How many endocrinologists are using hgh for anti-aging?

Hopefully none: I don't know how many are using it, but there is no scientific data to support its use.

Questionable: So far, most good studies only show a benefit in people who are actually tested and shown to be hgh-deficient. Supplementing someone who has a normal hgh level doesn't seem to have a proven benefit, although some physicians might debate that point. The medication is quite expensive, and at present, is only available as an injection.