One other thing… the first time I gave myself an injection I did it with a 21 g Human Chorionic Gonadotropin (HCG) mixing pin right in the quad. STUPID! That f-ing hurt and made a slight crunch sound. Please do not do that. LOL. I would not use anything larger than 25g in the leg and 23g in the back side. Having one to draw and one to inject makes a big difference too.