Because when you use it with slin you can get some huge gains. If you use slin alone you can easily just get fat. That is one reason why ppl use them together. I would like to see what other people say tho.
I'm down to 205 lbs from 249.5 lbs and I didn't run hgh. At the bodyfat I'm at right now I couldn't see hgh being better than winny to cycle. With primo and test added it seem impossible for hgh to do more.