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Duration of fentanyl detection in the body: How long does it stay?

Reading time: 10 mins
syringe and needle

Fentanyl is a pain reliever that is made in a lab. It is in a group of drugs called opioids. It is useful for treating severe pain such as post-surgical pain and medical disorders due to its great potency and early onset of action. 

Fentanyl can be used by most adults. In particular, patients with cancer, individuals experiencing post-surgical pain, and terminally ill patients may use fentanyl for pain management. Fentanyl is used as part of general anesthesia, for managing breakthrough cancer pain, and for treating moderate-to-severe chronic pain. 

The common side effects of fentanyl include lightheadedness or dizziness, drowsiness, constipation, euphoria, nausea and vomiting, shallow breathing, reduced appetite, and confusion. 

Fentanyl is commonly detectable in urine between 24-72 hours after last usage. Hair tests can identify the drug for up to three months after usage, while blood tests can detect it between five and 48 hours after use, depending on the amount.

What is fentanyl?

Fentanyl is a highly strong synthetic opioid medicine that is often used for pain management, particularly in cases of severe pain or when other pain reduction approaches have failed. It is frequently delivered via transdermal patches, lozenges, nasal sprays, and injectable formulations.

Fentanyl efficiently lessens pain perception by attaching to opioid receptors in the brain and spinal cord. The fact that fentanyl is substantially stronger than other opioids like morphine or oxycodone raises the possibility of overdose and necessitates careful dosage control under a doctor’s supervision.

What class of drugs does fentanyl belong to?

Fentanyl belongs to the class of drugs known as narcotic (opiate) analgesics, also known as pain medicines. Narcotic analgesics are painkillers that are given by prescription to treat moderate to severe pain. They are most often given to relieve short-term, severe pain caused by a medical disease or pain that comes right after surgery, according to an article on fentanyl (injection route) published in Mayo Clinic

Fentanyl is not made from opium but rather is a synthetic opioid. When compared to other opioids like morphine or oxycodone, its potency stands out. Medical professionals frequently prescribe fentanyl for patients experiencing intense pain, such as that experienced after surgery or as a result of cancer treatment.

Who can take fentanyl?

Fentanyl is typically prescribed by healthcare professionals to individuals who are experiencing severe pain that is not effectively managed by other, less potent pain medications. People who can take fentanyl are listed below. 

  • Most adults: The majority of adult individuals can use fentanyl, according to an article titled, “Who can and cannot use fentanyl” from the National Health Service (NHS).
  • Patients with cancer: An article on fentanyl published in MedlinePlus states that fentanyl is prescribed to patients with cancer who have developed a tolerance to other narcotic (opiate) pain drugs and are receiving regular dosing of those medications. Patients must be at least 18 years old (or 16 years old if using Actiq brand lozenges) to receive fentanyl.
  • Individuals experiencing post-surgical pain: Fentanyl might be prescribed to individuals who have undergone surgery and are experiencing significant pain during the recovery process.
  • Terminally ill patients: Children with terminal cancer or adults who are terminally ill often use transdermal fentanyl patches because they need daily, round-the-clock pain medicine.

How is fentanyl typically used?

empty pill bottles and pills scattered on the table

Fentanyl is typically used as a transdermal patch, as lozenges, nasal spray, in injectable form, or sublingual tablets. One of the most common methods of using fentanyl is through transdermal patches. These patches are applied to the skin and release the medication slowly over a specified period, usually 24 to 72 hours. They are often used for chronic pain management.

Patients can also chew on lozenges or lollipops containing fentanyl in order for the medication to be absorbed through the mucous membranes in the mouth. This is a common treatment for breakthrough pain in cancer patients.

According to an article on fentanyl (nasal route) published in Mayo Clinic, the nasal spray form of fentanyl can also be used to treat breakthrough cancer pain. Fentanyl also comes in injectable forms that can be given by medical workers in places like hospitals and surgical centers. It could be used during surgery or to treat pain in the short term.

Sublingual pills of fentanyl are taken orally and dissolved under the tongue. Patients on continuous opioid therapy utilize this technique to treat sudden, severe pain that has not responded to the medication.

What are some medical uses of fentanyl?

The medical uses of fentanyl include as part of general anesthesia, managing breakthrough cancer pain, and treating moderate-to-severe chronic pain. 

Fentanyl is typically used as part of general anesthesia in many procedures. According to an article titled, “Can Fentanyl Be Used in Anesthesia?” from Guardian Recovery Network, depending on the treatment and level of sedation needed, fentanyl can be given as anesthesia through an intravenous line, a muscle injection, an epidural line, or by injecting it into the spine.

Fentanyl can also be used to manage sudden and severe episodes of pain that occur in patients who have cancer and who are already receiving opioid medication for persistent pain. Finally, the opioid medication is indicated for the management of persistent, moderate-to-severe chronic pain that necessitates uninterrupted, 24-hour opioid therapy.

What are the side effects of fentanyl?

Fentanyl, like other opioids, can cause a range of side effects, some of which can be serious. The most common side effects of fentanyl are listed below.

