25ga gets hard to push more then 1cc of oil thru. ALso forget about using Stanoz in a 25ga.
Also, a 1 1/2" 25ga is harder to push oil thru than a 1" 25ga.
For a 1cc delt shot I can use 25ga. 1".
Glutes? 1" or 1 1/2" 23ga for me.
The more cc of oil your injecting and the longer the needle, the more you need bigger diamater.
I cant see needing larger than 1 1/2" 23ga.
YOUR personal size of the muscle being injected, and your body Fat determines length of the proper needle.
Im sure the hospitals have stuff like 3" 22ga needles for these fat muthas these days.