Someone testing on themselves is how we learned what causes and how to treat ulcers (the researcher earned a Nobel prize for giving himself an ulcer, and then treating it), among other things.
Controlled trials are great, but research has to start somewhere.
I think to be fair, you’ve got to compare his before and after, rather than comparing him to anyone else.
I certainly wouldn’t say he looks young, but I think he’s on a better trajectory.