  • Lightheadedness or dizziness: According to drug information on fentanyl published in GoodRx, fentanyl can cause very low blood pressure, which can happen when you stand up after sitting or lying down. This can make you feel lightheaded or dizzy.
  • Drowsiness: Fentanyl causes drowsiness primarily by its effects on the central nervous system. Because it is a strong opioid, fentanyl causes a variety of physiological and psychological effects, including drowsiness, by acting on particular receptors in the brain and spinal cord.
  • Constipation: Opioids slow down digestion in a number of distinct ways. For instance, a 2022 article on how to treat opioid induced constipation from Verywell Health states that opioids can produce gastroparesis in the stomach, which means that the stomach takes longer than it should to empty because the muscles are not functioning properly.
  • Euphoria: Opioids are depressants that cause sedation or euphoria by slowing down biological activities. Opioid receptors are found throughout the neurological system. When these receptors are triggered, a transient feeling of euphoria, or a “high,” is produced, as well as a blockage of certain substances in the body that cause us to feel pain, as stated on an article titled, “Fentanyl and Other Overdose Risks” from the Mississippi State Department of Health.
  • Nausea and vomiting: A 2012 article on opioid-induced nausea and vomiting published in the Annals of Palliative Medicine states that the mechanisms underlying nausea and vomiting brought on by opioids are highly complex. Opioid-induced nausea and vomiting could be brought on by a variety of opioid side effects, such as (I) greater sensitivity of the vestibular system (which could cause vertigo that gets worse with movement), (II) direct impacts on the chemoreceptor trigger zone, and (III) delayed emptying of the stomach (which could cause early fullness and bloating that gets worse after eating).
  • Shallow breathing: Fentanyl binds to opioid receptors in the brain, including those present in the respiratory centers. When these receptors are activated, it can interfere with the normal signaling that regulates breathing.
  • Reduced appetite: Fentanyl can cause reduced appetite as a side effect due to its impact on the central nervous system and certain neurotransmitters that regulate appetite and feeding behavior.
  • Confusion: When using an opioid for the first time, confusion is a side effect that may be experienced during the first few days to weeks, according to an article on opioid-induced neurotoxicity from Pharmacists Manitoba. A 2007 article by Romayne Gallagher, MD CCFP published in the Canadian Family Physician adds that the symptoms of opioid-induced neurotoxicity span from moderate confusion or drowsiness to delirium, hallucinations, and seizures due to the syndrome’s complex nature.

What are the methods for detecting fentanyl in your body?

There are several methods for detecting fentanyl in your body, depending on the purpose, the sample type, and the sensitivity of the test. The common methods for detecting fentanyl in your body are listed below. 

  • Urine test: Urine drug tests are commonly used to detect the presence of fentanyl and its metabolites in the body. Depending on the dosage, frequency of use, and individual metabolism, fentanyl can be found in urine for a while after administration.
  • Blood test: This is a more precise and reliable way to determine the presence of fentanyl and its metabolites in your body. Within a few hours of the last dose, it can detect fentanyl use. It is more expensive and invasive than a urine test, though. To conduct the test, specialized tools and qualified personnel might be needed.
  • Saliva test: Saliva tests are also often used for immediate drug use detection and in workplace drug testing or roadside testing scenarios.
  • Hair test: Hair follicle tests can detect fentanyl for a longer period than urine or blood tests. A hair sample is collected, and the presence of fentanyl is analyzed in the hair strands. However, it is not very useful for detecting recent or occasional use of fentanyl. It may also be influenced by factors such as hair color, hair growth rate, hair treatment, and environmental contamination.

How long does fentanyl stay in your body?

syringe and needle

Fentanyl stays in the body for a duration ranging from 24 to 72 hours, according to a 2021 article titled, “Fentanyl: What You Need to Know” from WebMD. It’s important to note, however, that individual variations in metabolism and other factors can influence how long fentanyl stays in your body. 

How long does fentanyl last in urine?

Fentanyl generally lasts in the urine for 24 to 72 hours, or one to three days after use. Still, it’s important to keep in mind that the duration at which fentanyl and its metabolites can be detected in urine can vary based on several factors, including the dose taken, the individual’s metabolism, and the sensitivity of the testing method.

Can a urine drug test be used to identify fentanyl?

Yes, a urine drug test can be used to identify fentanyl and its metabolites in the body. A urine drug test can be performed by using a quick and inexpensive method called immunoassay, which uses antibodies to detect the presence of fentanyl or its metabolites in your urine.

However, according to an article titled, “False Positives for the Presence of Fentanyl” from Guardian Recovery Network, environmental factors or chemicals that can interfere with test results can contaminate urine drug test samples. For example, if the person taking the test was exposed to fentanyl in the environment or touched a fentanyl-contaminated substance, a false positive result could occur.

How long can fentanyl be detected in a blood test?

Fentanyl can be detected in a blood test between five and 48 hours or up to two days after the last use. Because of its rapid onset of action and relatively short duration of effects, fentanyl’s presence in blood can be detected within a few hours after administration. 

However, the exact detection window can vary among individuals. Factors such as the specific formulation of fentanyl, the amount taken, and individual factors can influence how long fentanyl remains detectable in the bloodstream.

