Effect can vary a lot. I did a tolerance test with 5 mg, and even that was mind blowing. Effect was short, but my executive dysfunction was completely fixed. I cleaned, worked out, did calls and wrote letters I had been putting off for weeks. It felt like a fantastic dopamine shower.

Then, for a long time, I went with 10 - 15 mg. Slowly working up to 50 over 6 months.

The "mind blowing" effect is really fading hard one year later, though. I'm pretty sure that it's not really what the doctors want. They want regulation of dopamine and noradrenaline in the prefrontal cortex, which is a benefit that does not diminish over time. What gives the amazing feeling is excess dopamine in other regions of the brain, like a recreational drug, and that fades.