Are you or a loved one looking for a sober living program? Give us a call! 424-327-4614

Are you or a loved one looking for a sober living program?  Give us a call!

How Long Does Fentanyl Stay in Your Urine?

Medically Reviewed by: Charley Allen

Table of Contents


How Long Does Fentanyl Stay in Your Urine

Fentanyl addiction is prevalent throughout the United States. Fentanyl, a prescription opioid that is most commonly prescribed to treat severe and chronic pain, can be useful in a medical context. Unfortunately, this synthetic opioid, which is 50-100 times more powerful than morphine, very rapidly leads to physical dependency. According to the National Institute on Drug Abuse, roughly 29% of people who are prescribed prescription opioids like fentanyl end up abusing them, and 8% to 12% develop an opioid use disorder. A variety of illicit labs run by criminal organizations also produce their own fentanyl, which can be even more potent. Illicit fentanyl analogues such as carfentanil can be 10,000 times more potent than morphine. Fentanyl compared to heroin is many, many times more potent. Drug overdoses due to synthetic opioids have in fact surpassed heroin deaths and are continuing to increase with each passing year.

Young people are particularly susceptible to fentanyl overdose and fentanyl dependence. This may come as some surprise, given that young people rarely suffer from the severe and chronic pain that fentanyl is designed to treat. However, the unfortunate truth is that it is quite easy for a young adult or college student to take fentanyl accidentally! This is because drug dealers and distributors routinely add fentanyl to other drugs, such as heroin, crystal meth, cocaine, and sometimes unlabeled opioid pills. While many college students who are aware of fentanyl reputation may deliberately avoid it, it is not uncommon for young people to experiment to some degree with recreational drugs. Your child may have unwittingly consumed fentanyl and become addicted. The consequences of fentanyl addiction can be devastating: many turn to street drugs, suffer severe interpersonal and academic consequences, and develop debilitating physical and mental health disorders. Worse yet, they may overdose and die.

If you suspect that your child may be abusing fentanyl, it is important to administer a home drug test. Drug tests are routinely used by employers, academic institutions, hospitals, and sober living homes to ensure continued sobriety. The United States’ legal system also administers drug tests. For criminal offenders who want to avoid serving time, a fentanyl drug test during probation can be all that stands between them and jail. Rather than wait until your child’s substance use disorder has progressed to the point where they are facing academic, work, health, or legal consequences, it is a good idea to test them in the safe environment of the home.

There are many types of drug tests available that analyze different samples from a person’s body for signs of drug use. These include blood tests, hair tests, saliva tests, and urine tests. Urine tests are by far the most affordable, easiest to use at home, and they have a high degree of accuracy. Nonetheless, even among urine drug test kits, there is wide variation. Not all drug test kits measure for the presence of all drugs. Fentanyl is an opioid, but you may be surprised to learn that opioid tests often fail to detect oxycodone, oxymorphone, meperidine, and fentanyl. The question you should ask yourself when you’re purchasing a test kit should be: will fentanyl show up? Do your research, and make sure you are buying a legitimate fentanyl drug test kit.

Administering a Fentanyl Urine Test

When you have determined that your child may be using fentanyl, it is time to prepare for testing them. The first thing to remember is that individuals who suffer from drug addiction are notoriously secretive about their drug dependence. Most experience some degree of shame about their condition. Many are convinced that it is their responsibility to manage it themselves. It is also very common for young people to shy away from those trying to help them. Why? They want to keep abusing opioids. The idea of quitting and going through withdrawal is a frightening, painful thought. For these reasons, the majority of young people will do their best to avoid testing positive for fentanyl. A variety of methods for cheating on fentanyl tests are often utilized. To prevent an inaccurate result, it is important that parents do not inform their child in advance that they will be tested on a specific date. Doing so gives them time to prepare a scheme to cheat the test. Instead, spring the test at a random and unpredictable time, ideally when they seem impaired.

