Testosterone cypionate is the hands down winner of any testosterone therapy out there on the Peak Testosterone Forum. Guys enjoy the predictability and the fact that they can self-inject. It's nice to have a little control over something in your life, eh?
However, one question that comes up is whether or not subcutaneous or intramuscular injections are better. In my opinion, there is not much difference between the two, assuming you are injecting equal amounts with equal frequency. But there are men who would beg to differ. (SubQ is never injected weekly as far as I know.)
I am going to leave that aside now, though and try to answer as to where the best place(s) arefor a man to self-inject IM (intramuscular) cypionate? And I bring up self-injection, because very few doctor's offices or TRT clinics require their patients to come in for an injection any more.
There are basically three subcutaneous injuection site choices and, no, this is not rocket science::
a) Stomach Fat Pad Area. Most of us men, even if pretty lean, will have a little "band" of fat around our midsection near the navel. 95+% of men can inject subQ (subcutaneously) into this area, typically between 1 and 3 inches to the side of the navel. This is where I and most subQ guys inject. It's easy. It's reachable. It's visible, etc.
NOTE: Subcutaneous refers to injecting in the fat layer just below the skin. Needles are shortler than intramuscular (and often thinner): 5/16 or 1/2 inch.
b) Love Handles. Time to put those love handles to a second good use? Again, most men have a little pad of fat right above the waist on their sides. Read why one of our posters prefers this location to any other:
"I found that injecting within 4" of my belly button area caused bruising, pain, and lumps that would last for up to a week. If I inject in my love-handle area on either side of my waist, I get none of these symptoms in the slightest." 
c) Buttocks. Some men with very low body fat will find that the last place they can find enough fat to inject is in the gluts. You have to be uber careful to inject more towards your sides just to be sure you avoid the sciatic nerve. I don't see many guys injecting here, but a few have.
CAUTION: Always go with recommendations given by your healthcare provider.
I DON'T THINK SO? Delt and Quad. Some guys have injected subQ into their glut (shouder) and quad (thigh) supposedly. This is fine as long as there is really enough fat there. A lot of men probably don't have enough fat, though, and should use one of the more obvious injection sites if they truly want to be subQ.