How Long Do Benzos Stay in Your System?
Benzodiazepines, also known as benzos or downers, are prescription medications that are commonly used to treat anxiety, muscle spasms, insomnia and seizures. There are many different medications in the benzodiazepine drug class, and each one has specific characteristics that can affect how long they are present in the system.
What Are Benzos?
Benzodiazepines are depressants, meaning they work by slowing down signals between the brain and the body. Combining benzodiazepines with other depressants, such as alcohol, cannabis or heroin, can lead to life-threatening side effects like breathing difficulties and overdose. Benzodiazepines are among the most commonly misused and misprescribed medications worldwide.
Benzodiazepines can be used to treat alcohol withdrawal, epilepsy, anxiety or insomnia, and they can also be used as a sedative during procedures. However, benzodiazepines carry the risk of abuse, dependence and addiction, which is why they are classified as Schedule IV controlled substances. Due to these risks, doctors typically prescribe the lowest dose possible and avoid long-term prescriptions.
Examples of commonly prescribed oral benzodiazepines and their brand names include:
- Alprazolam (Xanax)
- Chlordiazepoxide (Librium)
- Diazepam (Valium)
- Lorazepam (Ativan)
- Temazepam (Restoril)
How Are Benzodiazepines Metabolized?
Benzodiazepine metabolism can vary depending on the medication taken. For specific information, it’s best to refer to your doctor or pharmacist. In general, benzodiazepine medications are metabolized by the liver and then excreted in urine.
A drug’s half-life is how long it takes for the body to metabolize and eliminate half of the drug after a single dose. It can take three to five half-lives for a drug to be completely removed from the body after a single dose. However, it can also take longer if the drug is used at high doses or for a long time.
How Long Do Benzos Last?
The half-life of a benzodiazepine can be affected by a person’s age, weight, liver function, kidney function and frequency of use.
The half-lives of commonly prescribed oral benzodiazepines include:
- Alprazolam (Xanax): Six to 20 hours
- Chlordiazepoxide (Librium): Five to 30 hours
- Diazepam (Valium): 20 to 100 hours
- Lorazepam (Ativan): 10 to 20 hours
- Temazepam (Restoril): Eight to 22 hours
Will Benzos Show up on a Drug Test?
As with drug testing for many other drugs and medications, benzodiazepine testing typically determines the presence of the metabolite, or chemical byproduct, of benzodiazepines. Many commonly abused benzodiazepines are metabolized to oxazepam, which is also available as a prescription medication. For this reason, it is not always possible to tell which benzodiazepine was taken.
The ability to detect benzodiazepines on a drug test depends on the method of testing (urine, blood, saliva or hair) and the person’s age, weight, liver and kidney function, frequency of use and type of benzo used. The only sure way to pass a drug test is to avoid using benzodiazepines.
How Long Will Benzos Stay in Your Urine?
Benzodiazepines are extensively metabolized in the body and then excreted in the urine. The most common technique used to test for benzodiazepines in urine involves immunoassay methods, which are designed to detect oxazepam or other structurally similar benzodiazepines. Because many benzodiazepines are metabolized using a similar pathway in the body, it is possible to test positive for benzodiazepines without knowing which benzodiazepine was ingested.
Benzodiazepines may be detectable in the urine for up to 8 days, depending on the benzodiazepine.
How Long Do Benzos Stay in Your Blood?
Benzodiazepines may be detectable in the blood for 4-200 hours, depending on the benzodiazepine.
How Long Do Benzos Stay in Your Saliva?
Benzodiazepines may be detectable in saliva for up to 50 hours after ingestion.
How Long Do Benzos Stay in Your Hair?
Hair testing is unique because it measures the last 90 days of drug use. Since hair grows at a fixed rate of about 0.5 cm per month, hair drug tests can look back three months by taking 1.5 cm of hair. Hair tests have the longest detection window but can be expensive and are not used often. Some benzodiazepines can be detected using this method, but others cannot.
False Positives for Benzodiazepines
A positive result means that a metabolite of benzodiazepine metabolism is found. However, there are instances when a different medication has a chemically similar metabolite and can cause a positive test result even though you have not taken benzodiazepines. This is called a false positive.
