Ansomone for me atm but heard plenty of good reliable feedback about GenX and will definitely like to try it myself at some point.
Good starting point depends on personal goals....and budget!
General health, fat loss, well-being, etc maybe somewhere between 2-3iu daily?
For bodybuilding anything above this, depends on how much you can afford and how you get on with the management of any side effects such as CTS, joint pain, numb fingers, swollen hands, etc.
One thing worth mentioning is that HGH is a slow burner and it takes time to see the results. The same goes for sides, they can take a while to manifest so my advice would be to make any upwards dose adjustments slow and incremental, eg don't just jump say from 3 iu to 6 in one go, do it progressively over a number of weeks because by the time the sides manifest you could be in some real discomfort lasting for several days or even weeks, even after discontinuing.
Weirdly, I like, even crave the mild side effect of growth, the numbness in the fingertips makes me know it's doing its thing, but overdo dose too quickly and shit the bed! it can be really unpleasant.
One of the worst ones for me personally is the locking out of knuckle joints when I clench a fist, the middle finger locks tightly closed and only way to unlock it is to quickly snap it back open with the other hand....fucking hate that shit!!!