How does a fentanyl drug test kit work? The first step of a fentanyl test is the test-taker involves the test-taker providing a sample of their urine. Once provided, the test administrator should prevent the sample from being contaminated, which can decrease the accuracy of the fentanyl and urine drug screen. The sample can then be applied to the collection site, which is included with the fentanyl urine test kit. After a short wait, the collection site will indicate whether or not there are traces of the drug in the fentanyl and urine drug screen. Most tests have two lines. The first line is a control line that lets administrators know the test is working. The second line is known as the test line. If the test line remains present, even if it is barely detectable, that means that the test-taker has tested negative for fentanyl. If the line has disappeared entirely, however, that means that traces of fentanyl were detected in their urine.

However, it is important to remember that fentanyl drug test kits are not 100% accurate. It is possible, first of all, for a test-taker to get a false positive. Contaminants in the urine sample can alter results. Consuming certain foods and beverages, such as poppy seeds, before taking the test can also result in a false positive. False positives are relatively rare. It is perhaps more important to be wary of false negatives, which can allow a drug user to continue endangering themselves without being detected.

How Do People Deceive Fentanyl Urine Tests?

False negatives can occur when a person deliberately cheats on their fentanyl urine test. Methods of cheating on a fentanyl test include:


This method involves replacing the urine sample with a sober person’s urine sample. A number of artificial urine products are also frequently used for this same purpose.


Dilution involves decreasing the proportion of fentanyl metabolites in the pee relative to its water content. The easiest way to do this is to drink high quantities of water before taking the fentanyl urine test.


Young people may sometimes contaminate their urine samples with household products or commercially available industrial chemicals. These include vinegar, bleach, iodine, detergent, isopropyl alcohol, nitrite, glutaraldehyde, and pyridinium chlorochromate. Doing so prevents the test from measuring drug metabolites accurately.

Will Fentanyl Show Up on Your Test Anyway?

It must be emphasized, however, that even if your child has not cheated and they continue to test negative for fentanyl, that does not mean that they are drug-free. It is possible that they are taking a different drug not measured by the particular drug testing kit you used. It is crucial to read the instructions and understand the limitations of the drug kit you’re using to interpret the results properly. It is also important to understand that every drug testing kit can only test for a specific period of time. Your adult child may in fact be using fentanyl despite testing negative. In that case, it is possible that a sufficient period of time passed between their last usage of fentanyl and the test-taking procedure. Given that most home fentanyl tests involve a urine sample, the question parents should know the answer to is: how long will fentanyl show up in urine?

How Long Can Fentanyl Be Detected in Urine?

Young adults who know they are going to be tested have likely already researched this question. A frantic Google search of, “How long is fentanyl in your urine,” will either soothe them (if enough time has passed) or send them into a full-blown panic. In the former case, they will take your test calmly and fearlessly, knowing that they have long since flushed fentanyl out of their systems and will likely test negative. It is a good idea for test administrators to understand this possibility, so that they are not fooled into complacency after one reassuring test result.

So how long is fentanyl detectable in urine? Ultimately, fentanyl urine detection time depends on the person who is abusing the drug. A range of factors influence the speed at which a person can process and metabolize fentanyl and other opioids. These factors include:

  • Their age
  • The strength of their dose
  • How long they have been regularly using fentanyl
  • How frequently they abuse fentanyl
  • Their weight
  • Urine concentration
  • The functionality of their kidney and liver

Individuals who take smaller doses of fentanyl and those in possession of rapid metabolisms (young, healthy people with healthy kidneys and livers) will process fentanyl much more quickly than an older adult who regularly takes high doses. The psychoactive effects of fentanyl only last for several hours, but the above-listed variations can affect how long it takes for fentanyl to stay in a person’s system. However, the most relevant information for parents administering a urine test is how long fentanyl stays in urine.

As a general rule, fentanyl generally remains detectable in urine for 24 to 72 hours after a person has last used fentanyl. As such, it is essential to time a test properly. The most ideal time for testing a young person is when they seem obviously impaired. If they appear distraught, confused, or somehow altered, they are likely either intoxicated or experiencing fentanyl withdrawal. This means they used fentanyl fairly recently, and a test will provide an accurate result.

How is Fentanyl Processed by the Body?

