Also known as

BZP, party pills, PEP, legal x, nemesis, TFMPP, A2, frenzy, euphoria, the good stuff, smileys, silver bullet, rapture, pep twisted, pep stoned, pep love, legal e, happy pills, fast lane, exodus, cosmic kelly, bolts extra strength, blast, benzylpiperazine




Piperazines are a group of chemicals that include BZP, TFMPP and mCPP. These were part of the popular 'party pills' market that emerged around 2006 [1].

Piperazines are a very broad chemical group, covering a wide range of drugs from antidepressants to antihistamines. The connecting property of all these chemicals is the presence of a piperazine functional group. Piperazine is a fairly basic compound. Recreational use of certain piperazines is due to the much desired effects that are experienced with MDMA. This section on piperazines will refer solely to these recreationally used derivatives, focusing predominantly on BZP, TFMPP and mCPP [1].

Piperazines are a broad class of chemical compounds which mimic the effects of ecstasy. They were produced as a legal alternative to ecstasy (though have since been classified as Class C drugs) and have been found as a cutting agent in some ecstasy pills. The best known piperazines are BZP (benzylpiperazine), TFMPP, DBZP and mCPP [2].

Medical usage

Thought to have been originally developed in the 1950's as an anti-parasitic drug for use in farm animals, but was abandoned as a worm treatment due to side-effects. There are no current medical uses [3].

What does it look like?

BZP and TFMPP- white pills (occasionally various colours) [1].

Piperazines can come in various forms and shapes. Pills can be red, blue, pink, white, off-white, purple, orange, tan, and mottled orange-brown. They can carry an impression such as a housefly, crown, heart, butterfly, smiley face, bull's head, autobot, bird flying, Mickey Mouse, five pointed star, Superman and a witches hat.

Piperazines are also sold as an off-white powder, in capsules and as a liquid [2].


Piperazines are used in the manufacture of plastics, resins, pesticides, brake fluid and other industrial materials [3].


Prevalence data on BZP and other piperazines is limited. Before piperazines were brought under the Misuse of Drugs Act in December 2009, most sales were conducted on the internet. The number of UK websites that sold the drug or websites based abroad that shipped to the UK suggested that there was a fairly significant number of users in this country.

An online survey conducted in late 2009 in collaboration with the magazine Mixmag showed that amongst this particular user group of clubbers 25.8% had ever tried BZP and 12.1% had tried it within last year (Winstock, 2010). In 2011, the same survey showed a drop with 17.2% having ever tried BZP and 5.0% having tried it within the last year [4].

Street price

The pills can cost between £5 to £10 [2].

Why take it?

Sought after effects

BZP - similar to amphetamines

  • wakefulness,
  • euphoria [1].


  • mildly hallucinogenic - i.e. changes the way your brain sees things (when used alone at higher doses),
  • in combination with BZP, similar to MDMA (ecstasy) [1].

Undesired effects


  • mild headaches,
  • fatigue,
  • insomnia,
  • nausea [1],
  • vomiting,
  • stomach pain,
  • dry mouth,
  • agitation,
  • anxiety,
  • irregular heartbeat,
  • diarrhoea,
  • allergic reactions,
  • fever,
  • fits [3].


  • migraines,
  • muscle pain,
  • nausea,
  • insomnia [1].



  • light - 40 - 70 mg,
  • common - 70 - 100 mg,
  • strong - 100 - 130 mg,
  • heavy - 130 mg + [5].

What are the different forms?

  • BZP, full name benzylpiperazine, is most commonly found in ecstasy tablets but can also be found pure in both tablet and powder form. BZP was studied as a potential anti-depressant, but was found to have euphoric qualities similar to amphetamine so studies were stopped.
  • TFMPP, full name 1-(3-trifluoromethylphenyl)piperazine, is rarely taken on its own, but is more commonly mixed with such substances as BZP and pressed into pill form. The mixture is made to try and mimic the effects of MDMA, where TFMPP is meant to reproduce the psychedelic effects of MDMA, and BZP the euphoric effects. The BZP/TFMPP mixture can be found on its own or in ecstasy pills.
  • mCPP's full name is m-chlorophenylpiperazine was a research chemical initially synthesised in the late 1970's as a potential anti-depressant. The drug has never been licenced for medical use, but is known to metabolite some anti-depressants. Recreational use was first reported across Europe and many other countries in the mid-2000's due to an eruption of the substance being sold as a 'designer drug' that mimicked the effects of MDMA. mCPP is another stimulant that is also found regularly in ecstasy pills [1].

How long do its effects last?

Onset of effects

  • all ROA's - 30 - 45 minutes [5].

Duration of effects



The piperazines are a large group of chemicals. The focus here will be on the recreationally used derivatives, that is the benzylpiperazines (i.e. BZP) and the methylenedioxy derivatives (e.g. TFMPP, mCPP, MeOPP), the latter being most similar to MDMA as its name suggests.

There is very little pharmacological research on this group currently, and most of the studies that do exist look predominantly at bzp, tfmpp, mcpp as these are the most commonly used substances.

BZP - acts to increase serotonin in the central nervous system and prefers serotonin 5-ht type 1 receptors. This gives the user the amphetamine-like effects that are commonly noted when taking BZP.

TFMPP - also interacts with the serotonergic system through 5-ht type 1 and type 2 receptors. It is considered 3 times less potent than MDMA at increasing serotonin by inhibiting its reuptake.

