Benzodiazepine facts

In this article, we take a closer look at benzodiazepines, what they are, how they are used, the side effects of benzodiazepine use and more.

What are benzodiazepines?

Benzodiazepines are sedative medications (depressants) that slow down the functions of the brain and the body.

These types of drugs can be legally prescribed to alleviate symptoms of conditions like insomnia (difficulty getting to and/or staying asleep) and anxiety.

Examples of prescribed benzodiazepines include diazepam (Valium), alprazolam (Xanax), flurazepam (Dalmane).

Illegally-manufactured benzodiazepines, also known as ‘street benzos’, are sometimes sold in counterfeit packaging to make them look like branded medications. However, they are most often sold illegally in pill form.

What do benzodiazepines look like?

Illegally-manufactured benzodiazepines are commonly sold in tablet, capsule, or injectable forms, and come in a wide variety of colours.

How are benzodiazepines used?

Benzodiazepines are usually ingested in tablet or capsule form. However, in rare instances, they can also be injected.

Prescribed benzodiazepines may also be administered rectally (in the form of a suppository).

How do people behave when they take benzodiazepines?

How a person feels and behaves after using benzodiazepines can vary, depending on the person.

These types of drugs depress the nervous system, slowing down the brain and body. Some people use benzodiazepines to help them ‘come down’ after taking stimulants (e.g. ecstasy).

What are the side effects of benzodiazepines?

The physical side effects experienced when taking benzodiazepines can depend on several factors including how the drugs are ingested, frequency of use, and the metabolism and weight of the person.

Some common side effects include:

  • Slower reflexes
  • Drowsiness
  • Clumsiness
  • Confusion

Frequent use of benzodiazepines can lead to withdrawal symptoms including nausea, vomiting, anxiety, panic attacks and depression.

What happens when you use benzodiazepines with other drugs

Below is an overview of the side effects of using benzodiazepines alongside other drugs.


Drinking alcohol while taking benzodiazepines can cause shallow breathing and sedation, significantly increasing the risk of overdose and even death.


Because cocaine is a ‘stimulant’ or ‘upper’ and benzodiazepines are ‘depressants’ or ‘downers’, combining these substances can have unpredictable adverse effects.


Mixing heroin with benzodiazepines can cause respiratory depression, sedation, numbness, reduced heart rate, and other serious side effects.

What legislation covers benzodiazepines?

Prescribed benzodiazepines including diazepam (Valium), alprazolam (Xanax) and flurazepam (Dalmane) are controlled substances under Schedule 4, Part 1 of the Misuse of Drugs Act 1977.

While it is lawful to possess benzodiazepines that have been legally prescribed, it is an offence to obtain, ‘give away’ or sell them without a valid prescription.

This means that the illegal possession, sale, or supply of any of these substances is prohibited. Anyone who commits one of these offences could be liable for a fine, prison sentence, or both.

Are benzodiazepines used in medicine?

Benzodiazepines are prescribed by doctors in Ireland for short periods to treat certain conditions including anxiety, depression and sleep problems (e.g. insomnia).

They can also be used in the treatment of alcohol dependency, to help manage withdrawal.

How long does it take for benzodiazepines to show up in a drug test?

Even after the ‘high’ has worn off, and long after the drug was first consumed, benzodiazepine use can be detected by a drug test, depending on the type of test you take.

The drug testing detection windows for benzodiazepines are as follows:

  • Oral fluid (saliva) – up to 48 hours
  • Urine – up to 4 days
  • Hair – up to 12 months (depending on the length of hair available)
  • Nails – up to 12 months (up to 6 months for fingernails and up to 12 months for toenails)

Oral fluid and urine drug testing are known as ‘narrow-window’ forms of testing and can be used to detect drug use from 30 minutes after consumption, up to a few days.

This can vary depending on the type of substance and how much was used.

The rate at which hair and nails grow means that both hair drug testing and nail drug testing can provide a ‘wide-window’ of detection for drugs and their metabolites (up to 12 months).

Where can I buy a drug test?

Our Home Drug Testing Kit has been designed to give you peace of mind or enable you to seek support for a friend or loved one who is struggling with substance misuse.

This easy-to-use, self-contained screening kit can detect drugs and their metabolites in a urine sample, with built-in test strips that allow you to read the results in just 5 minutes

Please be aware that our home drug test kits are for peace of mind only, and the results cannot be used in court. If you require a drug test for official matters, you will need a legally-instructed drug test.

For confidential advice about which test might best suit your needs, you can also call our Customer Services team on 01 402 9466 or email

Home Drug Testing Kit

Order your home drug testing kit online now for just €20.

Marie Law AlphaBiolabs

Marie Law

Head of Toxicology at AlphaBiolabs

A highly-skilled and respected scientist with over 13 years’ experience in the field of forensics, Marie joined AlphaBiolabs in 2022 and oversees the company’s growing toxicology team.

As Head of Toxicology, Marie’s day-to-day responsibilities include maintaining the highest quality testing standards for toxicology and further enhancing AlphaBiolabs’ drug and alcohol testing services for members of the public, the legal sector, and the workplace sector.

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