Synthols is not the only substance being used right now to enhance the appearance of muscle mass. There are synthetics materials like "biopolymer" being used on muscles, mainly Brazilian women on their ass, but some BBers are shooting it too.
I really have no idea about Rich Piana or what he uses, but the dude is extremely massive dude. That kind of size needs a lot of hard work and dedication, no matter what you use to help you, the guys has to bust his ass in the gym daily to get there.
(Nice to see you back around TS!)