How Long Does Fentanyl Stay In Your System?

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Updated: Dec 15, 2022

Overdose death rates involving synthetic opioids, like fentanyl – and fentanyl analogs – have increased by over 56% from 2019 to 2020 (Centers for Disease Control and Prevention (CDC)). More than 56,000 people died from overdoses involving synthetic opioids in 2020 alone and synthetic opioids are now the most common drugs involved in drug overdose deaths in the United States.

Most recently, cases of fentanyl-related harm, overdose, and death in the U.S. have been linked to illegally made fentanyl. But what is this powerful prescription opioid that has risen in popularity over the past several years?

What Is Fentanyl?

Fentanyl is a synthetic opioid, pharmaceutically approved for treating chronic pain and severe pain; it is often prescribed after surgery or to those with advanced cancer pain.

According to the CDC, this synthetic opioid is approximately 50 times stronger than heroin and 100 times stronger than morphine as an analgesic. It is a Schedule II narcotic under the United States Controlled Substances Act of 1970. Some fentanyl is diverted from medical purposes (via theft, fraudulent prescriptions, and illicit distribution) for illicit use, however, much of the street supply is manufactured illegally.

Illicitly made fentanyl (IMF) is often found on the drug market and is commonly mixed with drugs like heroin, cocaine, methamphetamine, and MDMA. It can be found illegally in the following forms:

  • powder
  • dropped on blotter paper
  • in eye droppers and nasal sprays
  • pills that mimic other prescription opioids 

More recently, according to the DEA, there has been a re-emergence of trafficking, distribution, and abuse of illicitly produced fentanyl and fentanyl analogues with an associated dramatic increase in overdose.

Many illicit drugs may contain deadly doses of fentanyl because it takes very little to produce a high with fentanyl, making it a cheaper option. This cheap but dangerous additive might cause individuals to take stronger opioids than their bodies are used to and can be more likely to overdose as a result.

How Does Fentanyl Work?

Fentanyl, similar to other commonly used opioid analgesics (e.g., morphine), produces effects such as the following:

  • relaxation
  • euphoria
  • pain relief
  • and sedation

It is also known to produce an intense short-term high, slowed respiration, and reduced blood pressure. 

When prescribed, fentanyl may be administered as a shot, given as a patch to place on the skin, or as lozenges, to be used like cough drops. Although medical professionals consider fentanyl to be effective in prescribed pain management when monitored, it still has the potential for abuse even when taken appropriately.

Fentanyl And The Brain

Fentanyl binds to and activates certain opioid receptors in the brain that affect pain and emotions. Through this interaction, fentanyl increases the release of another chemical, dopamine, from certain nerve cells in our brain’s reward center. This increased release of dopamine is responsible for the subsequent feeling of euphoria from fentanyl, and other opioids. 

Fentanyl and The Body

Fentanyl may also suppress some central nervous system functions and those who use fentanyl may experience changes to their heart rate, body temperature, and breathing rate. Extended use of fentanyl may also cause serious structural changes in the brain and cause the brain to have difficulty producing dopamine on its own. This inability for the brain to produce dopamine independently may lead to fentanyl dependence and even addiction.  

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How Long Does Fentanyl Stay In Your System?

Several factors can affect how long fentanyl stays in a person’s body. Factors that affect how someone can metabolize the drugs include their:

  • age
  • gender
  • weight
  • height
  • lifestyle habits
  • health/medical conditions

A person who uses drugs occasionally may be able to metabolize the drug faster than someone who consumes high doses of the drug or regularly engages in drug use. Fentanyl can sometimes be detected for up to 26 days after the last use.

Additionally, there are a number of drug tests used to detect fentanyl including blood, urine, and hair tests. Fentanyl will often appear on a urine test between 24 and 72 hours after the last use. In blood tests, it may be detected between 5 and 48 hours after the last use, depending on the dose, and in hair tests, it may be detected up to 3 months after the last use.

How Long Does Fentanyl Stay In Your System When Taken Orally?

Fentanyl may be consumed by mouth, as a lozenge. It is intended to slowly dissolve in the mouth to enter into an individual’s body in a regulated time. But, chewing the lozenge allows for the drug to be absorbed into the system all at once. Fentanyl can stay in your body if you eat it for 72 hours on a blood test and up to 90 days for hair tests.

