Guys where do you live, Congo?
Any lab that can test somatomedin (IGF-1) can also test for somatotropin (HGH). Just hand your wallet...
Here in Italy it costs around 35 euro to check for somatotropin and I live in Sicily, surely not the most advanced county in Italy, lol.
Regarding the timing, just do what I have been doing in the last 10 years so get into the lab 30' after your injection, which must be IM.
In this way, if what pinned was HGH, the result will be beyond the highest level of the lab ranges.
By the way, I am on HRT since 7 years already and started using steroids when I was 19yo. I accomplished 37 cycles and 3 PCT...Currently, I am on HGH from Hygene at 10 iu ed since 7 months.