There is no difference like BB said. I noticed this guy knows a lot about training and everything related.
The problem is that half the time it's the wrong hormone. There's a bigger chance they're the wrong hormone than most common steroids cooked up by UG labs.
No one is inventing any prohormones really. Nor are they knew and first syntheized by the supp company. They simply look up hormones in a book by a guy named Vida.
Mos of this stuff was never really legal. Notice how the bigger companies will not touch the prohormone stuff, but those would make a crazy amount of money because they are anabolic steroids.
