New Delhi: HL September 28, 2026
A large multicentre clinical trial examining the safety of a standardised Ashwagandha root extract over 24 weeks has found no evidence of treatment-related liver or kidney injury among the participants.
The randomised, double-blind, placebo-controlled study involved 1,200 apparently healthy adults aged 18 to 70 years who had received a first, second or booster dose of the COVISHIELD vaccine. The findings were published in Frontiers in Medicine on August 20, 2026.
The study evaluated the safety and tolerability of a standardised aqueous Ashwagandha root extract when taken daily for six months. Researchers reported that liver and kidney function parameters remained within the reported reference ranges throughout the intervention period.
1,200 Adults Participated in the Clinical Trial
Participants were randomly divided into two groups. One group received 500 mg of standardised aqueous Ashwagandha root extract every day, equivalent to approximately 4 grams of raw root powder. The other group received a matching placebo.
The trial was conducted across seven study centres in India, with participants undergoing clinical, laboratory and immunological assessments.
Of the 1,200 people enrolled, 1,032 participants, or approximately 86%, completed the study. The intervention continued for 24 weeks, followed by monitoring through week 28.
No Treatment-Related Liver or Kidney Injury Reported
One of the key objectives was to assess the safety of prolonged Ashwagandha administration.
Researchers monitored several indicators of liver and kidney function, including liver enzymes, bilirubin, creatinine and blood urea.
According to the study findings, these parameters remained within the reported physiological reference ranges, with no evidence of treatment-related hepatic or renal injury during the 24-week intervention.
The researchers also reported that no serious adverse event was considered attributable to the study intervention, and no participant discontinued the trial because of an adverse event.
Ashwagandha and Vaccine-Induced Immunity
The clinical trial also examined whether prolonged administration of the Ashwagandha extract affected the immune response following COVISHIELD vaccination.
The study found that virus-neutralising activity remained high in both the Ashwagandha and placebo groups, with no statistically significant difference between the two groups.
This suggests that the Ashwagandha preparation studied did not adversely interfere with the vaccine-induced immune response. However, the researchers did not establish that Ashwagandha provided an additional immune-enhancing effect.
Study Involved 45 Researchers From Nine Institutions
The research involved a multidisciplinary team of 45 researchers from nine institutions, bringing together expertise in Ayurveda, clinical medicine, rheumatology and complementary and integrative health.
Institutions involved included the Central Council for Research in Ayurvedic Sciences (CCRAS), All India Institute of Ayurveda, National Institute of Ayurveda, Jaipur, Translational Health Science and Technology Institute, Centre for Complementary and Integrative Health and Savitribai Phule Pune University, among others.
The trial was registered with the Clinical Trials Registry–India under CTRI/2021/06/034496.
Researchers Highlight Importance of Standardised Preparations
The researchers said the findings provide additional clinical evidence regarding the safety and tolerability of the specific standardised Ashwagandha preparation used in the trial.
Lead author Dr. Arvind Chopra, Ayush Distinguished Scientist Chair and Director & Chief Rheumatologist at the Centre for Rheumatic Diseases, Pune, said the study provides evidence on the safety of standardised Ashwagandha over a 24-week period and highlighted the importance of evaluating Ayurvedic preparations through well-controlled clinical research.
Prof. Bhushan Patwardhan, National Professor of Ayush and co-author, emphasised the importance of generating contemporary clinical evidence while maintaining the traditional foundations of Ayurveda.
Prof. (Vaidya) Rabinarayan Acharya, Director General, CCRAS, also highlighted the role of well-designed clinical trials in strengthening the evidence base for Ayurvedic interventions.
Findings Do Not Apply to Every Ashwagandha Product
The study’s findings relate specifically to the standardised aqueous Ashwagandha root extract and dosage used in the trial.
Researchers noted that the results should not automatically be extrapolated to every Ashwagandha supplement, extract, formulation or dosage available in the market.
The study was also conducted among apparently healthy adults. Further research may be required to assess the safety and effects of Ashwagandha in elderly populations and people with different medical conditions or other health-related risk factors.
The findings therefore add to the clinical evidence on the safety of a specific standardised Ashwagandha preparation, while also highlighting the need for continued rigorous research into Ayurvedic interventions.
