
On November 15, 2025, VADA notified WBC World Super Lightweight Champion Subriel Matías and the WBC of an adverse analytical finding consistent with the presence of Ostarine in a urine sample collected from him on November 9, 2025.
Several anti-doping result management authorities have set thresholds for the presence of Ostarine under which an Ostarine positive result is not considered an adverse finding. Findings under the threshold are considered atypical, whereupon the athlete is cleared after a cursory review. For example, the New York State Athletic Commission, which is the jurisdiction where the upcoming Matías v. Dalton WBC World Championship bout will take place, does not consider a concentration below 0.1 ng/ML to be an adverse finding. The reported concentration of Ostarine in Champion Matías’ sample was 0.085 ng/mL, which is below that threshold.
The WBC conducted an expedited but thorough investigation following the prescriptions of its Clean Boxing Program protocol. Champion Matías and his team were fully cooperative with every aspect of the process. The process concluded with the WBC and champion Matías entering into an Adjudication Agreement which requires Champion Matías to be subjected to and comply with the following conditions:
A. Probation for one (1) year from the date of the sample collection;
B. Undergo additional random anti-doping testing during the probationary period at his own expense;
C. Participate in a nutrition education program designed and conducted by the WBC Nutrition Committee;
D. Participate in social responsibility activations such as visiting boxing gyms to speak about the dangers of consuming potentially contaminated nutritional supplements; and
E. Be suspended indefinitely without further inquiry if a sample collected from him results in an adverse finding during his probationary period.
Unfortunate, inaccurate, and speculative information was reported last week regarding Champion Matías when the results of his Sample B became available. It is important that the public recognizes that, in the anti-doping testing context, B Sample results are overwhelmingly the same the A sample ones. The contents of the A Sample container and those of the B Sample one are exactly the same. The testing of the B Sample contents is just confirmatory of the A Sample one. The B Sample test results, therefore, do not represent a new or additional adverse finding nor a new violation of any rules.
During its annual convention, the WBC ruled to modify the Clean Boxing Program Protocol. The modifications are necessary due to the fact that there is a definite link between most of the adverse finding results and actual or alleged contamination of supplements boxers use. The WBC will publish and implement its new Clean Boxing Program Protocol starting in February of 2026.
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