Trifluoromethylphenylpiperazine

3-Trifluoromethylphenylpiperazine (TFMPP) is a recreational drug of the piperazine chemical class. Usually in combination with its analogue benzylpiperazine (BZP), it is sold as a alternative to the illicit drug MDMA ("Ecstasy") under the name "Legal X".

Pharmacology

TFMPP has affinity for the 5-HT_1A (K_i = 288 nM), 5-HT_1B (K_i = 132 nM), 5-HT_1D (K_i = 282 nM), 5-HT_2A (K_i = 269 nM), and 5-HT_2C (K_i = 62 nM) receptors, and functions as a full agonist at all sites except the 5-HT_2A receptor, where it acts as a weak partial agonist or antagonist. Unlike the related piperazine compound meta-chlorophenylpiperazine (mCPP), TFMPP has insignificant affinity for the 5-HT₃ receptor (IC₅₀ = 2,373 nM). TFMPP also binds to the SERT (EC₅₀ = 121 nM) and evokes the release of serotonin. It has no effects on dopamine or norepinephrine reuptake or efflux.

Use and effects

TFMPP is rarely used by itself. In fact, TFMPP reduces locomotor activity and produces aversive effects in animals rather than self-administration, which may explain the decision of the DEA not to permanently make TFMPP a controlled substance. More commonly, TFMPP is co-administered with BZP, which acts as a norepinephrine and dopamine releasing agent. Due to the serotonin agonist effects and increase in serotonin, norepinephrine, and dopamine levels produced by the BZP/TFMPP combination, this mixture of drugs produces effects which crudely mimic those of MDMA.