The clinical study titled ‘Safe prolonged prophylactic use and tolerability of Ashwagandha following COVISHIELD™ vaccination over 24 weeks: a multicenter randomized double-blind placebo-controlled trial’ was published on 20 August, 2026 in Frontiers in Medicine.
The clinical trial was randomized, double-blind, placebo-controlled and multi centered. Researchers from 9 institutions conducted the study. Around 45 multidisciplinary experts monitored the trial across various sites, bringing together expertise across ayurveda, clinical medicine, rheumatology, complementary and integrative health and related disciplines.
The Ayush Ministry funded study was conducted across seven study sites in India and included clinical, laboratory and immunological assessments. The trial was registered with the Clinical Trials Registry–India.
1,200 healthy adults aged between 18 to 70 years were recruited for the study. The recruitment criteria included that participants should have received a first, second or booster dose of the COVISHIELD vaccine.
Participants were randomly assigned to receive either 500 milligrams of a standardized aqueous Ashwagandha root extract daily, equivalent to four grams of raw root powder, or a matching placebo. The intervention continued for 24 weeks, with participants followed up until week 28.
Out of the 1,200 recruited participants, 1,032 completed the study. The participants were closely monitored for 24 weeks by ‘comprehensive clinical and laboratory assessment’.
Vaidya Rajesh Kotecha, Secretary, Ministry of Ayush said that “High-quality clinical research strengthens the scientific evidence-base of Ayurveda and contributes to a deeper understanding of its potential within contemporary healthcare. The growing body of evidence from rigorous clinical studies is also supporting the responsible global utilization of Ayurveda and its interventions across health and wellness settings.”
In a randomized approach, the participants are randomly divided into two groups. One is the treatment group receiving the investigational drug, and the other is the control group receiving a placebo.
Double-blind clinical trials are the ones where neither the participants nor the researchers know who is receiving the investigational drug or placebo.
A placebo is something that resembles the new drug without its active therapeutic ingredient. It is identical to the investigational drug, such that people assume it's the actual medicine.
A placebo is used as a comparison to determine whether the treatment is itself responsible for an observed effect.
The clinical trials that administer the use of Placebo are hence labelled placebo controlled.
The trial reported 86% retention after randomization, and high completion of clinical data. The ministry reported zero serious adverse events, attributable to the study intervention. Adverse events were predominantly gut related and mild, and none caused withdrawal; zero participants withdrew from the trial because of an adverse event.
The study concluded with a favorable safety and tolerability profile for the standardized Ashwagandha root extract over the 24-week intervention period.
Liver and kidney function parameters remained within the normal ranges. The assessments included liver enzymes, bilirubin, creatinine and blood urea showing no evidence of treatment-related hepatic or renal injury.
Dr. Arvind Chopra, Ayush Distinguished Scientist Chair and Director & Chief Rheumatologist at the Centre for Rheumatic Diseases, Pune, India, who is also the lead author of the study, highlighted the significance of the findings, stating, “This large, multicenter, randomized clinical trial provides important evidence on the safety and tolerability of standardized Ashwagandha over 24 weeks. Throughout the study, liver and kidney function parameters remained within physiological reference ranges, with no treatment-related liver or kidney injury observed.”
The study also demonstrated that Ashwagandha did not interfere with vaccine-induced immunity, with high levels of neutralizing activity maintained across both the Ashwagandha and placebo groups. These findings reinforce the importance of evaluating standardized Ayurvedic preparations through rigorous, well-controlled clinical research.Dr. Arvind Chopra, Rheumatologist, Centre for Rheumatic Diseases, Pune, India
It is well known that Ashwagandha is safe for short-term use for people who are generally healthy. However, data on use beyond three months is limited.
Some people who take ashwagandha experience mild side effects. These can include loose stools, nausea, or drowsiness. In rare instances, ashwagandha has also been reported to cause liver injury, impaired liver function, or both.
According to an article published by Harvard Medical School, Ashwagandha may also interact with medications used to treat
Anxiety
Autoimmune conditions
Diabetes
High blood pressure
Seizures
Sleep
Thyroid disease
Keep in mind that ashwagandha may not work for everyone. Many people find that the herb helps them feel calmer and less stressed. But anecdotally, some people report feeling more stimulated or anxious.
Since resources are very limited on the use of Ashwagandha, the study sponsored by the health ministry helps us get to know about the herb a little more. The purpose of clinical trials is to gather as much evidence and data as possible and research is always encouraged, especially in cases like these where little is known about the investigational drug.
(Rh/MF/MSM)