But is it illegal for Joe Blogs to take them?
Not illegal to take them AFAIK ( although not that bright either ), might be illegal to have them ( see above ), can't immediately think of a way to supply them without a prescription that wouldn't be illegal and prescribing them for sports related purposes as opposed to a medical treatment for a specific condition may still be illegal and certainly wouldn't play well with the GMC.
Not sure that most of the medical hormone replacements would benefit one anyway. Oral contraceptive pill won't help you confuse the gender testing; thyroid hormone will make you stay up nights, sweat, eat like a pig, have a fluctuating weight and make your heart race; most classes of steroids unhelpful/harmful. Some people have used insulin as an anabolic agent but its relatively easy to tell the artificial from the real and the potential side effects are offputting ( and much more likely in the non-diabetic ). EPO etc. well documented and well detectable ( and I find the use of what is a relatively scarce medication for cheating in sport, at the cost of it being available for those who need it, shameful ). Growth Hormone has anabolic effects in theory, but we still haven't worked out whether replacement actually helps those adults who are deficient, never mind what effects it has on those who already have sufficient.
Thanks, rant over, but useful in keeping the work related bit of my brain ticking over whilst I am stuck at home with a chest infection.