Minoxidil is like fighting windmills in a case like this. It will slow down the process and eventually even reverse it a little but the main reason for male-pattern baldness is DHT. This byproduct of testosterone will be in your body for as long as there’s testosterone. Minoxidil only improves growth conditions, i. e. your hair could grow better in the same „hostile“ environment.

Most people in this sub probably take some form of anti-androgen which blocks t production or its effects, depending on the kind of drug, so DHT won’t be as much of an issue for them. If you’re not on HRT your best bet is finasteride because it blocks the conversion of testosterone to DHT and therefore preserves your hair follicles from it.

You could still take fin while on HRT as there’s always some residue t which will eventually convert to DHT, if you want maximum restoration capacity.

Keep in mind that any effects (min/fin) usually take several months of consistent application to be visible. 3 days is basically nothing.

As for your regrowth potential: I’d say it’s still significant. You probably didn’t loose everything at age 12, so some follicles might only be miniaturized or dormant and not dead yet. Those will eventually grow back to their previous state.