Teofimo Lopez Faces Ostarine Scrutiny

- Ostarine, also known as Enobosarm or MK-2866, is a Selective Androgen Receptor Modulator (SARM) designed to mimic the effects of testosterone by binding to androgen receptors in the body to promote muscle growth. It is not approved for human consumption in any country and is banned at all times by the World Anti-Doping Agency (WADA) under the S1 Anabolic Agent category. - The substance is often illegally included in dietary supplements, sometimes without being listed on the label, leading to an increase in positive tests among athletes. Between 2015 and 2017, WADA reported over 100 positive tests for Ostarine globally. - The renewed focus on Lopez follows his controversial February 8, 2024, title defense against Jamaine Ortiz, where he won by unanimous decision. Following the bout, accusations emerged that Lopez had not been subjected to VADA (Voluntary Anti-Doping Association) testing during his training camp. - In response to the allegations, Lopez released a letter from VADA dated February 10, 2024, which stated he had been tested on January 31 of that year and that the results were negative. - This is not the first time a high-profile boxer has faced issues with Ostarine. The substance has been the cause of positive tests for other fighters, raising ongoing concerns about its prevalence and the effectiveness of testing protocols in the sport. - Lopez is scheduled to defend his WBO and The Ring junior welterweight titles against Shakur Stevenson on January 31, 2026, at Madison Square Garden.