Updated: Dec 15, 2022
Fentanyl stays in the body between 5 and 48 hours on a blood test, 24 to 72 hours on a urine test, and up to 3 months on a hair test, with the exact window set by dose, route and how often a person uses.
Overdose death rates involving synthetic opioids, including fentanyl and fentanyl analogs, rose by over 56% from 2019 to 2020, according to the Centers for Disease Control and Prevention. More than 56,000 people died from overdoses involving synthetic opioids in 2020, and synthetic opioids are now the drugs most involved in drug overdose deaths in the United States.
What Is Fentanyl?
Fentanyl is a synthetic opioid approved for treating chronic pain and severe pain, prescribed after surgery and for advanced cancer pain. The CDC records fentanyl as approximately 50 times stronger than heroin and 100 times stronger than morphine as an analgesic. Fentanyl is a Schedule II narcotic under the United States Controlled Substances Act of 1970.
Some fentanyl is diverted from medical supply through theft, fraudulent prescriptions and illicit distribution. Much of the street supply is manufactured illegally.
Illicitly made fentanyl (IMF) circulates on the drug market mixed with drugs including heroin, cocaine, methamphetamine, and MDMA. There are 4 illegal forms:
- powder
- blotter paper
- eye droppers and nasal sprays
- pills that mimic other prescription opioids
The DEA records a re-emergence of trafficking, distribution and use of illicitly produced fentanyl and fentanyl analogues, with a matching increase in overdose.
Many illicit drugs contain deadly doses of fentanyl, because it takes very little fentanyl to produce a high, which makes it a cheap additive. That additive leads people to take stronger opioids than their bodies are used to, which raises overdose risk.
How Does Fentanyl Work?
Fentanyl activates opioid receptors and produces 4 effects, in common with other opioid analgesics such as morphine:
- relaxation
- euphoria
- pain relief
- sedation
Fentanyl also produces an intense short-term high, slowed respiration and reduced blood pressure.
Prescribed fentanyl is administered as a shot, as a patch placed on the skin, or as lozenges used like cough drops. Medical professionals consider fentanyl effective for monitored pain management, and it carries a risk of misuse even when taken as directed.
How Does Fentanyl Change the Brain?
Fentanyl binds to opioid receptors that govern pain and emotion, and that binding increases dopamine release from nerve cells in the brain’s reward center. The increased dopamine release produces the feeling of euphoria that follows fentanyl and other opioids.
How Does Fentanyl Change the Body?
Fentanyl suppresses central nervous system functions, and people who use fentanyl experience changes to heart rate, body temperature and breathing rate. Extended fentanyl use produces structural changes in the brain and reduces the brain’s capacity to produce dopamine on its own. That reduced capacity drives fentanyl dependence and addiction.
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How Long Does Fentanyl Stay In Your System?
Fentanyl appears on a urine test between 24 and 72 hours after last use, on a blood test between 5 and 48 hours depending on the dose, and on a hair test up to 3 months after last use.
There are 6 factors that set how long fentanyl stays in a person’s body:
- age
- gender
- weight
- height
- lifestyle habits
- health and medical conditions
A person who uses fentanyl occasionally metabolizes it faster than someone who takes high doses or uses regularly. The outer detection range reaches 26 days after last use.
How Long Does Fentanyl Stay In Your System When Taken Orally?
Fentanyl taken orally stays in the body for 72 hours on a blood test and up to 90 days on a hair test. People take fentanyl by mouth as a lozenge, designed to dissolve slowly and enter the body over a regulated period. Chewing the lozenge releases the whole dose at once.
Chewing fentanyl creates prolonged contact with enzymes in the mouth, which releases more of the substance into the body and raises the risk of side effects. The drug stays in the system for at least 72 hours after use. Some people chew fentanyl patches, which raises the chance of accidental overdose, digestive blockage, and choking on the patch.
How Long Does Fentanyl Stay In Your System When Smoked?
Smoked fentanyl reaches the brain faster than any other route, which makes the dose harder to control and shortens the time before respiratory distress begins. People crush fentanyl tablets or buy fentanyl powder illegally to smoke it for a faster and stronger high. Fentanyl powder sold on the street contains other drugs, including crack cocaine.
Slowed breathing is a common effect of fentanyl, as with most opioids. Smoking fentanyl makes it harder for oxygen to reach the lungs. Respiratory distress from opioid use is fatal without emergency treatment.
What Are the Signs of a Fentanyl Overdose?
A fentanyl overdose produces chest pain, slowed or shallow breathing, bluish lips and complexion, seizure, and loss of consciousness, and it needs emergency medical care immediately. Treatment for opioid use disorder lowers overdose risk.
There are 5 overdose symptoms that need an ambulance, whether the overdose is intentional or unintentional:
- chest pain
- slowed or shallow breathing
- bluish-colored lips and complexion
- seizure
- loss of consciousness
The DEA records 4 further overdose effects:
- stupor
- changes in pupillary size
- cold and clammy skin
- respiratory failure leading to death
The presence of any three of pinpoint pupils, loss of consciousness and respiratory depression indicates opioid poisoning.
Where you suspect that you or someone you know has overdosed, call 911 or go to the nearest medical facility.
Can You Stop Using Fentanyl Cold Turkey?
Stopping fentanyl abruptly produces withdrawal symptoms that range from irritability and insomnia to vomiting, raised heart rate and depression, and medical supervision keeps that process safe. Withdrawal covers the physical and mental symptoms that follow stopping or reducing intake of a drug a person depends on. Withdrawal symptoms vary by the drug and by the severity of dependence.
A person who has used fentanyl regularly and developed physical dependence experiences withdrawal symptoms on stopping. The intensity varies by the length and amount of use.
There are 9 typical fentanyl withdrawal symptoms:
- 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
- nausea and vomiting
- increased heart rate and blood pressure
- muscle and bone aches
- depression
How Do You Safely Detox From Fentanyl?
Medically supervised detox is the safest route off fentanyl, because withdrawal symptoms begin within 12 hours of last use and continue for up to a week, with the first three days the most severe. Detoxification is the first step in treatment for people with fentanyl addiction or substance use disorder. The Alcohol and Drug Foundation records the first three days as the most difficult.
Withdrawal under medical supervision, or medically supervised detox, protects a person’s safety during this stage of recovery. Medical detox manages the intense physical effects of opioid withdrawal.
To learn more about medical detox programs for fentanyl dependence or substance use disorder, contact our admissions team. Our licensed team answers questions and provides information about the treatment program.
Drug Fact Sheet, Fentanyl: https://www.dea.gov/sites/default/files/2020-06/Fentanyl-2020_0.pdf
United States Drug Enforcement Administration, Fentanyl: https://www.dea.gov/factsheets/fentanyl
National Institute on Drug Abuse (NIDA), Fentanyl DrugFacts: https://nida.nih.gov/publications/drugfacts/fentanyl
Clinical Guidelines for Withdrawal Management and Treatment of Drug Dependence in Closed Settings. Geneva: World Health Organization; 2009. 4, Withdrawal Management. Available from: https://www.ncbi.nlm.nih.gov/books/NBK310652/