That sounds plausible.
Synthol (when done correctly) doesn't add that much size. When done gratuitously, it will deform the muscle, making it look lumpy, gelatinous, and floppy-looking. His delts are still maintaining their shape.
Another possibility is that he is long-ester steroids (like EQ or TC) and repeatedly injecting into the shoulders, adding some temporary local size in a similar effect to synthol, only it will clear a lot faster.
I really don't think as many people take synthol as everyone thinks. The stuff works via its viscosity. It is an extremely viscous substance, like molasses or motor oil or that gravy you sometimes get served atop biscuits at Bob Evans
breakfasts. So when you inject it into the muscle, it stays there for a really long-assed time and never really diffuses. From what I've read about it, a "cycle" would require a regular series of multple injections, very deep into the tissue. You can only add so much in one sitting one sitting because it could cause a tear if you inject too much at once. I really don't think so many guys would go through all that effort, when they could go see a California plastic surgeon and go silicon. Safer, less painful, and heck there's probably a way to get insurance to cover part of it.