Fentanyl can be taken via a wide variety of routes of administration. Prescription formulations of fentanyl include the fentanyl transdermal patch, which is applied to the skin for several days for a consistent long-lasting dose, the fentanyl lollipop, and fentanyl tablets. The fentanyl lollipop and fentanyl tablets are sublingual formulations that provide a rapid dose. However, individuals who are abusing fentanyl sometimes alter the medication to allow for even faster-acting and potent effects. One such practice involves scraping off the psychoactive gel on the underside of the fentanyl patch. This gel can then be used in a number of ways, such as brewing fentanyl tea, injecting fentanyl directly into the vein, and smoking fentanyl. These methods differ in terms of their risks. They also alter the potency of the drug and the speed of the effects’ onset.

Ultimately, no matter what route of administration a person uses, fentanyl works by activating opioid receptors. Opioid receptors are located throughout a person’s brain, gastrointestinal system, and spinal cord. When opioid receptors activate, pain signals to the brain are blocked. While this phenomenon is responsible for fentanyl’s powerful analgesic effects, it is hardly the only effect. Fentanyl’s side effects also include:

  • Extreme euphoria (the high that draws young people to fentanyl)
  • Gastrointestinal problems, such as nausea, constipation, and stomach cramps
  • Drowsiness
  • Impaired motor function
  • Dizziness
  • Trouble sleeping
  • Increased sweating
  • Headache
  • Loss of appetite
  • Cognitive problems, such as confusion and memory loss
  • Sedation
  • Dilated pupils
  • Fast heart rate
  • Difficulty breathing
  • Unconsciousness

Fentanyl Overdose

Fentanyl can also rapidly lead to an opioid overdose. This occurs when a person takes a higher dose of opioids that their bodies have developed a tolerance for. Given that most young people do not have a long history with opioids, they are particularly susceptible to a fentanyl overdose. Even young people accustomed to taking powerful opioids like heroin rarely have a sufficient tolerance to handle shooting up fentanyl. Unfortunately, fentanyl is frequently added by drug dealers to other drug products, such as heroin, cocaine, and crystal meth. Ssing fentanyl with another depressant like heroin or alcohol increases the risk of overdose, as does using fentanyl with a stimulant. Drug interactions between fentanyl (a depressant) and any stimulant causes the risk of overdosing to soar.

Symptoms of a fentanyl overdose include:

  • Loss of consciousness
  • Stops being responsive to outside stimulus
  • Being awake, but unable to speak
  • Slow, shallow, erratic, or stopped breathing
  • Bluish purple or grayish skin tone
  • Choking or gurgling noises (this is sometimes known as “the death rattle”)
  • Limp body
  • Vomiting
  • Lips and fingernails turn purplish black or blue
  • The heartbeat becomes slow, erratic, or stops entirely

When respiratory depression occurs during a fentanyl overdose, it can be fatal. Parents who suspect their adult child is abusing fentanyl should therefore have naloxone on hand. Naloxone is a drug that can reverse the effects of an opioid overdose. The medication sends them into immediate withdrawal, however. It is prudent for parents to possess naloxone even if their potentially fentanyl-addicted child has not yet tested positive.


What Happens After the “High” Ends?

While fentanyl is initially taken for its pleasurable and euphoric initial effects, these effects tend to wear off after only a few hours. Unfortunately, the effects that follow the opioid “high” are the polar opposite of euphoric. These effects, known as fentanyl withdrawal symptoms, can cause people to seek out fentanyl or other opioids. Fentanyl withdrawal symptoms include:

  • Restlessness or anxiety
  • Runny nose, yawning, and watery eyes
  • Increased susceptibility to physical pain
  • Irritability or mood changes
  • Nausea, vomiting, diarrhea, and stomach cramps
  • Goosebumps, chill, and sweating
  • Tremors and muscle twitching
  • Cramps, aches, and joint pain
  • Blood pressure changes
  • Rapid heart rate
  • Trouble sleeping
  • Suicidal ideation

The fentanyl withdrawal timeline can vary considerably. It generally lasts, however, for approximately one month. The initial phase, lasting a few days, is characterized by extreme cravings. The second phase, acute opioid withdrawal, generally begins after five days or so. This is when fentanyl withdrawal symptoms reach their peak. After another week, these symptoms gradually wane over a few weeks, though some people continue to experience mild opioid withdrawal side effects for months after quitting opioids. Given that fentanyl is detectable in urine for only 24 to 72 hours, it is possible for a young adult to experience adverse results from fentanyl but continue to test negative.


