I've taken substances of various schedules legally and otherwise before, and I've never heard of a doctor writing a prescription for methamphetamine. I really wonder if they have it in stock at my local pharmacy.
Look, this is what I'm driving at, you appear to have some illusions that methamphetamine is significantly different than other amphetamines, or has some higher toxicity profile, more addictive, IDK I'm trying to get you to tell me your biases.
At that point, we can go look at the clinical literature and see what the evidence is.