BZP + TFMPP - these two substances seem to work synergistically in the central nervous system. Even at low doses, they increase levels of serotonin and dopamine parallel to each other mimicking the effects seen in MDMA. Some studies have even shown that at higher doses of both drugs, a greater level of dopamine is produced than the drug on its own.

Mcpp - interacts with a wider array of receptors and transmitters, mainly serotonin, adrenaline and dopamine. This is why the euphoric and hallucinogenic effects are seen to be similar to MDMA. Mcpp may also cause serotonin syndrome. This is a very high level of serotonin build up which causes the user to experience fever-like symptoms and can sometimes be fatal [1].

How is it taken?

Swallowed [1].

BZP is typically obtained in the form of a powder, tablet or capsule, so will usually be swallowed. However, the powder may be snorted or smoked. Intravenous use is also a possibility but is rare. Oral consumption of the free-Base liquid is not advisable due to its corrosive nature and will burn [3].


Minor effects

Less common

  • abdominal or stomach cramps or pain,
  • diarrhoea,
  • dizziness,
  • drowsiness,
  • headache,
  • muscle weakness,
  • nausea,
  • tremors,
  • vomiting [6].

Major effects

If any of the following side-effects occur while taking piperazine, contact your doctor immediately -


  • blurring of vision,
  • clumsiness,
  • crawling or tingling feeling of the skin,
  • fever,
  • irregular, twisting movement, especially of the face, arms, and legs,
  • joint pain,
  • skin rash or itching [6].




Long term risks are not yet fully known but may include respiratory failure, Serotonin toxicity and other medical complications as a result of toxicity. BZP has the potential for psychological dependency and mental health problems [3].


The chemical composition of substances sold as piperazines are changing all the time which is why you can never be sure what you're getting and how it could effect you [2].


Can you get addicted

Early studies suggest that you can become dependent. It is very similar to amphetamine use, i.e. taking speed [2].



  • αMT,
  • Tramadol - Tramadol and stimulants both increase the risk of seizures.
  • MAOIs - MAO-B inhibitors can increase the potency and duration of phenethylamines unpredictably. MAO-A inhibitors with amphetamine can lead to hypertensive crises [5].


  • DOx - The combined stimulating effects of the two can lead to an uncomfortable body-load, while the focusing effects of amphetamine can easily lead to thought loops. Coming down from amphetamines while the DOx is still active can be quite anxiogenic.
  • NBOMes - Amphetamines and NBOMes both provide considerable stimulation. When combined they can result in tachycardia, hypertension, vasoconstriction and in extreme cases heart failure. The anxiogenic and focusing effects of stimulants are also not good in combination with psychedelics as they can lead to unpleasant thought loops. NBOMes are known to cause seizures and stimulants can increase this risk.
  • 2C-T-x - Stimulants increase anxiety levels and the risk of thought loops which can lead to negative experiences. In extreme cases, they can result in severe vasoconstriction, tachycardia, hypertension, and in extreme cases heart failure.
  • 5-MeO-xxT - The anxiogenic and focusing effects of stimulants increase the chance of unpleasant thought loops. The combination is generally unnecessary because of the stimulating effects of psychedelics.
  • DXM - Both substances raise heart rate, in extreme cases, panic attacks caused by these drugs have led to more serious heart issues.
  • PCP - This combination can easily lead to hypermanic states [5].


Piperazines are Class C drugs which means that they're illegal to have for yourself, give away or sell.

Possession can get you up to two years in prison and/or an unlimited fine.

Supplying someone else, even your friends, can get you 14 years in jail and/or an unlimited fine [2].

What if you're caught?

If the Police catch you with piperazines, they'll always take some action. This could include a formal caution, arrest and prosecution [2].

  • A conviction for a drug-related offence could have a serious impact. It can stop you visiting certain countries - for example the United States - and limit the types of jobs you can apply for [2].

Did you know?

  • Like drinking and driving, driving while impaired by piperazines is illegal - you can get a heavy fine, be disqualified from driving or even go to prison.
  • Allowing other people to supply drugs in your house or any other premises is illegal. If the police catch people supplying illegal drugs in a club they can potentially prosecute the landlord, club owner or any person concerned in the management of the premises [2].

Mixing with other drugs

Mixing piperazines with alcohol can be particularly dangerous - the effects of these two substances interact, and you may also be less in control, making use much riskier [2].

Harm reduction

  • Piperazines, as with all synthetic stimulants, are best avoided if you have high blood pressure or heart disease, epilepsy or liver problems.
  • If taken in hot clubs or while engaged in activity such as dancing be sure not to overheat. Take time out somewhere cool and sip water slowly (One pint /hour).
  • Start low and go slow. Take a quarter to a half of a pill and wait a couple of hours to gauge the effects.
  • Do not take these drugs with alcohol, other stimulants or other serotonin boosting medications like antidepressants [4].




Originally, BZP was synthesised by the Wellcome Research Laboratories as a potential anthelminthic but was found to have antidepressant qualities. However, it was also found that BZP had amphetamine-like qualities and could cause hyperactivity and a reduction in reaction times in 'shock avoidance studies'. It is reported that BZP had about 10% of the potency of dexamphetamine. This led to the cessation of BZP as a potential medicinal drug.

Two separate studies, one by Bye et al (1973) and Campbell et al in the same year were conducted in order to assess the amphetamine-like effects of the drug. The study gave the drug to both healthy people and compared them to former amphetamine addicts. It was found that BZP was very similar to amphetamines.

Recreational use of the drug grew over the 1990's in a number of places including New Zealand and California [1].