How Long Does Fentanyl Stay in Your System?

Detection Timetable Depends on Many Variables

Fentanyl lozenges
How Long Does Fentanyl Stay in the Body?. © Getty Images News

Several factors are involved in determining how long Fentanyl is detectable in the body, including which kind drug test is being used. Fentanyl - marketed under the brand names Abstral, Actiq, Fentora, and Onsolis - can be detected for a shorter time with some tests, but can be "visible" for up to three months in other tests.

The timetable for detecting fentanyl in the system is also dependent upon each individual's metabolism, body mass, age, hydration level, physical activity, health conditions and other factors, making it almost impossible to determine an exact time fentanyl will show up on a drug test.

The following is an estimated range of times, or detection windows, during which Fentanyl can be detected by various testing methods:

How Long Does Fentanyl Stay in the Urine?

Fentanyl can be detected in the urine for 8-24 hours

How Long Can Fentanyl Be Detected in Blood?

A blood test can identify Fentanyl for up to 12 hours.

How Long Can a Saliva Test Detect Fentanyl?

A saliva test can detect Fentanyl for up to 1-3 days

How Long Can a Hair Test Detect Fentanyl?

Fentanyl, like many other drugs, can be detected with a hair follicle drug test for up to 90 days.

Risk of Fentanyl Overdose

Fentanyl is an opioid analgesic used to treat "breakthrough pain" while the person is already being treated with 24-hour pain medication. It is mostly used for adult cancer patients who are already taking another pain medication but have sudden episodes of pain that breakthrough their regular pain treatment.

Because Fentanyl is usually prescribed to patients already taking other opioid medications, the risk of overdose is greater.

It is important to know how long Fentanyl remains in the system to avoid possible accidental overdose.

The following are some of the symptoms of a Fentanyl overdose:

If you experience any of these symptoms, stop using fentanyl and call your healthcare provider immediately or seek emergency medical treatment.

Illegal Fentanyl Is Much More Dangerous

The information on this page concerning the amount of time fentanyl remains in your body and the risk of overdose are in regards to the legal medication which is used mainly to treat breakaway pain that other medications cannot relieve.

Illegal fentanyl, sold on the street as a powder mixed with heroin or sold as heroin, is much more dangerous than fentanyl used as prescribed. Deaths from overdose from fentanyl have surged in recent years, according to the Centers for Disease Control and Prevention (CDC).

"Fentanyl is a powerful opioid that is 50 to 100 times more potent than morphine, and it is available by prescription, but evidence indicates that illicitly made fentanyl is more likely a powder mixed with heroin and or sold as heroin," said R. Matthew Gladden. a CDC behavioral scientist.

Street drugs can also contain other ingredients that can cause dangerous interactions. One encounter with illegal fentanyl, even accidentally, can prove to be deadly, officials warn.


Always Test Clean. "What Are Drug Detection Times?" Drug Test Facts Accessed December 2015

American Association for Clinical Chemistry "Drugs of Abuse Testing." Lab Tests Online. Revised 2 January 2013.

LabCorp, Inc. "Drugs of Abuse Reference Guide." Accessed March 2013.

OHS Health & Safety Services. "How long do drugs stay in your system?." Accessed March 2013.

U.S. National Library of Medicine. "Fentanyl." Drugs, Herbs and Supplements. July 2012

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