I see little reason to think Bezos is on any sort of enhancement. He previously looked like he'd literally never worked out in his life, and probably also had a horrible diet. Put somebody like that in the gym with a proper diet and routine, and they're just going to blow up fast, even when starting late. Most people can't do it for lack of self discipline, but that's one thing he seems to have no lack of. And no idea what people are saying about Musk. He just seems like a typical yo-yo dieter with a hair transplant.

Also, it's relevant that Bezos is one of the guys blowing money on life extension tech. So I think there's 0 chance he sees anabolics (or other enhancements) as a good risk:reward when he certainly fantasizes about there being a possibility of life extension happening within his lifetime.