Now that the DEA has banned fake pot (or at least banned five of the myriad chemicals that can be used to make it), fake speed is next in line as the scary legal high du jour. A recent A.P. story blames methylenedioxypyrovalerone (MDPV)—the active ingredient in "bath salts" that are sold under brand names such as Cloud 9 and are supposed to simulate the effects of methamphetamine and cocaine—for hallucinations, paranoid delusions, domestic violence, and suicide as well as "rapid heart beat" and "hypertension." The article also mentions another stimulant, mephedrone, a.k.a. 4-methylmethcathinone, which reportedly has empathogenic effects similar to MDMA's. Mark Ryan, head of the Louisiana Poison Center, tells A.P. "users describe the drugs as many times more potent than Ritalin or cocaine." Henry A. Spiller, director of the Kentucky Regional Poison Center in Louisville, says even "experienced drug users" can't handle these drugs' "fairly nasty effects."
These third-hand reports should be taken with a grain of (bath?) salt. MDPV and 4-methylmethcathinone both get mixed reviews at Erowid, but the general impression is not that they are substantially more dangerous than the illicit intoxicants for which they are supposed to serve as substitutes. Still, they are not nearly as well researched, and their long-term effects are unknown, so these "bath salts" (also sometimes sold as fertilizer or insect repellent, according to A.P.) are yet another example of how prohibition makes drug use riskier.