Drug info - an undetectable drug?

[Marc]

Hi, i looked around and cant find much on this. There is a new drug going around my area that is supposedly undetectable in drug tests (you come up clean). The street name is sunshine. Not orange sunshine or yellow sunshine. I cannot remember the actual scientific name of it but i know it starts with an M. I heard that when a drug dog confronts this drug it will discard sunshine as nothing. In the lab, it is classified as nothing as well. Now i am new and the information i received was from a friend of a friend who knows people that have got away with using this drug. People ingest sunshine with a liquid or snort it. My questions are,
what is sunshine?
Is it illegal?
Are the accounts above plausible?