I'm a physician who's prescribed medications for many ADHD adults. Methamphetamine (MA) is legal to prescribe for ADHD and indeed a few patients had best result

I'm a physician who's prescribed medications for many ADHD adults. Methamphetamine (MA) is legal to prescribe for ADHD and indeed a few patients had best results with it. MA isn't "stronger" than D-amphetamine but may be better tolerated. AIUI the main reason MA is the dominant street amphetamine-type drug is that it's easier to synthesize in clandestine labs vs. classic amphetamine. At equivalent doses the effects are similar. In any case you're right that there's a big difference in street drug use vs. therapeutic doses. For street drug user a typical daily dose is on the order of 1000mg whereas prescribed doses are with few exceptions 1-2 orders of magnitude below that. MA in particular is in the lower end of the range, I'd say 10-20mg/day (partly due to it being a very expensive pharmaceutical product if in fact it's even being manufactured at present).