All drug use has risks. This page is for information only and does not constitute or replace medical advice. If you have medical concerns about your drug use, please speak to a medical professional.

Benzodiazepines are a group of tranquilliser drugs, with sedative (calming) effects, legal when prescribed

Other names

benzos, Vallies, blues, diazepam , downers


Tablets or capsules in various shapes, sizes and colours.

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Misuse of Drugs Act (1971) - Class C.

(unless prescribed by a doctor)

Penalties for possession without a prescription are up to 2 years in prison and/or an unlimited fine. Penalties for supply are up to 14 years in prison and/or an unlimited fine.

How it’s taken

Most commonly swallowed


Licensed tablets are produced with an active dose of 2 milligram (mg), 5 mg or 10 mg (these doses should not be taken as a recommendation): duration and effects will depend on purity, whether the drug is licensed or not, your body and the route of administration.

General information on dosing.


Benzodiazepines can cause drowsiness and long periods of sleep. They slow down your heart rate and breathing. People taking them can experience a ‘floating’ sensation as well as a warm, calm and relaxed feeling. Other effects can include lack of coordination, slowed speech, blackouts, short-term memory loss, reduced mental alertness and anxiety.

Benzodiazepines can also reduce anxiety and therefore impair your judgement of danger. This makes people care less, and can result in risky behaviour.

However, some people taking benzodiazepines, particularly at higher doses, can experience increased anxiety, seizures or ‘fitting’, aggression and other negative symptoms.

Withdrawal symptoms can happen even after short periods of use. Avoid taking for more than 4 weeks. With prolonged use, withdrawal effects can be severe and may include headaches, seizures (fits) nausea, extreme anxiety, depression, paranoia and delusions (very strong beliefs that other people don’t share). The severity of the symptoms will vary depending on the amount of drug used but symptoms will ease with time. During this time, to help the body recover, a healthy diet, fresh air, light exercise can help. Try to resist taking more of the drug, or other drugs (including alcohol) to deal with the withdrawal symptoms.

Stopping after longer term use requires a steady reduction of dose (tapering) and support: stopping suddenly and completely can be fatal. Your GP or local drug service can help with this.


  • Use can lead to memory loss
  • Tolerance develops quickly which can lead to people using more over time, increasing the risk of dependence and overdose
  • Withdrawal symptoms can happen after even short periods of time
  • Increased risk of overdose if mixed with alcohol, opiates (like heroin) or opioids (like methadone) or other depressant drugs

Harm reduction

If you choose to take benzodiazepines then the following steps can help to reduce harm.
  • Avoid mixing benzos with alcohol, prescription drugs and other drugs, especially other depressants/downers such as alcohol, diazepam and gabapentin and opioids such as heroin and methadone. All of these drugs can depress breathing resulting in a serious risk of death if mixed.
  • Naloxone will not reverse a benzodiazepine only overdose. If you suspect that someone has taken opiates then administer naloxone.
  • If you see someone seriously affected after a high dose, e.g. cyanosis (blue lips) loss of consciousness, agonal (noisy, rasping, slow) breathing, call 999 and tell the paramedics what they have taken.
  • Avoid taking benzos alone and stay with friends in case you experience negative effects.
  • Sleep on your side to avoid choking in your sleep if you throw up.
  • Strength can vary, even between pills from the same batch/packet if unlicensed/not prescribed, or pills which look the same. Start with a small test dose and wait at least 2 hours before re-dosing.
  • It is easy to build a tolerance to benzodiazepines.
  • Withdrawal symptoms can happen even after short periods of use. Avoid taking every day and take regular breaks from use.
  • Avoid taking other drugs or more benzodiazepines to deal with withdrawal symptoms.
  • If symptoms become distressing seek medical help and in an emergency call 999.
  • Benzos impair reaction times. Avoid driving or using heavy machinery whilst under the influence.
  • Remember that taking a benzodiazepine won’t simply cancel out the effects of stimulants or other drugs – it may make their effects more unpleasant.
  • The short-lasting effect of some benzos can encourage people to take it frequently or take more than they need. Be aware that although you may not feel the effects, the drug is still present in your body so avoid re-dosing too frequently to avoid overdose and death.

Detection time

People taking benzodiazepines have reported the following detection time, but this cannot be taken as a recommendation; detection of any drug will depend on purity, regularity of use, other medications or drugs you have taken, your body and how it’s taken.
  • For 2-28 days in urine and potentially up to 6 weeks with regular heavier use