Probably only tolerance or individual variations. It would be interesting to examine a "soft drug" analog of desoxypipradrol. I'd bet sticking a methyl on one of the phenyls could reduce the half life. Anybody got crystal data on DAT/NAT with bound inhibitors (mph, pip, amph)? Maybe there aren't any?
Started yawning some by midnight yesterday. Still stayed up til late. Sleep was similar to when after amphetamine (weird, light sleep, full of naughty thoughts and dreams, etc), but less anxiety. Felt pretty drained when getting up after 6 hours of rest. Reloaded with 13 mg's to make the day workable. Hopefully "normal" sleep will be possible late tonight, but I'm not surprised if it's not.
The half life of this sucker is the biggest obstacle keeping it from being a potential blockbuster.