Chewing fentanyl creates prolonged contact with enzymes in the mouth. Using this method may release more of the substance into your body, leading to increased risks of side effects. It is possible the drug will stay in your system for at least 72 hours after use. Additionally, some individuals abuse Fentanyl patches by chewing them. Eating fentanyl patches increases the chance of an accidental overdose, getting blocked in the digestive system, or choking on the patch.

How Long Does Fentanyl Stay In Your System When Smoked?

For a faster and stronger high, individuals may crush fentanyl tablets or illegally purchase fentanyl powder to smoke. This method becomes more dangerous as smoking reaches the brain quicker and the inability to control the dosage. Additionally, fentanyl powder sold on the street commonly contains other drugs such as crack cocaine. 

Slower breathing rates are a common side effect of fentanyl, like most opioids. When this substance is smoked, it makes it more difficult for oxygen to reach the lungs causing respiratory distress and could result in death. 

Fentanyl Overdose Effects

As mentioned, Fentanyl is associated with an alarming overdose rate. By seeking treatment for opioid addiction you can prevent a potential fentanyl overdose. If you or a loved one is experiencing any of the following symptoms of overdose, whether intentionally or unintentionally, call an ambulance immediately:

  • Chest pain
  • Slowed or shallow breathing
  • Bluish-colored lips and complexion
  • Seizure
  • Coma or loss of consciousness
  • Passing out

The DEA notes that fentanyl overdose may also result in the following:

  • stupor
  • changes in pupillary size
  • cold and clammy skin
  • respiratory failure leading to death 

Specifically, the presence of any three of these symptoms (i.e. pinpoint pupils, loss of consciousness, respiratory depression) is strongly suggestive of opioid poisoning.

If you suspect that you or your loved one has overdosed, please contact 911 or visit your nearest medical facility.

Fentanyl Withdrawal Symptoms -Can I Stop Using Fentanyl Cold Turkey?

Withdrawal refers to the physical and mental symptoms that occur as a result of stopping or reducing intake of the drug of dependence. Withdrawal symptoms vary according to the drug of dependence and severity of dependence.

If you’ve used fentanyl regularly and have developed a considerable physical dependence, you will likely experience withdrawal symptoms. The intensity of the withdrawal symptoms will vary from person to person depending on the length and amount used. 

Typical symptoms of fentanyl withdrawal include:

  • irritability
  • insomnia or difficulty sleeping
  • loss of appetite
  • “goose bumps” or small bumps on the skin from chills
  • chills and bouts of excessive sweating or feeling flushed
  • vomiting and nausea
  • increased heart rate and blood pressure
  • muscle and bone aches 
  • depression

How to Safely Detox from Fentanyl

For many people struggling with fentanyl addiction or substance use disorders, detoxification is the first step in treatment. It may be difficult to safely detox from fentanyl when one’s body has gotten used to functioning with it. Fentanyl withdrawal symptoms may begin within the first 12 hours after the last use and may last for up to a week. The most difficult is the first three days, according to the Alcohol and Drug Foundation. Dealing with these symptoms on one’s own can be extremely difficult and dangerous. 

Withdrawal under the supervision of medical professionals, or medically supervised detox, is the best way to ensure one’s safety during this stage of recovery. Medical detox is particularly necessary in order to help manage the intense physical effects of withdrawal. Opioids in particular can cause intense withdrawal symptoms.

In general, the best way to safely detox from fentanyl addiction or dependence is by entering medical detox treatment.   

If you or a loved one would like to learn more about medical detox programs to help overcome fentanyl dependence or substance use disorder, our licensed team can help you start your road to recovery. Our admissions team is available to answer your questions and provide you with additional information regarding our treatment program to help you get your life back today.

Drug Face Skeet–Fentanyl:

United States Drug Enforcement Administration–Fentanyl:

National Institute on Drug Abuse (NIDA)–Fentanyl DrugFacts

Clinical Guidelines for Withdrawal Management and Treatment of Drug Dependence in Closed Settings. Geneva: World Health Organization; 2009. 4, Withdrawal Management. Available from:

NIDA. 2021, June 1. Fentanyl DrugFacts. Retrieved from