Body modification is an interesting psychology. Tattooing and piercing is now quite mainstream, in fact, it's passé, saying nothing about the individual now, other than they are a follower.
I was a headbanger, part of a subculture where tattoos and piercings were quite prevalent when they were still seen as rebellious. I never got one, because I'm an individual, even as part of a subculture.
Tanning is now just more following. Don't get me wrong, I have nothing against real tanning (I'm a surfer), but fake tans are some aspirational BS. Same as a large number of tattoos or piercings let you know the individual is unsatisfied with their lot in life. The question is, 'when will they be happy?' When they can tan no more/look no more like the celeb they idolise, or have no skin left unetched, in the case of body modders? (do you think this guy is happy?
http://www.lyzyrdgyzyrd.com/images/piercings.jpg )
On ACTH, a quick google looks like there could be some similar reactions taking place, yes. As this stuff is a hormone, people have to be rather dense, or optimistic to go injecting it. Upsetting hormone balance is bound to have side effects.