I'm Rx'd Desoxyn (d,-meth), so that kind of makes me have no interest in street meth. I mean, if a friend randomly pulled out a nice, shiny, pure-looking meth crystal I'd probably give it a go, but I find stimulants don't cause the same effects in me as they do in everyone else. Plus, I wouldn't know where to start dosage-wise: it'd obviously be higher than someone with no tolerance because I have taken it medicinally every day for almost a year (note: teeth are fine, skin is fine; in fact, I get compliments on how good of teeth/skin I have) and I certainly wouldn't want to over-do a drug of this calibre.
Plus, I just don't really know how much I'd enjoy it... My Desoxyn (along with all other stimulants EXCEPT d,-amp) has a calming effect at "my therapeutic doses" (20mg d,-meth/day, 40mg d,-amp/day, 60-90mg d,l,-amp/day, 70-90mg m,phenidate/day, etc). D,-amp, aka Dexedrine or Dextrostat, is the only upper that gives me euphoria, but the effect requires continual dosage increases and before I knew it I was taking 90-150mg of Dexedrine/night to feel the same as 10-15mg had made me feel 2 months prior. That's why I don't abuse my Rx meds anymore; I know that nothing good comes from it.
I also figure that my 20mg of pure dextro-methamphetamine would be equal then to about 40mg of racemic methamphetamine (the l,-isomer has almost no effect, even less so than l,-amp vs. d,-amp). Street meth can be anywhere from 10-90% purity, but I bet the average (by the time it gets to the end user and has been stomped on by however-many people; no to mention most "chemists" aren't exactly the most skilled drug manufacturers) purity is 30-50%. So, technically, over the course of the day I am consuming anywhere from a bit less to a bit more than a point of street meth orally.
When I first started taking it, it DID have a STRONG difference in effects, and my first month was only at 10mg/day switched from 40mg/day Dexedrine. I could definitely tell it was much more serotonergic, and didn't screw with my norepinepherine as my heart rate didn't go up and my BP dropped. I was actually afraid to take the pills the first time; I've never been afraid to take an Rx drug before. I just knew that they were the "end of the line" ADD medicine, so they must be pretty damn potent.
Anyway, being so ADD and having been Rx'd meth for a year, I don't know that I'd even get the "typical" effects from it. Most likely, it would do what cocaine and amps do, and that is cause me to sit and think calmly and quietly. They slow me down as opposed to speed me up, but I don't know what "large" doses of street meth taken intranasally/smoked/IV'd would do. I'm not trying to thread-jack, just adding my own experience. Anyone in a similar situation have any experience?