How long does Fentanyl stay in the system?

It can take your body several days to eliminate Fentanyl. How dangerous is Fentanyl and what does detox from Fentanyl feel like? More here.

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Reviewed by: Dr. Dili Gonzalez, M.D.

When used by medical professional, and as prescribed, Fentanyl can be an effective means of treating chronic or extreme pain. However, it’s effectiveness makes it an appealing target for opiate addicts. And Fentanyl is increasingly tested for use as a drug of abuse.

Q: So, how long does it take for the body to eliminate Fentanyl? How long can it be detected in drug tests?
A: Fentanyl can take anywhere from a day to two days (or sometimes more) to leave the system.

Continue reading to learn about Fentanyl’s duration and addictive potential. Your questions are welcomed in the section at the end of the page, and we try to answer personally, as soon as possible.

What is Fentanyl, and is it dangerous?

Fentanyl is a Schedule II opiate medication, meaning it has some medicinal value but also possesses a high risk for abuse. It is intended for use with pain relief in hospitals or for patients with chronic and severe pain issues. However, the opiate epidemic has turned Fentanyl and its synthetic analogs into lethal threats comparable to heroin and other street drugs.

Fentanyl and illegally-produced Fentanyl copycats have acted as gasoline on the fire of the opiate epidemic. Fentanyl is 50-100 times more powerful than morphine, and 30-50 times more potent than heroin itself. This puts even experienced heroin users at risk of Fentanyl overdose if taken in excess. Further, in “street mixes” of heroin and Fentanyl, oftentimes the ratio of Fentanyl to heroin is totally unknown, which could also lead to overdose.

Fentanyl and Fentanyl-laced heroin have many street names, including Apache, China girl, China white, dance fever, friend, goodfella, jackpot, murder 8, TNT, Tango, and Cash.

How does Fentanyl work?

Fentanyl activates the opiate receptors in the brain, particularly in areas of the brain that process emotions and pain sensitivity. Does Fentanyl get you high? When you take any opiate, including Fentanyl, it increases the amount of free-floating dopamine in these parts of the brain, producing a “high” feeling, or sensation of euphoria. However, it also seriously affects the parts of the brain responsible for some critical life functions such as breathing and heart rate. The way that opiates cause death when taken in excess (i.e., overdose) is the depression of respiration- essentially. An overdose can cause the user to stop breathing, which leads to brain damage and death if not reversed in time.

How long does Fentanyl stay in the system?

In general, the answer to this question depends on a host of factors:

  • How much Fentanyl has been taken
  • The route of administration
  • How long of a time period it has been taken for
  • Subjective factors such as height, weight, gender, general health, and drug history

If Fentanyl has been administered intravenously (IV), for example, it clears from the body’s system much faster than if it has been taken transdermally (i.e., the patch) or transmucosally (i.e., lozenges). IV Fentanyl is usually cleared from the body in roughly 11-22 hours, depending on the other interacting factors.

Other administration methods can take up to a day and a half or two days.

However, as Fentanyl breaks down it leaves behind traces called “metabolites”, and these can be shown in plasma or urine screens for an even longer period of time. This means that a particularly thorough drug test could detect use even after several days of “staying clean”.

Is there a way to rapidly detox from Fentanyl?

There are some facilities that advocate for “Rapid Detox”, which is typically anesthesia-assisted withdrawal. The patient or addict is sedated under medical supervision while they are put into immediate medical withdrawal from a drug by use of an opiate blocker. However, this procedure can be expensive and is rarely covered by insurance companies. Further, studies have shown that this method does not produce any significant reduction in withdrawal discomfort compared to any other methods.

What is Fentanyl detox like?

Like any other opiate, detoxing from Fentanyl is not a pleasant experience. When medically supervised, detox is typically safe, and many side effects can be alleviated with other medications. When do you start withdrawing from Fentanyl? If you’ve developed dependence on Fentanyl, you’ll begin withdrawal close to your next expected dose n the first 24 hours after last use.

Additionally, if an addict is detoxing in a non-medical environment, without proper care and assistance, the symptoms can be severe and debilitating. When your body is used to receiving any drug on a regular basis, it can develop physical dependence, meaning the removal of that drug “throws off” the body and creates a host of unpleasant symptoms. Fentanyl withdrawal can cause:

  • chills
  • extreme nausea
  • gastrointestinal cramping
  • insomnia
  • irritability
  • muscle and bone discomfort or pain
  • restlessness
  • severe anxiety
  • sweating

Questions about Fentanyl?

You can learn more about Fentanyl Addiction Treatment programs and help options if you or a loved one are in need of professional medical assistance. If you still have questions about how Fentanyl affects the body and can be traced…please leave them in the comments section below. We’ll do our best to respond to you personally and promptly.

Reference Sources: DEA: Drug Chem Info for Fentanyl
DEA: Drug Diversions
NIDA: Withdrawal not easier with ultrarapid opiate detox
Mental Health Daily: How long does Fentanyl stay in your system


About the author
Heather King, Ph.D., completed her graduate studies in preclinical substance abuse research in July of 2015. She has authored several peer-reviewed publications in scientific journals on the effects of drug abuse on the brain and behavior, and has personal experience in addiction and recovery. She currently works at Serenity Acres, a drug and alcohol treatment center outside of Annapolis, MD.
Medical Reviewers
Dr. Dili Gonzalez, M.D. is a general surgeon practicing women's focused medici...

All of the information on this page has been reviewed and verified by a licensed medical professional.

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