Methylenedioxy pyrovalerone (MDPV) is a central nervous system. Pyrovalerone and its analogs are inhibitors of the transporters for certain monoamine neurotransmitters, including dopamine and norepinephrine, preventing their uptake.1,2 3,4-Methylenedioxy Pyrovalerone (3,4-MDPV) is an analog of pyrovalerone which includes the 3,4-methylenedioxy moiety found on 3,4-methylenedioxymethamphetamine, a DEA Schedule I controlled substance. While its physiological, neurological, and toxicological actions have not been characterized, 3,4-MDPV has been reported by the DEA to be abused as a central nervous system stimulant.3 Its effective dose and chemical interactions are unknown, but it has been used alone and in combination with other stimulating compounds. Products containing 3,4-MDPV have been marketed in Europe and Australia; they have also been seized by law enforcement in several states.3 3,4-MDPV and some of its metabolites have recently been characterized by spectroscopic analysis.4,5,6,7 3,4-MDPV is to be used in the forensic analysis of samples that may contain this compound. This product, the hydrochloride salt of 3,4-MDPV, has superior solubility in aqueous solvents, compared to the free base.