How Long Does Xanax (Alprazolam) Stay in Your System?

valium and xanax


Xanax (alprazolam) is a benzodiazepine medication that's used to treat anxiety disorders, panic disorder, and panic attacks. It's also sometimes prescribed for depression and other conditions like agoraphobia and severe premenstrual syndrome. Xanax works by slowing down your nervous system, giving you a calm feeling. Because it can be habit-forming, it's used as a short-term treatment. You may want to know how long Xanax remains in your system so you can avoid side effects, interactions with other medications and substances, and accidental overdose.


Xanax is considered an intermediate-acting benzodiazepine drug. After taking Xanax in pill form, peak levels are found in your blood 1 to 2 hours later. The average half-life of Xanax in the blood is 11.2 hours in healthy adults, meaning that half of the drug has been metabolized and eliminated in the urine in that time frame. It takes five to seven half-lives for 98 percent of a drug dose to clear the body, so Xanax takes at least four days to be fully eliminated from the body.

The half-life is longer for the geriatric population, obese people, those with alcoholic liver disease, and people with Asian genetics. This means that Xanax takes more time to metabolize and clear out of your system. Meanwhile, the concentration of Xanax in the blood is up to 50 percent less in smokers.

Detection Windows

Xanax is detectable in your blood, urine, saliva, and hair, but how long it's detectable depends on a variety of individual factors. Your age, weight, body fat, other medications, dose, length of time taking Xanax, hydration level, and metabolism all affect how long it takes for the drug to be eliminated from your system.

Here are the approximate detection window times for Xanax:

  • Urine: A urine drug screen, such as those that are done for employment, will test positive for benzodiazepines for five days and up to a week after a dose. For populations who metabolize Xanax more slowly—elderly, obese, Asian, and those with alcoholic liver disease—that time maybe even longer.
  • Saliva: Xanax can be detected in saliva for up to 2.5 days.
  • Hair: As with all drugs, Xanax can be detected in your hair starting two to three weeks after and for up to 90 days after your last dose.
  • Blood: Blood levels may be done as a screening test or in cases of treatment for a suspected overdose, but they can only tell if you've taken Xanax in the last 24 hours.

If you are taking Xanax and you have a drug screening or test, tell the testing laboratory so they can properly interpret your results. If you're being screened at work, you may want to let your employer know that you're taking Xanax ahead of time.


There are certain potential risks while taking Xanax, including:

  • While you're taking Xanax, you may be drowsy and sedated, so don't drive, operate machinery, or perform any other activity or task that requires your full concentration.
  • Xanax can harm your fetus if you're pregnant, so talk to your doctor if you become pregnant or you're planning to become pregnant while taking Xanax.
  • Interactions with other medications can lead to serious, life-threatening breathing problems, sedation, and coma while you are taking Xanax. Discuss with your doctor all prescription and over-the-counter medications you're taking, plan to take, or plan to discontinue. Some medications of special concern are opiate medications such as codeine, hydrocodone, fentanyl, hydromorphone, meperidine, methadone, morphine, oxycodone, and tramadol.
  • Drinking alcohol and/or using illegal drugs makes the chances of life-threatening side effects even higher. You'll need to avoid alcohol and street drugs while you're taking Xanax.
  • Because Xanax can create feelings of relaxation, calm, and well-being, and because it doesn't take long before your body becomes tolerant to the dose you're on, it has the potential to be extremely habit-forming. Your doctor will likely start you on the lowest dose possible to see if it's effective and keep you on the lowest effective dose. Make sure you only take Xanax as directed; don't take it more often, take a bigger dose, or keep using it longer than your doctor has instructed.
  • You may experience withdrawal symptoms if you suddenly stop taking Xanax. Don't stop or decrease your dose on your own as this can actually be dangerous. Talk to your doctor, who will prescribe an appropriate tapering schedule that will minimize or eliminate any potential withdrawal symptoms.

Common Side Effects

Xanax can cause side effects that often go away once your body gets used to the medication. The most common side effects include:

  • Drowsiness
  • Fatigue
  • Feeling lightheaded
  • Dizziness
  • Headache
  • Dry mouth
  • Erectile dysfunction and/or other sexual performance or interest issues
  • Nausea
  • Constipation
  • Appetite changes
  • Joint pain
  • Nasal congestion

Let your doctor know if these side effects don't go away or they're severe.

Serious Side Effects

Serious side effects aren't very common, but if you experience any of the following while taking Xanax, call your doctor right away:

  • Difficulty breathing
  • Seizures
  • Hallucinations (hearing or seeing things that aren't real)
  • Severe rash on your skin
  • Yellow-ish eyes or skin
  • Problems with memory
  • Speech difficulties
  • Confusion
  • Coordination problems
  • Depression
  • Suicidal thoughts
  • Mood changes that aren't normal for you


Take your prescription on the schedule and dosage your doctor prescribed. Do not cut or crush extended-relief pills as this gives you a larger dose all at once and may cause an overdose.

Symptoms of Xanax overdose can include:

  • Drowsiness
  • Shallow respiration
  • Clammy skin
  • Dilated pupils
  • Weak and rapid pulse
  • Confusion
  • Coma

If you suspect that someone has taken an overdose of Xanax, call 911 or the Poison Control Center at 1-800-222-1222.

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Article Sources

  1. Nordal K., Øiestad E.L., Enger A., Christophersen A.S., Vindenes V. (2015) Detection times of diazepam, clonazepam, and alprazolam in oral fluid collected from patients admitted to detoxification, after high and repeated drug intakeTherapeutic Drug Monitoring , 37, 451–460. doi:10.1097/FTD.0000000000000174

Additional Reading

  • Mayo Medical Laboratories. Benzodiazepines. Mayo Foundation for Medical Education and Research. Mayo Clinic.

  • MedlinePlus. Alprazolam. U.S. National Library of Medicine. Updated July 30, 2018.

  • United States Food and Drug Administration (FDA). Xanax. Updated September 2016.