Clinical trial finds no evidence of liver or kidney injury from standardised Ashwagandha extract
A multicentre trial involving 1,200 adults found a standardised Ashwagandha root extract was well tolerated over 24 weeks, with no treatment-related liver or kidney injury reported.
The research involved 45 researchers from nine institutions and was conducted across seven study sites in India.
NEW DELHI: A large multicentre clinical trial involving 1,200 adults has found that daily use of a standardised Ashwagandha root extract for 24 weeks was well tolerated, with researchers reporting no evidence of treatment-related liver or kidney injury.
The randomised, double-blind, placebo-controlled study was published in Frontiers in Medicine on August 20, 2026. It examined the prolonged use and tolerability of Ashwagandha following COVISHIELD vaccination.
The research involved 45 researchers from nine institutions and was conducted across seven study sites in India. Participating institutions included the Central Council for Research in Ayurvedic Sciences (CCRAS), All India Institute of Ayurveda, National Institute of Ayurveda in Jaipur, Translational Health Science and Technology Institute and Savitribai Phule Pune University, among others.
Researchers enrolled 1,200 apparently healthy adults aged between 18 and 70 who had received a first, second or booster dose of COVISHIELD.
Participants were randomly assigned either 500 mg of a standardised aqueous Ashwagandha root extract daily — equivalent to four grams of raw root powder — or a matching placebo. They received the intervention for 24 weeks and were followed until week 28. Of those enrolled, 1,032 participants, or 86%, completed the study.
The trial included clinical, laboratory and immunological assessments and was registered with the Clinical Trials Registry–India under CTRI/2021/06/034496.
Researchers reported that liver and kidney function parameters remained within the reported reference ranges during the intervention. Tests included liver enzymes, bilirubin, creatinine and blood urea, with the study finding no evidence of treatment-related hepatic or renal injury.
No serious adverse events were considered attributable to the intervention, while no participant withdrew from the trial because of an adverse event, according to the study.
The researchers also examined whether Ashwagandha administration affected the immune response following COVISHIELD vaccination. Virus-neutralising activity exceeded 85% in both the Ashwagandha and placebo groups, with no statistically significant difference between them.
Dr Arvind Chopra, Ayush Distinguished Scientist Chair and Director and Chief Rheumatologist at the Centre for Rheumatic Diseases, Pune, and lead author of the study, said the findings provided evidence on the safety and tolerability of the standardised preparation over the 24-week study period.
He said the findings also indicated that Ashwagandha did not interfere with vaccine-induced immunity under the conditions examined in the trial.
Vaidya Rajesh Kotecha, Secretary, Ministry of Ayush, said high-quality clinical research was important for strengthening the scientific evidence base of Ayurveda and supporting the responsible use of Ayurvedic interventions in healthcare and wellness settings.
Prof. Bhushan Patwardhan, National Professor of Ayush and a co-author of the study, said the research demonstrated how Ayurvedic interventions could be evaluated using contemporary clinical research methods while retaining their traditional foundations.
CCRAS Director General Prof (Vaidya) Rabinarayan Acharya said well-designed clinical trials were important for generating evidence on the safety and tolerability of standardised Ayurvedic preparations.
The findings apply specifically to the standardised aqueous Ashwagandha root extract, dose, participant population and 24-week treatment period examined in the trial. The study primarily assessed safety and tolerability rather than establishing Ashwagandha as a treatment for a particular disease.
