Does different pin size affect absorption?

[adamryi]

I've never heard of a BB'er ending their career because of scar tissue....no matter what pin size those guys are using the hell out of their bodies and I never hear any pro BB'er talk to complain about it. Even the ones that are open about their use.

That point is irrelevant. What bodybuilder who puts themselves through hell in the gym is going to complain about scar tissue let alone end their career. There are ways to reduce or break up scar tissue (ART massage, surgery etc). Mike Arnold isn't saying that its the end of the world to use bigger size needles, its just beneficial to use smaller needles to accumulate less scar tissue over time especially if you plan on using for years on end. Honestly, Mike Arnold is giving you GOLDEN advice. Take it or leave it