I used them in the Nineties when they were relatively easily available and hugely popular on the street, I never shot them up but knew many junkies who loved to inject them together with H or mixed them into cocktails or with Dormis. Knew a guy whose favourite combo was H, C and Rohypnol, he called it the "Triathlon", haha. These were the white 2 mg ones, later on they changed the formula (because of bad press about street use) and Roche put out the green 1 mg ones. Also remember the hysteria in the US about people using Rohypnol as a date rape drug. Apparently the colouring agent and new pressing should make it hard to inject the green ones but I knew many people who still used to shoot them up, the problem was that it became very hard to get them, doctors became extremely reluctant to prescribe them so most of the poly-drug addicts switched to the 15 Dormicums. Around the time when Rohypnol prices were going through the roof I came across this little pharmacy on one of my Thailand trips. The guy sold me Rohypnol, Dormicum, Xanax and Valium OTC in huge quantities, he even could offer me the Rohypnols in original form (blistered packing) or the generics which he sold openly in a plastic bag (he estimated generic ingredients varied between 1 and 2 mg, but the tabs were extremely fragile). I ended up buying 300 R's from this guy.
As for euphoria, enoinberlin is right, usually you don't get any euphoria from them. Just a very strong sleep aid and many people who are not used to it experience (mild) amnesia. There is some kind of reverse effect when you use them in huge quantities, I knew people who took up to 30 tabs/day and they ended up being super-hyper from the stuff. If I remember correctly according to the official conversion charts 1 mg of Flunitrazepam equals about 10 mg Diazepam or 3 mg Midazolam. But in my own experience I'd say it's much stronger, 4 mg (orally) on top of my evening shot used to put me to sleep like nothing! Usually felt groggy the whole next day.
