Most doctors are clueless and so expect inaccurate information from your doctor as most have no education in this area of medicine because there is no specialists in this area of medicine within the medical community. I inject in the shoulders and quads using 29 gauge insulin syringes and companies have patented sub-Q auto-injectors and wouldn’t do so if it didn’t work.
Basically your doctor sees the prescription label which states “intramuscular injection only” not having tried it himself and assumes nothing else will work. TRT requires someone who challenges the mainstream, thinks outside the box to break away from the rest of the sheep.
You will cause muscle tissue damage over time using the large, long 1"-1.5" syringes.