What To Do When Your Child Suffers from a Fentanyl Abuse Problem

If your child has tested positive for fentanyl use, it is clear that they have a fentanyl abuse problem. Unless they are taking fentanyl as prescribed by a physician for severe and chronic pain, there is no “safe” amount of recreational fentanyl abuse. Your child either suffers from a fentanyl addiction or has accidentally used fentanyl while trying to abuse another equally dangerous drug, such as crack cocaine or heroin. If your child has repeatedly tested negative but is exhibiting all of the symptoms of opioid addiction, there is no reason to hesitate to get them help. Given that fentanyl only remains in the urine for a maximum of three days, it might be too late by the time you get a positive test result.

While it is common for young people suffering from addiction to deny their problems or to work hard to manage them on their own, the reality is that addiction cannot be cured through sheer individual willpower. It is, after all, a condition that by definition alters the brain’s ability to make decisions. It may also be tempting for parents to try to help their children themselves. While this may come from a loving place, the truth is that a substance use disorder is a legitimate medical disorder that requires professional help.

A sober living home is generally recommended for young people who have a desire to get sober and rebuild their lives. Sober living homes are residences where young people work together to strengthen their sobriety and make positive and healthy choices. One study on sober living homes found that the social support system that people gain while living in such a residence lowers the likelihood of relapse over the long term. The relationships and connections made in a sober living home can help addicted young people develop hope for their futures, and they can be a source of meaning and joy in lives rendered barren by addiction. Sober living homes are about far more than just maintaining sobriety. They help residents rebuild their lives and take steps toward their goals. For some, this can mean getting involved in academic programs. For others, this means pursuing career goals, perhaps for the first time. No matter how hopeless your child’s addiction now seems, sobriety is possible. There’s no reason for addicted young people — or their worried parents — to suffer alone. Reach out today.

Also Read:

Suboxone in Urine: How Long Does It Stay?

Will Fentanyl Show Up on Your Test Anyway?

It must be emphasized, however, that even if your child has not cheated and they continue to test negative for fentanyl, that does not mean that they are drug-free. It is possible that they are taking a different drug not measured by the particular drug testing kit you used. It is crucial to read the instructions and understand the limitations of the drug kit you’re using to interpret the results properly. It is also important to understand that every drug testing kit can only test for a specific period of time. Your adult child may in fact be using fentanyl despite testing negative. In that case, it is possible that a sufficient period of time passed between their last usage of fentanyl and the test-taking procedure. Given that most home fentanyl tests involve a urine sample, the question parents should know the answer to is: how long will fentanyl show up in urine?


Edited by: David Beasley

David Beasley - Design for Recovery

David Beasley is a certified RADT (Registered Alcohol/Drug Technician). David, moved to California from North Carolina after many failed attempts to get sober.

Medically Reviewed by: Charley Allen

Charley earned his Masters of Clinical Psychology from Antioch University, Los Angeles, and is a California Licensed Marriage and Family Therapist (LMFT).He teaches mindfulness to both adults and children in group setting such as schools, corporate workplaces, and medical treatment facilities.

We Can Help

Design for Recovery - Locations Pages Contact Form

Read More

Addiction & Recovery

Sober Living in Los Angeles - Design for Recovery

About Us

Design for Recovery empowers men struggling with addiction by providing 24/7 support, mentorship, and teaches them how to live healthy, fulfilling lives.

Chat with us on Facebook
relapse prevention

Are you or a loved one struggling with addiction? We can help!

Our advisors are waiting for your call: 424-327-4614

Reach out to us today.

Design For Recovery is committed to helping you or your loved one live a fulfilling life free from alcohol and drug addiction. Below you can find out what to expect when you contact us for help.

Call us at (424) 327-4614 or fill out the form below and we will be in touch with you soon.

Send us a message below and we will reach out to you.
Design for Recovery Contact - Popup