Little is known about 3,4-methylene-dioxy-pyrovalerone (MDPV), a new designer drug that has become popular in Hungary in the last couple of months. At the same time, its consumption, as a consequence of its low street-price, rises so fast that the event can be considered an epidemic. This paper reviews the chemistry, biochemistry and metabolism of MDPV. Then, on the basis of a few international reports and the author's own clinical observations, it discusses MDPV intoxication and withdrawal. In the metabolism of MDPV, the most important catalyst is the CYP2C19 isoenzyme, but the CYP1A2 and the CYP2D6 isoenzymes also play a crucial role. The formed catechols are conjugated with either glucuronic acid or sulfate. It is important to note that MDPV is consumed either together or in a sequence with other illicit drugs of abuse. As far as it can be established, MDPV use increases the activity and vigilance, decreases appetite and claim to sleep, but it can also provoke cardiac sensations and disturbance of perception. In the course of coming down, withdrawal after MDPV use, bone and muscle pain, hypersomnia, disturbance of vision are experienced, but panic attack may also occur. The appearance of new designer drugs on the market draws attention to a need of paradigm changing in spiritual field. Unless it happens these negative trends likely will speed up.