Ashwagandha has become increasingly popular as an Ayurvedic supplement, with many people using it for stress management, sleep and general wellness. However, concerns have also been raised about whether long-term use could affect the liver or kidneys.

A recent clinical trial has provided encouraging findings. Published in Frontiers in Medicine, the study found no evidence of treatment-related liver or kidney damage among participants who consumed a standardized ashwagandha root extract for 24 weeks.

However, the findings should be understood in context: the study evaluated a specific standardized extract and dose, so they should not automatically be applied to every ashwagandha product available in the market.

What did the study examine?

The large clinical trial was conducted across seven research centres in India and included 1,200 participants. They were divided into two groups.

One group received 500 mg of a standardized, gelled ashwagandha root extract every day, equivalent to about 4 grams of raw ashwagandha root powder. The second group received a placebo designed to look identical.

Participants took the assigned product for 24 weeks and were subsequently monitored until week 28. Their health was assessed through clinical examinations and laboratory tests.

Of the 1,200 participants, 1,032 completed the study.

What happened to liver and kidney function?

Researchers monitored several markers of liver and kidney health throughout the trial.

According to the study, liver enzymes and bilirubin remained within normal reference ranges. Kidney-related parameters, including creatinine and blood urea, also showed no evidence of treatment-related injury.

The researchers reported no serious adverse events considered related to the study intervention, and no participant discontinued the trial because of adverse effects.

These findings suggest that the particular standardized ashwagandha extract studied was generally well tolerated over the 24-week period.

Did ashwagandha affect vaccine-related immunity?

The researchers also examined whether ashwagandha supplementation affected the immune response following Covishield vaccination.

Virus-neutralizing activity remained above 85% in both the ashwagandha and placebo groups. Researchers found no statistically significant difference between the two groups.

The study therefore found no evidence that the standardized extract interfered with the vaccine-induced immune response.

A large research team was involved

The trial involved 45 researchers from nine institutions working across areas including 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 in Jaipur, Translational Health Science and Technology Institute and Savitribai Phule Pune University.

The trial was registered with the Clinical Trials Registry-India under CTRI/2021/06/034496.

What do the findings mean for people taking ashwagandha?

The results are encouraging, particularly because the trial was randomized, controlled and conducted across multiple centres.

However, the findings do not mean that every ashwagandha supplement is automatically safe for everyone. Different products can contain different extracts, concentrations, ingredients and levels of standardization.

People who take medicines regularly or have existing liver or kidney problems should consult a healthcare professional before starting an herbal supplement.

Ayurveda and modern research

Researchers involved in the study emphasized that traditional Ayurvedic products can be evaluated using modern clinical research methods. They said that well-designed trials can help establish clearer evidence regarding the safety and appropriate use of standardized Ayurvedic preparations.

Overall, the study provides reassuring evidence about the 24-week use of the specific standardized ashwagandha extract that was tested. At the same time, continued research is needed to understand its safety with longer-term use and across different formulations.