Needle length question and DHT

Hi guys, 24 year old male on TRT. My doctor gives me preloaded syringes with a 1 inch needle. I am use and most comfortable doing glute injections however i have around 15-20% bf and was wondering if this may be to short. Also my hair has been falling out quite fast and was wondering if for some reason it may not be getting fully into the muscle a higher rate of DHT can arise from this. Thanks guys

Needle length question and DHT