One of the most consistently vexing problems for fighters competing in the UFC is their relationship with the incredibly shady nutritional supplement industry. While some will debate the necessity for anyone to use supplements on a regular basis, for many athletes training multiple times a day (and looking for any recovery edge they can get) taking pills and powders often seems like a necessity.
Given the highly unregulated nature of the vitamin and supplement market, that puts athletes at a high risk for ingesting products tainted with performance enhancing drugs. Even, as it turns out, when they own the company producing them.