I haven't done it yet, but am planning to shortly. 2iu is where I'm starting, if I do go up it'll never be over 4-4.5iu. Hope that helped.
There's a good thread on HGH, it's "Growth Hormone" it was started by GOON. Read it and the link Juice Authority put up. There's a lot of infromation on that thread.
JohnnyB