That's water retention for sure. I found it worse the first time I used it or if I am consuming too much sodium or drinking even moderate amounts of alcohol. It subsided for me after a few weeks, especially after I reduced my sodium intake and stopped all alcohol. You could try a nautical diuretic like dandelion root. I hear it works for some for this issue. Caffeine is also a useful diuretic as it high dose vitamin c and of course upping your water intake.

It makes you retain extra water weight. HGH is definitely not going to put fat on you that's for sure. Overtime it will obviously add muscle but that only happens at certain doses and over a long period of time.