Hypothetically speaking, it's possible to for transition without a doctor's direct supervision. This section describes how certain hormones might be obtained and injected.
Testosterone
Illegal to acquire. This website does not endorse any attempt to obtain non-prescription testosterone, as it is a controlled substance.
Importing testosterone is a crime, so those who do order it often have to just wait for it to show up. If the package is lost or intercepted, let it go- it's gone. Pursuing it could put the purchaser in trouble. For this reason, many people who DIY buy one vial at a time, so that if one gets lost, it's not a total loss and there's still a chance of receiving others. It's also much less suspicious.
50mg/week is the typical trans man starting dose. Going beyond 100mg/week is not generally recommended unless testosterone levels are still insufficiently low. Testosterone vials often have concentrations between 200mg/mL, 250mg/mL, or 300mg/mL. In a 300mg/mL vial, 1mL of liquid has 300mg testosterone. A 10mL vial would hold 3000mg.
The formula to calculate how much liquid to inject is: (desired injection dose)/(vial concentration) = amount to inject (mL)
Injecting 100mg with a 200mg/mL vial- 100/200 = 0.5mL per injection
Injecting 50mg with a 250mg/mL vial, 50/250 = 0.2mL per injection
Injecting 50mg with a 300mg/mL vial, 50/300 = ~0.17mL per injection
If a man wanted to calculate the number of weeks a bottle would last, there's a little more math involved. Say there is a 250mg/mL vial that holds 10mL testosterone. The man is doing doing 50mg injections. Each injection is 0.2mL. Divide 10mL by 0.2mL to get the amount of doses the man will get from this bottle. This ends up being 10/0.2 = 50 doses. Doing weekly injections, he should get 50 weeks out of this one bottle.
However, it must be assumed that he will lose extra testosterone with each injection due to "dead space-" liquid left in the syringe after injection that the body won't receive. The best practice here is to assume 0.1mL will be lost each time he injects.
Going back to the previous example of an ideal 50 doses where he injects 0.2mL, now assume he draws up 0.3mL to combat the loss of 0.1mL to dead space. 10/0.3 = about 33 doses. This would last him about 33 weeks. That's a big difference compared to the original 50 doses/weeks calculated earlier.
Obtaining T
Those who purchase hormones online often do so through the use of a TOR browser to preserve their privacy. They might search internet forums that gym bros use to discuss buying their steroids.
Injection supplies can be bought online or in-person at pharmacies. When buying syringes to use for injection, 1ml syringes are most highly recommended. The small doses used when injecting are difficult to measure otherwise. 3mL syringes can also work if 1mL syringes are not available, though.
The process for buying DIY T seems to follow along these lines:
1. Choose a website that ships to your location using the list in the DIY HRT guide
2. Choose a bottle of T that suits your needs
3. Check the reviews- is it reliable/well-rated?
4. Do the math to determine how many doses it would provide.
5. Place the order, paying via whatever method the site requests.
6. Wait for it to arrive. Some people purchase injection supplies at this time.