These "salts" are MDMA, or an analog of the chemicals that comprises MDMA. These do act as a vasoconstrictor, which can induce a "rush" or speeding sensation. Even small doses over a long period of use, will cause a period of nervousness and to some extent paranoia. Has been known to cause sweating, loss of appetite, slower thinking w/ short term memory loss. It's effects seem to slowly terminate with decreasing use. MDMA has also been seen as a legal alternative for addicts who abuse crystal meth and are in substance withdrawal. Xanax is the standard advisable prolific for MDMA over-use and over-dosing. No clinical work performed on the over use of these "salts", only personal experience of users, not in trial, as of this date 4-11.