Read the book if you haven’t, it’s all in there. You’ll get much more benefit than finding out about the supplements I suspect. I recall something about him introducing himself to people as a drug dealer when asked what he did for a living.

Like the others have said, it's not a secret: it's in his book. He didn't even own the supplement company or anything; he was just a dropshipper.

I believe this was heavily referenced in his original 4-hour work week book, where he describes his early businesses.