In fact, choice of location for the injection is not so important though you should remember certain things. Muscles of the buttocks and thighs are best suited for large volume injections especially for athletes taking steroids for the first time. In such places, injection volume of 3 ml will not lead to more irritation.
Injections in the shoulder or other small muscles should not exceed 1-1.5 ml, or more of drugs can lead to pain and swelling of the muscles. Muscles of the buttocks are best suited to start taking steroids, as the least painful injections in these places. Circulation in these muscles affect the absorption of the hormone, although the injection is almost irrelevant in this case.
Administration of the hormone is present in these muscles for long enough, the hormones are absorbed faster in the muscles of the thigh or upper arm (the fastest). Throughout the cycle, the injection does not play a big role for the athletes.