Define "unnatural" though? That opens a whole nother can of worms. I'd bet there aren't many elite fighters who don't take some kind of supplement which doesn't exactly grow on trees. If it legit wasn't banned and he stopped taking it when it became so, then he shouldn't be punished imo. For the record, I don't doubt he was also taking other things which weren't detectable, and I wouldn't doubt Wilder is/was also.