So bulleyez, you're a gangsta who wants to be gangsta lean?
Here's what it is:
You take the T3 (pills, not the movie), and it makes your metabolism speed up fast and shit. That's all good.
Problem is that the thyroid in your body doesn't jive with all that. You have thyroid produced in your body, and it pretty much says fuck it, and quits representing. Then you gotta stay on the T3 for the rest of your life. Kinda like gettin' a cap busted in your head but from the inside.
If you don't take the thyroid from there on out, you turn into Tony Rocky Horror.
Definitely not what you may call 'the shiznit'.