Also whats the youngest age you can get it? How do you get it?
Depends somewhat on the country you live in but the normal age for starting Testosterone is 18 at the earliest. As for how to obtain it, though a doctor. It's a prescription drug and you require regular blood test to verify you are receiving the correct dosage and that you liver is able to handle it. If you live in a country like England, going through the national health service can take a long time so you are best starting as soon as possible. In the United States, the delay can be far shorter.
Depending on the country you come from there might be the possibility to go private or look for an endo/doctor willing to start at a younger age.
https://www.susans.org/forums/index.php/topic,208503.msg1848162.html#msg1848162
You might ask at lgbt orgnizations, plannedparenthood or look via the internet if you are from the us.
You also might look for an experienced gender therapist willing to help.
They also may be able to write letters for hrt for doctors/endos.
Here are online therapists who also may be able to write letters:
https://www.susans.org/forums/index.php/topic,187135.0.html
hugs
In the US, with parent permission, you could probably get a doctor to prescribe it at 16. But expect to jump through some hoops. You'd most likely be looking at 18.
You would either need to: (1) go to therapy, get a referral from your therapist for HRT, find an HRT provider, get a prescription from them; or (2) find an HRT provider that operates on the informed consent model, and get a prescription from them.
The second way is obviously faster, but if you're planning to have insurance pay for anything later on in your transition, you'll want to make sure that you're following their requirements. Some want you to do therapy, then T, etc. before they'll cover any kind of surgeries.
I started testosterone at 16 with my mother's permission. I got a note from my therapist and a referral to a new doctor who could monitor and prescribe me hormones. not sure about different countries, but I live in the US