My opinion probably doesn't count for much because it's not based on any degree of knowledge about how synthol or site injections work, just my own deductive reasoning, flawed as it may be.
It just seems like if Gregg was going to lie about his arms he could come up with something better, like they just got that way from juicing and training. I mean, he admits he injected them with equipoise (I think that's what he says) thousands and thousands of times over a period of many years, so why is that so different from injecting them with synthol?
It's not like he's saying he built them through good old-fashioned hard work or anything, he admits he fcuked with them over years and years to get them like that. That's why I don't find his story so hard to believe.