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@Onetrickpony said... There is a big list of things that are proven to be historically clean available. Jeff Novitzky mentioned on the Rogan Podcast that if someone is going to use a supplement then they need to be careful with what they buy. If it says it's 3rd Party tested then even if proven to have something in it after the fact, the fighter will most likely get a slap on the wrist because they did what they could as far as choosing as wisely as they can based on the info available.
If someone, I'm looking at you Jon Jones, buys something online from a site that also sells super shady shit then you're going to have a hard time getting off without a suspension.