Ive been on TRT for a few years now and HCG has been a part of it from the start. I have used both pregnyl and ovitrelle and I defininately prefer the ovitrelle. When you are only using 250 iu per week you are really stretching out the shelf life of a 5000 iu vial. Going off of nad size and sex drive I think that the effectiveness of the regular hcg started to drop after a couple months in the fridge. The synthetic hcg in ovitrelle still works all the way to the end. I’ve only found one source of the ovitrelle and that is Pharmacist out of the EU. IF you decide to use pregnyl for TRT I suggest getting smaller vials and only use for a month or 2.