The China Anti-Doping Agency (CHINADA) has criticized the US Anti-Doping Agency (USADA) for alleged double standards following the positive doping test of US sprinter Erriyon Knighton for trenbolone, a banned steroid, which was dismissed as meat contamination. CHINADA questioned why USADA had not warned athletes about trenbolone contamination in meat and highlighted the exoneration of three US athletes under similar claims. Tensions between global anti-doping bodies have increased, with the World Anti-Doping Agency (WADA) criticizing USADA for using undercover athletes without prosecution, which violates global anti-doping codes. The ongoing dispute is exacerbated by past incidents, such as the clearance of 23 Chinese swimmers for a different banned substance, trimetazidine, before the Tokyo Olympics. These controversies reflect broader geopolitical tensions and differing approaches to anti-doping enforcement. USADA defends its tactics as necessary for tackling systemic doping issues, while CHINADA accuses the US of political manipulation and hypocrisy.