Ironically, testosterone in theory is harder to get. Since it is widely used for sports doping, it's considered an anabolic steroid, and is a scheduled substance in the US, and so has a bit more oversight to prescribe and dispense. (But I imagine there's probably also a larger black market for it for the same reasons.)

There are a billion TRT clinics that will prescribe you testosterone with basically zero oversight and at dosages that are supraphysiological.

And yes, the black market is huge - anyone with google and the ability to purchase crypto can get it easily delivered, either domestically, or from china.

Not only TRT but also Tren and other anabolic steroids that work in tandem with Testosterone to boost lean mass and reduce fat.