I've been using pharma GH for a while. You can get a baseline serum GH and IGF-1. Blast GH and pull bloods within 30 minutes to test GH serum levels. You can also get IGF-1 serum levels tested anytime within the weeks / months after using GH. GH tripled my IGF-1 levels in the first week.
There are a lot of opinions on how to use GH. Mine is that it should be used intermittently - 2 weeks on 6 off is a good guide. It will keep your IGF-1 levels high. Don't use too much GH for too long or you'll get massive water retention in the short term and probably distended gut in the medium / long term. It's a waste of money to use GH daily, continuously as intermittent use is enough to raise IGF-1 levels and keep them raised. It's the best way to avoid medium / long term sides too.