The 'dangers' are/could be that the GH isn't really GH. Long term use can affect your own output of GH meaning you might need to stay on it for life (not exactly a tragedy if you can afford kosher GH!). There's a risk of diabetes in males when using, which goes when stopping, but if you end up using it for life you've got diabetes for life!

Some research suggests an increase in cancer among GH users, an increased risk of hypertension and joint pain.

As always its risk against reward! Same goes for cost.

As for benefits, just watch the Olympias!