24-Week Ashwagandha Clinical Trial Safety Results
A large multicenter clinical study published in Frontiers of Medicine on August 20, 2026, has demonstrated that daily administration of standardized Ashwagandha root extract for 24 weeks was well tolerated with no evidence of treatment-related liver or kidney injury. The randomized, double-blind, placebo-controlled trial involved 1,200 apparently healthy adults aged 18-70 years who had received first, second, or booster doses of COVISHIELD vaccine, with participants randomly assigned to receive either 500 mg of standardized aqueous Ashwagandha root extract daily (equivalent to 4 grams of raw root powder) or a matching placebo.
The study was conducted by a multidisciplinary team of 45 researchers from 9 institutions including the Central Council for Research in Ayurvedic Sciences (CCRAS), All India Institute of Ayurveda, National Institute of Ayurveda Jaipur, and Savitribai Phule Pune University. The trial was conducted across seven study sites in India and included clinical, laboratory, and immunological assessments, registered with Clinical Trials Registry-India (CTRI/2021/06/034496).
Of the 1,200 participants enrolled, 1,032 (86%) completed the 24-week intervention period with follow-up through week 28. Liver and kidney function parameters remained within reported reference ranges throughout the study, with assessments including liver enzymes, bilirubin, creatinine, and blood urea showing no evidence of treatment-related hepatic or renal injury. No serious adverse events were considered attributable to the study intervention, and no participant withdrew from the trial due to an adverse event.
The study also assessed the effect of the 24-week administration on immune response following COVISHIELD vaccination, finding that virus-neutralizing activity exceeded 85% in both the Ashwagandha and placebo groups with no statistically significant difference between groups, indicating that Ashwagandha did not interfere with vaccine-induced immunity.
Vaidya Rajesh Kotecha, Secretary of the Ministry of Ayush, emphasized that these findings contribute to robust scientific evidence supporting the safety and appropriate use of standardized Ayurveda interventions. Dr. Arvind Chopra, lead author of the study, highlighted that the trial provides important evidence on the safety and tolerability of standardized Ashwagandha over 24 weeks, while Prof. Bhushan Patwardhan emphasized the significance of generating high-quality evidence for Ayurveda through contemporary clinical research.