HCG is produced by pregent women it's what pregency test kits test for. Men don't produce it instead we think it's LH and it behaves like LH which is a testosterone making hormone.
On a cycle you'll have supression your testicles can shrink because they have gone on holiday, somewhere like Florida or the moon if it's Tren. You can use HCG to say "I know you're on holiday but you need to start working" and they'll goto work. That's the idea.
Theres alot of split opinions on HCG and roids. Some people say use HCG all the time and you never shut down. What you could do is near the end last 2-3 weeks of a cycle start HCG so they start working ready for PCT. The HCG is supposed to be temporary so it'll drop off but by then you can start nolva.
A dose is like 250ui-500ui twice a week. I used HCG for my crashed fertility after a SARM cycle. It's suppose to be god for that.
You mix the bac water with the vial, vials are normally 5000ui and it's injected into the stomach fat. Sub q.
Hope this helps.