Two common medications that might result in a false positive for benzodiazepines are some non-steroidal anti-inflammatory medications (NSAIDs) or the antidepressant sertraline, a selective serotonin reuptake inhibitor (SSRI). It’s estimated that over 30 million people worldwide use NSAIDs on a daily basis and 13.2% of American adults use an antidepressant.
Over-the-Counter Drugs That Test Positive for Benzodiazepines
Over-the-counter (OTC) medications that have been shown to result in false-positive tests for benzodiazepines include naproxen and ibuprofen.
A positive result will always be confirmed with liquid or gas chromatography/mass spectrometry (LC-MS or GC-MS). These tests are very sensitive and specific, and they can measure the individual “fingerprint” of a drug.
False Negatives for Benzodiazepines
False negatives occur when a test does not detect benzodiazepines even though it should. The rate of false negatives can vary depending on which benzo is being taken. For benzodiazepines, the false-negative rate in an immunoassay screen is approximately 25% to 30%. There are many factors that can affect this, including the cutoff (or sensitivity) of the test, the type of benzodiazepine used and how many/which metabolites the test is measuring for.
Factors that Affect How Long Benzos Stay in Your System
Individual characteristics play a large role in the metabolism of benzodiazepine drugs. These include:
- Age: Older adults have a shift from muscle (lean) tissue to more fat (lipophilic) tissue. For this reason, benzos can accumulate and stay in the body for longer.
- Weight and body fat: Many benzodiazepines are lipophilic, meaning they dissolve and stay in fat tissue. Because of this property, people at higher body fat percentages may accumulate benzodiazepines for longer than people with more lean muscle.
- Type of benzo taken: This has the biggest impact on detection time. In general, the benzodiazepines that are detectable for the longest amount of time are clonazepam (Klonopin), diazepam (Valium) and flurazepam (Dalmane).
- Liver and kidney function: Most benzos are broken down by the liver, so someone with impaired liver function will store the drug in their body for longer. Some benzos may also be excreted by the kidneys, which means that impaired kidney function can also affect storage time.
- Frequency of use: More frequent benzo use lengthens detection time.
When stopping benzodiazepines, the body and brain have to become used to functioning without the medication. It is important to discuss stopping benzodiazepines with your doctor, as abruptly quitting can cause seizures and other dangerous withdrawal symptoms.
Benzo Withdrawal Symptoms
Timing and severity can depend on a variety of factors, including age, weight, type of benzo taken, liver and kidney function and frequency of use. Some symptoms of benzodiazepine withdrawal include:
- Aching or twitching muscles
- Dizziness and tremors
- Nausea, vomiting, stomach pains
- Bizarre dreams, difficulty sleeping, fatigue
- Poor concentration
- Anxiety and irritability
- Altered perception, heightening of senses
- Delusions, hallucinations and paranoia
Withdrawal symptoms can last from a few weeks to a year. People who have used high benzo doses over the long term are typically at the highest risk for severe withdrawal. It is estimated that seizures may occur in as many as 20% to 30% of individuals undergoing untreated withdrawal from these substances. For this reason, it is often best to attend a medically assisted detox program when severe withdrawal symptoms are expected.
As Schedule IV controlled substances, benzodiazepines carry the risk of abuse, dependence and addiction. These concerns can create many negative changes in a person’s life and damage relationships, careers and finances. For many people, benzodiazepine abuse and addiction can be incredibly difficult to recover from alone. Fortunately, professional addiction treatment programs can help make the journey easier.
Benzo Addiction Treatment
If you or a loved one struggle with benzodiazepine addiction, The Recovery Village Ridgefield can help. Our 80-bed facility sits on five acres of land to provide you with a safe environment to promote lifelong recovery from addiction. We offer many levels of care to serve you, including medical detox, inpatient care, partial hospitalization programming (PHP), outpatient treatment, telehealth and aftercare planning.
If you or someone you love is struggling with benzodiazepine abuse, The Recovery Village Ridgefield can help. Contact us today to learn about safe and effective benzodiazepine detox and addiction treatment programs that can work well for your needs.
Medical Disclaimer: The Recovery Village aims to improve the quality of life for people struggling with a substance use or mental health disorder with fact-based content about the nature of behavioral health conditions, treatment options and their related outcomes. We publish material that is researched, cited, edited and reviewed by licensed medical professionals. The information we provide is not intended to be a substitute for professional medical advice, diagnosis or treatment. It should not be used in place of the advice of your physician or other qualified healthcare provider.