24-Week Trial Finds Standardised Ashwagandha Root Extract Safe, Well Tolerated

A standardised aqueous extract of Ashwagandha root has been found safe and well tolerated over 24 weeks of daily use in a large multicentre randomised controlled trial, with no evidence of treatment-related liver or kidney injury.

The study, published in Frontiers in Medicine on 20 August 2026, was conducted by 45 researchers drawn from nine institutions, including the Central Council for Research in Ayurvedic Sciences (CCRAS), the All India Institute of Ayurveda, the National Institute of Ayurveda in Jaipur, the Ayush Centre of Excellence, the Translational Health Science and Technology Institute, the Centre for Complementary and Integrative Health, and the Interdisciplinary School of Health Sciences at Savitribai Phule Pune University. The team spanned Ayurveda, clinical medicine, rheumatology and complementary and integrative health.

The randomised, double-blind, placebo-controlled trial enrolled 1,200 apparently healthy adults aged 18 to 70 who had received a first, second or booster dose of the COVISHIELD vaccine. Participants were assigned either 500 mg of the standardised aqueous Ashwagandha root extract daily — equivalent to four grams of raw root powder — or a matching placebo. The trial ran across seven sites in India and combined clinical, laboratory and immunological assessments. It was registered with the Clinical Trials Registry–India (CTRI/2021/06/034496).

Participants received the intervention for 24 weeks and were followed through week 28. Of those enrolled, 1,032 — about 86 per cent — completed the study.

Liver and kidney function parameters, including liver enzymes, bilirubin, creatinine and blood urea, remained within reported reference ranges, with no indication of treatment-related hepatic or renal injury. No serious adverse events were attributed to the intervention, and no participant withdrew because of an adverse event.

The trial also examined whether the extract affected immune response after COVISHIELD vaccination. Virus-neutralising activity exceeded 85 per cent in both the Ashwagandha and placebo groups, with no statistically significant difference between them.

Vaidya Rajesh Kotecha, Secretary in the Ministry of Ayush, said high-quality clinical research strengthens the scientific evidence base of Ayurveda and supports its responsible use in contemporary healthcare and wellness settings.

Dr Arvind Chopra, Ayush Distinguished Scientist Chair and Director and Chief Rheumatologist at the Centre for Rheumatic Diseases in Pune, who is the lead author, said the trial offers important evidence on the safety and tolerability of standardised Ashwagandha over 24 weeks. He noted that liver and kidney function stayed within physiological reference ranges, that no treatment-related injury was observed, and that the preparation did not interfere with vaccine-induced immunity, with high neutralising activity maintained in both groups. He added that the results reinforce the value of evaluating standardised Ayurvedic preparations through rigorous, well-controlled research.

Prof. Bhushan Patwardhan, National Professor of Ayush and a co-author, described the work as an example of evaluating Ayurveda through robust contemporary clinical research while retaining its traditional foundations, and said the findings add to the clinical evidence on standardised Ashwagandha preparations.

Prof. (Vaidya) Rabinarayan Acharya, Director General of CCRAS, said the trial provides valuable evidence on the safety and tolerability of the standardised root extract under controlled conditions over 24 weeks, and that such well-designed studies help strengthen the scientific basis for the evidence-informed use of standardised Ayurvedic preparations.