Interesting. I've heard of doing subq but thought you didn't get as much absorption. I seems to make sense to me as muscle is active tissue with blood flow and subq just goes into the fat but, tbh, I really don't know and just speculating.
I'm on TRT so that is 1cc intramuscularly per week and I dread it. I would much rather do two .5cc twice a week with an insulin pin subq. Actually, the longest needle I've seen on an insulin syringe is a half an inch and that will go into a muscle if you are pinning the delts. I would much rather use a 29-30 gauge if the oil will go through it and I assume you have to back load it. And twice a week of cyp will give even more even levels.
What is the minimum gauge who can use to get oil to go through an insulin syringe?
Buy insulin syringes and pins separately. Use a regular drawing pin and then switch. Backloading is a bitch. I have used 30g half inch no problem. Doesn't even go in especially slowly, quick and easy. I would load a bunch at a time, say 30 pins if you want to do ED or EOD, that way you don't have to fumble around with your gear every day.
If you go on pubmed there are a bunch of studies on SC testosterone, how it's preferred for patient ease when self-administering. Even saw a study on SC test undecanoate, a 4ml shot, which caused more pain than IM but that's a huge shot, my god

There's pharmacokinetic data available.
I will do an "enhanced TRT" here now myself, I'm thinking 20mg Test E, 2.5mg Trest A and 5mg Mast P, every day or every other day if I'm lazy

Here is the Test E SC pen. A once weekly shot of .5ml.