How Long Does Xanax Stay in Your System?

xanax bars spilling onto table

Xanax, also known by the generic name alprazolam, is a prescription medication used to treat anxiety disorder and panic disorder. While the effects of Xanax typically last for two to four hours, the amount of time the drug stays in the body can vary depending on a number of factors.

Duration of Effects of Xanax

The effects of Xanax typically last between two and four hours. It is known as a short-acting benzodiazepine. Extended-release formulations last between can last anywhere between four and twelve hours.

Xanax Half-Life

The half-life of Xanax is 11 hours. It takes the body about five half-lives to completely remove a drug, so the body removes Xanax in 55 hours (about 2.5 days). Extended-release formulations like Xanax XR are designed to prolong the half-life and make it stay in the body for longer.

The half-life of Xanax XR is 11–16 hours. This may not seem like much longer than immediate-release Xanax, but Xanax XR is designed to even out the peaks and troughs associated with Xanax use. The extended-release version will not make someone as tired and reduces the chances of a “crash” at the end of the dose.

Xanax Drug Test Detection Time

No matter the dose a person takes, Xanax is detectable for about the same amount of time. Common doses for Xanax are 0.25 mg, 0.5 mg, 1 mg, 2 mg. The maximum prescribed dose is 4 mg.

Because of how the body metabolizes drugs, half of it will be broken down in 11 hours, regardless of the starting dose. For example, if someone takes 2 mg at 8:00 a.m., they will have 1 mg in their body at 7:00 p.m. If someone takes 1 mg at 8:00 a.m., they will have 0.5 mg in their body at 7:00 p.m.

In other words, the amount taken will not increase or decrease the drug detection window.

How Long Does Xanax Stay in Your Urine?

Xanax stays in the urine between 3–30 days. For people using Xanax occasionally, it is detectable for three days, but people who use it frequently can expect it to be detectable for several weeks.

How Long Does Xanax Stay in Your Blood?

Xanax stays in the blood for 55 hours. Note that a blood test for benzodiazepines is very uncommon.

How Long Does Xanax Stay in Your Saliva?

Xanax stays in the saliva for three days. Oral fluid (saliva) tests are not common for Xanax and must be ordered specifically.

How Long Does Xanax Stay in Your Hair?

Xanax can be detected in the hair for about 90 days after it was last used.

Factors Affecting How Long Xanax Stays Your System

Xanax stays in the body for different amounts of time depending on several patient-specific factors, including:

  • Age: Older adults tend to metabolize Xanax more slowly.
  • Health: People with liver issues related to alcohol or infection can expect Xanax to be detectable for longer periods because Xanax is processed in the liver.
  • Frequency of Use: Using Xanax more frequently can greatly increase detection time.
  • Method of Use: Little is known about different methods of use like injecting or snorting, but these are thought to affect the amount of time Xanax stays in the body.
  • Presence of Other Drugs: Xanax has a high potential for drug interactions, and some interactions may increase how long it stays in the body.

Can Xanax Cause a False Positive Drug Test?

Yes, false positives for benzodiazepines including Xanax are possible. Drugs that are known to cause false-positives for benzodiazepines include:

  • Sustiva (efavirenz)
  • Daypro (oxaprozin)
  • Zoloft (sertraline)

How Is Xanax Metabolized in the Body?

Xanax metabolism is carried out mostly by the liver. People with liver problems or those with alcohol use disorder may metabolize Xanax more slowly.

Xanax can stay in the blood from a few days to more than a month. The only guaranteed method of passing a drug test is time and sobriety. If you or someone you know is struggling to stop using Xanax, call The Recovery Village Ridgefield. Our team of addiction professionals can answer your questions and guide you down the right treatment path.

DailyMed. “Alprazolam Package Insert.” 2018. Accessed Aug 4, 2019.

Moeller, Karen E., et al. “Clinical Interpretation of Urine Drug Tests.” Mayo Clinic Proceedings, May 2017. Accessed Aug 4, 2019.

Nordal, Kristin, et al. “Detection Times of Diazepam, Clonazepam, and Alprazolam in Oral Fluid Collected From Patients Admitted to Detoxification, After High and Repeated Drug Intake.” Therapeutic Drug Monitoring, 2015. Accessed Aug 4, 2019.