How Long do Benzos Stay in Your System?

Benzodiazepines, commonly referred to as “benzos,” are strong sedatives prescribed to treat anxiety, panic attacks, social phobias, sleep disorders and seizures. These powerful drugs depress the central nervous system activity.

Benzodiazepines are effective for reducing stress and anxiety, encouraging sleep and relaxing muscles. They are also commonly used to decrease the adverse effects of stimulants such as cocaine, speed or ecstasy and to help mitigate withdrawal symptoms from other depressants like alcohol or heroin.

Some common benzodiazepines are:

Shorter-acting (generic names followed by brand names if available):

  • Alprazolam (Xanax)
  • Estazolam
  • Lorazepam (Ativan)
  • Midazolam (Versed)
  • Oxazepam
  • Temazepam (Restoril)
  • Triazolam (Halcion)


  • Chlordiazepoxide
  • Clobazam (Onfi)
  • Clonazepam (Klonopin)
  • Diazepam (Valium)
  • Flurazepam

How Do Benzodiazepines Work?

Benzodiazepines work by attaching to certain receptors in the brain, called gamma-Aminobutyric acid (GABA) receptors. This receptor normally causes an inhibitory effect in the brain and nervous system, and when activated by a benzodiazepine, even more inhibition occurs. This effect causes relaxation, sleepiness and decreased seizure activity in people who have seizure disorders.

How Long Do Benzodiazepines Remain in the Body?

Different types of benzodiazepines can remain in the body longer than others. By measuring peak levels and half-lives, we can better understand how long a drug stays in the body. A peak level is the maximum concentration reached in the bloodstream and the half-life is the time it takes for one-half of the dose to be eliminated by the body.

Benzodiazepine peaks and half-lives vary depending on several factors, like the size of the dose, how frequently the dose is taken, and route of administration. In general, benzos can be divided into three categories:

  1. Short-acting: The half-life of short-acting benzodiazepines is about two to five hours.
  2. Medium-acting: The half-life of medium-acting benzodiazepines is about 10 to 24 hours.
  3. Long-acting: The half-life of long-acting benzodiazepines is usually over 24 hours. This group has metabolites (breakdown products) that form and release in the body, which still have similar benzodiazepine activity as the original drug. Also, these metabolites can build up in the body, effectively causing the drug to remain in the body for long periods.

Benzodiazepine Half-Lives

Knowing the half-life of a particular drug can help determine how long it will stay in the body. Generally, once four to five half-lives have gone by, the drug is mostly out of the person’s system. For example, for a drug with a half-life of three hours, after 12 to 15 hours of ingestion, most of the drug will be gone. Although this principle gets more complicated when drugs have complex metabolism processes, it’s a good general rule. Some benzos also come in an extended-release form, which means they take longer to exit the system after ingestion.

This list shows the half-lives of the more common benzodiazepines:

How Long do Benzos Stay in Urine, Blood and Hair?

Each benzodiazepine has different chemical properties, so the time they remain detectable in blood, urine or hair varies from drug to drug. These times vary from person to person as well, due to the individual’s metabolism rate, frequency of dosing and size of doses. Some rough estimates are:

Find Treatment for Benzo Addiction

Seeking medical attention for benzodiazepine addiction is important. Medical detox in a treatment facility such as The Recovery Village Ridgefield can help you achieve success with your recovery. Stopping benzodiazepine use abruptly can cause seizures and even death in some cases. The process of the initial benzodiazepine detox is important and should be followed up with professional treatment to establish long-term recovery.

If you or someone close to you needs assistance in overcoming benzodiazepine addiction, call The Recovery Village Ridgefield Detox Center to speak to a representative about how treatment can work for you.

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