Trifluoromethylphenylpiperazine

3-Trifluoromethylphenylpiperazine (or simply TFMPP) is a piperazine-based drug. It has no medical uses, but has been sold as a recreational drug used as a "legal alternative" to illicit drugs such as LSD and MDMA.

Pharmacology and Effects
TFMPP acts as a non-selective agonist at 5-HT1B, 5-HT2A and 5-HT2C serotonin receptors. TFMPP is rarely administered by itself, and there has been little research into it as a single drug. More commonly, TFMPP is co-administered with another piperazine derivative BZP, which increases synaptic levels of serotonin and dopamine via action at the VMAT-2 vesicular monoamine transporter, in addition to being a serotonin agonist in its own right.

Due to the serotonin agonist effects and increase in dopamine levels produced by the BZP/TFMPP combination, this mixture of drugs produces effects which crudely mimic the effects of MDMA ("ecstasy") in animals, and so have been advertised as an "MDMA substitute" to consumers. The subjective effects of this combination are often portrayed as being similar to those of MDMA, but actually are quite different, lacking any empathogenic effects.

In fact the effects of TFMPP are more similar to hallucinogens such as LSD or (more similarly) mescaline, although much weaker, with the maximal 5-HT2A agonist effect of TFMPP found to be only 40% compared to the strong hallucinogen DOM. So it would be more accurate to describe the combination of BZP and TFMPP as being closer to a combination of a weak dose of LSD mixed with amphetamine rather than comparing it to MDMA.

However research has shown that in addition to the effects on serotonin, the combination results in an unexpectedly large amount of dopamine release that far exceeds what one would expect from the DA releasing properties of each drug alone added together. This suggests a strong degree of synergy between the two drugs. 

TFMPP has only mild effects when not combined with benzylpiperazine, and it produces aversive effects in animals rather than self-administration, which explains the decision not to permanently make TFMPP an illicit drug.

TFMPP has also been previously reported as a metabolite of the analgesic antrafenine. TFMPP shares some features with fenfluramine.

The dosage commonly used when combined with BZP for "ecstasy-like effects" is between 30 and 100 mg, while higher doses of TFMPP alone cause mildly hallucinogenic effects at around 100–250mg; however, higher doses can cause a range of side effects including migraine headaches, muscle aches, nausea and vomiting, as well as a come-down syndrome characterised by insomnia, loss of appetite, and headache; these side effects tend to discourage abuse of TFMPP.

Legal Status
As of December 3rd 2005, TFMPP is illegal in Denmark. As of March 1 2006, TFMPP is scheduled as a "dangerous substance" in Sweden. TFMPP was briefly emergency scheduled in Schedule I in the USA, but the scheduling expired in April 2004 and has not been renewed. Therefore, unlike its cousin benzylpiperazine, TFMPP is not currently an illicit drug in the USA.

Side Effects
The combination of BZP and TFMPP has been associated with a range of side effects, including insomnia, anxiety, nausea and vomiting, headaches and muscle aches which may resemble migraine, seizures, impotence, and rarely psychosis, as well as a prolonged and unpleasant hangover effect similar to that produced by alcohol. These side effects tend to be significantly worsened when the BZP/TFMPP mix is consumed alongside alcohol, especially the headache, nausea and hangover.

However it is difficult to say how many of these side effects are produced by TFMPP itself, as it has rarely been marketed without BZP also being present, and all of the side effects mentioned are also produced by BZP (which has been sold as a single drug). Studies into other related piperazine drugs such as mCPP suggest that certain side effects such as anxiety, headache and nausea are common to all drugs of this class, and pills containing TFMPP are reported by users to produce comparatively more severe hangover effects than those containing only BZP.