I have a friend who went to school in London, I'm from the US......
As a general rule, when they were legal until 15 months ago, MDPV was being sold as "bathsalts" and mephedrone was being sold as "planfood".......It was literally in normal "gas-stations" right next to the condoms.....
I opted for the "bathsalts" the 4 times I used anything like that, but I wish I had tried the "plantfood", because Mephedrone, by all accounts sounds a lot more mellow than MDPV, which if I had to put money on it, I think is what I had....lost my mind my completely on whatever it was, worse than any drug Ive ever used!
Just a story...
Oh wait, yeah...my friend who went to school in London did mephedrone a number of times and the way he described it sounded a lot more fun tha what I experienced from "bath-salts"....
thats it....