If my dad is prescribed testogel would it be illegal for him to give me some? Like would social services be called or something? He’s gonna try and get a prescription for himself to use a little but mainly for me because the NHS suck, I’ve been socially transitioned for 5 years now but because I’m (barely) under 16 they won’t prescribe ofc. I know the right dosages and I think I’ll be able to order blood tests from the GP but I’m worried my parents could be reported if it was figured out :/
There are multiple reasons this could be a bad idea, and yes, there is a chance your parents could be reported (to e.g. the police).
Legal: all forms of testosterone count as anabolic steroids, which are a Class C drug, and it is illegal to supply these to other people (whether or not the drug was originally obtained with a prescription). The law says that supplying it to someone can be punishable by up to 14 years in prison/an unlimited fine. More generally, it’s illegal to give your prescription medication to other people - though it’s not that common to end up in legal trouble for this, the complicating factor of testosterone being a Class C drug could make doing it much more dangerous.
Medical: without baseline blood tests and knowledge of whether there are any medical issues that could be exacerbated by testosterone (e.g. liver issues), taking testosterone could be dangerous. You say you think you could get your GP to do blood tests, but your results would end up being “unusual” if they don’t know you’re on testosterone, and there’s a significant chance they could put two and two together and work out your dad is supplying you (especially if they are also monitoring him), which feeds into the legal issue above. Not having monitoring blood tests would also be far from ideal, because you need to know how your testosterone levels are doing and whether there are any problems. Though it’s rare, it sometimes happens that people taking testosterone without adequate supervision can have potentially serious medical issues which mean they have to stop taking testosterone altogether, or at least for some time - something which can be physically and emotionally difficult to cope with.
In short, I would strongly recommend against trying to do this. In theory, it is possible to get testosterone prescribed on the NHS from the age of 16, but it depends on where you are in terms of seeing a gender clinic. You don’t say anything about whether you’re on a GIC waiting list or whether you’re being seen by one so I can’t say too much about this, but it’s perhaps worth speaking to your GP about your options. I would also suggest getting in touch with Gendered Intelligence and Mermaids, which are both organisations supporting young trans people and their families.