Supplements that are naturally occurring and have been in the food supply are regulated under the FDA's Generally Recognized As Safe (GRAS) status.

“Right, first of all, most drugs are chemicals, okay? But some are naturally occurring and some are freely available over the counter, OTC. And that's because they've been in our food supply before and the FDA doesn't regulate them. They fall under what's called generally recognized as safe, or GRAS. And that's why you can pick up whole variety of molecules from the plant world, 'cause they're already in our food supply. Therefore the government thinks, well, they're probably okay, even if they're a thousand times more concentrated than what you're eating.”