Also known as

A2, frenzy, nemesis, pep, euphoria




BZP is a piperazine stimulant that acts similarly to ecstasy. Part of the 'party pills' market that emerged in Europe around 2006, it is taken on its own or commonly in combination with TFMPP, another piperazine-type drug [1].

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 [1].

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 [2].

What does it look like?

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 [3].


Piperazines are a broad class of chemical compounds. BZP is a derivative of piperazine which comes as either hydrochloride salt or free base liquid. The hydrochloride salt is a white solid while the base form is a slightly yellowish-green liquid. The base form is corrosive and can cause burns. Piperazines are also used in the manufacture of plastics, resins, pesticides, brake fluid and other industrial materials [2].


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

Cost £5 - £10 [3].

Why take it?

Sought after effects

  • similar to amphetamines,
  • wakefulness,
  • euphoria [1],
  • feelings of being alert,
  • full of energy [2].

Undesired effects

  • mild headaches,
  • extreme fatigue but inability to sleep,
  • nausea [1],
  • vomiting,
  • stomach pain,
  • dry mouth,
  • agitation,
  • anxiety,
  • irregular heartbeat,
  • diarrhoea,
  • allergic reactions,
  • fever,
  • fits [2].



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

How long do its effects last?

Onset of effects

  • all ROA's - 30 - 45 minutes [5].

Duration of effects



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.

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 [1].

Mode of use

BZP is a stimulant so has effects similar to amphetamines and ecstasy [2].

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 [2].


Taking piperazines does involve risks. Here's what they could do to you.

  • users often suffer a hangover-like reaction that can last for up to 24 hours,
  • agitation, vomiting, stomach pain, fits, irregular heart rhythms, diarrhoea, allergic reactions and fever have been reported,
  • as stimulant drugs, piperazines are particularly risky if taken by anyone suffering from high blood pressure or a heart condition. And you may not know that you have a pre existing heart condition,
  • perfectly healthy young people can have a fit or heart attack after taking stimulant drugs,
  • in rare cases users may suffer from 'Serotonin syndrome'. It can cause high blood pressure and may be fatal [3].

Piperazines and alcohol

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 [3].


  • acute psychosis,
  • renal toxicity,
  • seizures [2].


Long term risks are not yet fully known but may include -

  • respiratory failure,
  • serotonin toxicity [2].


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 [3].

Dangerous interactions


  • 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 [3].

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 [3]

  • 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 [3].

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 [3].

Harm reduction

  • you should avoid using these substances if you have high blood pressure, heart disease, epilepsy (or family history of epilepsy), diabetes or liver problems. Take advice if you are unsure,
  • taking BZP-type pills and dancing in hot clubs can cause dehydration and overheating. Non-alcoholic drinks such as water or isotonic drinks help to prevent this. However, it can be dangerous to drink too much fluid. It is therefore advisable to sip one pint of non-alcoholic liquid (not more) per hour,
  • regular rests from dancing will also reduce the risks of dehydration and overheating,
  • people using BZP-type pills in clubs or at dance events should ensure that they will be looked after in the event of an emergency. It is advisable to go to events that adhere to a safer dancing code of conduct, including adequate ventilation, rest areas, freely available water and staff who are trained to deal with emergencies,
  • it is advisable that only half a pill (if in pill form) is taken first in order to try and determine the potency. Wait for up to 2 hours before re-dosing. If in a powdered form, again only take very little and wait at least 2 hours before considering re-dosing [1].
  • 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].