I’ve used Long R3 IGF-1 along with topical DHT, and found no real benefit in the particular protocol I used (DHT might have some use, but since that’s not what you’re asking about I’ll save that for another thread). I did not inject into the CC though (I think that’s a crazy idea, for which I’ll reason in a moment). I injected into the delts with a 30g pin.
There is fierce debate about IGF-1 being a site specific injection. The majority of people in the debate say “screw the reasons why, it just is, and my results prove it”. I’m one of those people who always asks “why?”. If any other hormone with or without ester is systemic, then why would Long R3 IGF-1 be any different? The only reason I can see that this myth (imho it’s a myth at least) exists, is that IGF-1 on its own without modification, has an extremely short half life, and it would be deactivated before meaningful amounts diffused into the system. With LR3 that is not the case, since it will not bind with IGF-BP1 (a binding protein), and is purported to be active for 12 to 18 hours (though people like Pat Arnold will take issue with that point too).
If you think about what IGF-1 does, then the only real benefit is that it could help you repair more efficiently so you can train more often. In body building the key benefit is hyperplasia, since that does not normally occur in adult muscle tissue. I don’t believe penis growth is IGF-1 dependant in the same way. The ‘claimed’ exceptions are two guys from MOS called Supra and Magnum. I don’t know what to make of their claims since they went quite vague when pushed for details, but nobody else was able to reproduce their results (including CC injection).
As for CC injection, the reason I think it is a crazy idea is that results of surveys taken from regular PGE-1 users indicate that about 9% develop some form of tunical fibrosis at the injection sites. A smaller percentage of those go on to experience peyronies disease. For those that are interested in PGE-1 for erections, you can do it real cheap by using misoprostol tablets dissolved in dmso applied in the urethra, but be warned, it stings like a mofo in the extreme (pass the lidocain!).