What is the approximate time frame for detecting fentanyl in saliva?

The approximate time frame for detecting fentanyl in saliva is one to three days, according to a 2023 article titled, “How Long Does Fentanyl Stay in Your System?” from The Recovery Village. 

However, certain contradictory research findings exist. For instance, according to a 1993 analysis on the duration of fentanyl and its metabolites in urine and saliva published in Anesthesia & Analgesia, saliva testing is not deemed reliable because it cannot consistently detect fentanyl or its metabolites.

How long can fentanyl be detected in a hair follicle drug test?

needles, pills and empty pill bottles.

Fentanyl can be detected in a hair follicle drug test for up to 90 days or three months after the last dose. Fentanyl can be detected in a hair follicle drug test for a longer period compared to other testing methods such as urine or blood tests. 

Hair follicle tests can provide information about drug use over an extended period of time, usually several months or even longer, depending on the length of the hair sample analyzed. It may also depend on the dose and frequency of use of fentanyl, as well as your hair color, growth rate, and treatment.

What are the factors that affect fentanyl detection times?

Factors that affect fentanyl detection times include dose and frequency of fentanyl use, method of administration, metabolism, age, and drug interactions.

The amount of fentanyl taken and how often it is used can impact how long it remains detectable. Higher doses or frequent use may lead to longer detection times.

The way fentanyl is administered can also affect its detection window. Different formulations, such as transdermal patches, short-acting forms, or injectable forms, may have different detection times. For instance, using transdermal fentanyl, which has a relatively extended half-life (13-22 hours) compared to other fentanyl formulations, may increase the amount of time the drug is detectable in the body.

Individual metabolism varies as well, and some people may metabolize and eliminate fentanyl faster or slower than others, which can affect the detection time of fentanyl in their bodies. In connection with this, metabolism and drug clearance can change with age. Younger individuals may process drugs at a faster rate than older individuals.

Finally, certain medications can influence fentanyl metabolism and excretion, thus changing the detection window. For instance, according to a 2022 article titled, “How Long Does Fentanyl Stay In Your System?” from The Recovery Village at Palmer Lake states that medications that affect CYP3A4, the major enzyme responsible for fentanyl breakdown, may cause the drug to last shorter or longer than planned.

Where can you purchase fentanyl?

There is currently no way to electronically prescribe fentanyl or have it “called in” to your local pharmacy. Many drugstores don’t keep this medication in stock, but they can get it for you if you ask, as stated in a 2023 article about Fentanyl Citrate (Actiq®) from OncoLink

It is worth noting that fentanyl is a Schedule II controlled substance, which means it has a high risk of physical and psychological dependence, as well as use disorder and misuse. 

Refills are also not permitted for fentanyl, as Schedule II medications are subject to the strictest rules when compared to other prescription drugs, according to the continuing education activity on the benefits and risks of the prescription of controlled substances published in StatPearls.

Does fentanyl require a doctor’s prescription?

Yes, fentanyl requires a doctor’s prescription to obtain and use legally. Fentanyl is a synthetic opioid drug that is up to 100 times stronger than morphine, heroin, or oxycodone and is used to treat moderate to severe pain, according to an article on fentanyl published in

An article about fentanyl published in MedlinePlus adds that only doctors with extensive training in relieving cancer patients’ pain should prescribe fentanyl. The Controlled Substances Act (CSA) also classifies fentanyl as a schedule 2 substance because it can be misused, abused, and lead to fatal overdoses.

Why is fentanyl considered highly addictive compared to other drugs?

Fentanyl is considered highly addictive compared to other drugs due to its potent opioid properties, rapid onset of action, and the way it affects the brain’s reward and pleasure centers. 

As an analgesic, it is approximately 100 times stronger than morphine and 50 times stronger than heroin, according to a fact sheet on fentanyl from the United States Drug Enforcement Administration. This means that a very small amount can produce a powerful effect. Fentanyl also reaches the brain very quickly, especially when it is snorted, smoked, injected, or absorbed through the skin or mucous membranes.

Like other opioids, fentanyl stimulates the reward circuit of the brain and causes the release of dopamine. The neurotransmitter dopamine has been linked to both motivation and satisfaction. The strong euphoria and general sense of well-being that may result from a dopamine spike eventually lead to drug addiction.

Is fentanyl illegal?

needle, pills and syringe.

No, fentanyl itself is not illegal when it is used and prescribed for legitimate medical purposes by a licensed healthcare provider. However, fentanyl can also be illicitly produced and sold by drug traffickers, who often mix it with other drugs such as heroin or cocaine, or make counterfeit pills that look like prescription opioids.

Illicit fentanyl is much more dangerous than pharmaceutical fentanyl, because it is often more potent, varies in purity and dosage, and may contain unknown additives or contaminants. In fact, fentanyl and its other forms have been responsible for the majority of drug overdose deaths in the United States since 2018, accounting for over 71,238 deaths in 2021, according to data from CDC’s National Center for Health Statistics

Illicit fentanyl is illegal under federal and state laws, and anyone who possesses, distributes, or manufactures it can face severe penalties.