weight gain in adults. ARE exhibited statistically significant and clinically meaningful changes in body weight, BMI, perceived stress, food cravings, quality of life, and serum cortisol, without notable adverse events or laboratory abnormalities.

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Posted May 15, 2026.

Dr. Tabish Mehraj is a pharmaceutical scientist with expertise in pharmaceutics, drug delivery, and formulation development. She earned her PhD in Pharmaceutical Sciences from the University of Mississippi, where her research focused on the formulation, optimization, and characterization of lipid-based nanocarriers for targeted liver delivery of antimalarial therapeutics. Dr. Mehraj has also served as an ORISE Fellow at the U.S. Food and Drug Administration (FDA), where she evaluated the effects of formulation and process design on the quality and performance of intravaginal drug delivery systems and developed bio-relevant in vitro drug release testing methods. She has teaching experience in pharmaceutical and life sciences courses and has authored peer-reviewed publications, book chapters, and conference presentations. Dr. Mehraj is an active member of the American Association of Pharmaceutical Scientists and has been recognized by honor societies including Rho Chi and Gamma Beta Phi.

References:

1. Pakhale, K., Pakhale, R., Srivathsan, M., Langade, J., & Langade, D. (2025). Efficacy and safety of Ashwagandha (Withania somnifera) root extract on stress and weight management in adults: a prospective, randomized, double-blind, placebo-controlled study. Journal of Medicine and Life, 18(12), 1140.