France: ANSES Warns of Severe Health Risks Linked to Excessive Sports Supplement Use

The French Agency for Food, Environmental and Occupational Health & Safety (ANSES) has published an opinion concerning a severe case of liver and kidney damage associated with the excessive consumption of two sports nutrition supplements: Isostar Mass Gainer and Eafit Pure Whey. The case involved a consumer who developed decompensated cirrhosis, acute renal failure and ultimately required a liver transplant.

Following an investigation launched in October 2025, ANSES concluded that the adverse effects were very likely linked to the supplements, with causality assessed as highly probable for cirrhosis and probable for kidney injury. Experts identified excessive intake of vitamin B3 (niacin) and vitamin A, both known for their hepatotoxic potential, as likely contributors. High protein intake and the simultaneous consumption of multiple supplements above recommended doses may also have played a role.

The agency stressed that food supplements are not without risk and reiterated the importance of following manufacturers’ instructions and avoiding the concurrent use of several supplements without professional advice. ANSES also encouraged consumers and healthcare professionals to report suspected adverse effects through the French nutrivigilance system.