The delt is a small muscle so any injection that hurts really should go to the glutes. with an every other day injection he really should rotate sites better than just right delt one day and left the next. When I am using something that hurts, like test, I go left glute one day, then on the next injection I go right glute, then the next one I inject half into the right Vastus Lateralis (outside of the thigh) and half into the left Vastus Lateralis. If you inject all of it into one VL then you will walk with a mad limp for a couple days post injection. Anything that is foreign to the body will be attacked by the body's defences. Last time I heard, you don't have alot of sesame oil or BA/BB floating around in your body naturally. The knot that forms is from that interaction. It will go away in about 5-7 days. That is why you wanna rotate as much as possible and go in the larger muscles. Btw, the freaking 25 guage pin is too fucking small. He needs like a 22 because test is thick as glue.
