TweetOk, fact is, you CAN inject slin into muscles, it just changes the pharmakinetics. I believe the slin needle is about the right length for a bicep injection. A person could do 5 I.U. in each bicep after a serious bicep workout. My theory for this is that it is recommended to rotate injection spots with slin in the stomach so that there is not a tissue buildup (of fat). Couldn't this same principle be used for biceps, i.e., more slin is delivered to where it is injected. Any thoughts?? Anyone willing to try?? I would but don't want to guinea pig when I've never used Slin.