What to Know About Fentanyl Withdrawal

Medically Reviewed by Carol DerSarkissian, MD on June 13, 2024
5 min read

Fentanyl, when used properly, is a treatment for severe pain. Doctors use it to treat pain that doesn’t respond to milder pain killers. It’s generally not recommended for long-term use, though, because it is habit-forming and very difficult to stop using.

This drug is highly addictive and can be dangerous when taken in high doses. There is also a significant amount of illegal fentanyl produced and sold in the United States. Unregulated fentanyl is a leading cause of accidental overdose. 

Quitting fentanyl is difficult under any circumstances, though, due to the extreme withdrawal symptoms it causes.

Fentanyl is a prescription painkiller. It’s a synthetic opioid that pharmaceutical makers developed for treating severe pain. It’s up to 100 times more powerful than morphine. It is both very effective and very addictive.

When used as directed, fentanyl can be part of a legitimate pain management strategy. Doctors might prescribe IV fentanyl to ease pain after surgery. For people with chronic pain, such as pain from cancer, fentanyl patches deliver long-lasting pain relief.

Because the effects of fentanyl are so powerful, you only need small doses to alleviate pain. Taking more than the recommended dose is dangerous. Some people can only tolerate small amounts of the drug. 

A fentanyl overdose amount can be as small as 2 mg of the drug. Overdose can be lethal.

Fentanyl is part of a class of drugs known as opioids. Opioids work by triggering your brain to release chemicals called endorphins. These neurotransmitters are sometimes called feel-good chemicals because they induce a pleasurable sensation, sometimes called euphoria or a high.

Endorphins mute the sensation of pain, which is why opioids are useful as prescription painkillers. They also create a temporary sense of intense well-being or euphoria. That sensation wears off as the drugs leave your system, but the desire to reproduce that feeling may linger. If you then seek out more opioids, you can kick off a cycle of drug use that is very hard to break.

Over time, you can become dependent on opioids like fentanyl to give you a sense of well-being. The drive to get more of the drug is the beginning of addiction. Eventually, those feelings may be overpowering. 

In addition, going without the drugs triggers physical discomfort that intensifies the desire to take opioids and stop the negative symptoms.

Many people who develop fentanyl dependence do so after a doctor prescribes it for medical reasons. Taking any opioid for more than a couple of weeks can lead to addiction. Some doctors are hesitant to prescribe opioids for long-term pain management because of the risk of addiction.

A significant danger of opioid addiction is the need to increase the amount you’re taking. As your body gets used to the drugs, you need higher doses to achieve the desired effects. Taking large doses of any drug comes with a risk of overdose, which can cause death.

If you have developed a dependence on fentanyl or other opioids, your body will negatively react when you stop taking the medicine. The fentanyl withdrawal timeline begins quickly. Withdrawal symptoms can start as soon as 12 to 30 hours after your last dose.

Symptoms include:

  • Intense cravings for fentanyl
  • Chills or goosebumps
  • Diarrhea
  • Irritability
  • Nausea or vomiting
  • Pain (muscle cramps, bone pain)
  • Runny nose and yawning
  • Restless sleep or trouble sleeping
  • Sweating
  • Stomach cramps
  • Weakness

The fentanyl withdrawal symptoms usually last for several days. Your body will adjust, and you will physically feel better. You may notice that you continue to feel slightly off for several weeks after stopping opioids. The psychological effects of addiction will linger.

If you have taken fentanyl for more than two weeks, you should work with your doctor on a plan to stop taking it. Opioid withdrawal symptoms can be severe, and most people benefit from medical supervision while detoxing. You may need additional medications to mitigate the effects of withdrawal. 


In some cases, you can slowly reduce the amount of fentanyl you take until you no longer need it. This process is called tapering. Your doctor will help you develop a schedule to wean yourself off your medication over weeks or months.

While you are tapering, your doctor will monitor your health. You may need regular visits to check your vital signs and track symptoms. You may need to give blood samples to check the medication levels in your system.

Your doctor may suggest that you see a mental health professional to help you manage any emotional distress you feel about the withdrawal process. Behavioral changes can also help with physical and emotional symptoms. 

Coping mechanisms might include:

  • Getting enough to eat and drink
  • Getting moderate exercise
  • Relaxation techniques such as stretching, breathing experiences, or meditation
  • Positive social interactions
  • Pleasant recreational activities to occupy your time and attention 

If you take fentanyl for a painful health condition, your doctor can also help you with a new pain management strategy. Controlling your pain will help you resist the temptation to take fentanyl for your health condition.

Medication-Assisted Treatment

Your doctor might suggest that you use a medication-assisted treatment program to discontinue fentanyl use. This treatment uses a different opioid, usually methadone or buprenorphine, to replace fentanyl. Methadone and buprenorphine address the physical cravings for opioids without causing the euphoric effects of fentanyl.

This type of treatment program requires medical supervision. Your doctor will determine your dosage, how often you take the replacement drugs, and how long you will be on the program. You may be able to slowly taper off methadone or buprenorphine. The treatment can also be a long-term approach to managing opioid addiction.

If you are addicted to fentanyl, the withdrawal symptoms may drive you to purchase it illegally. This is very dangerous, though, because illicitly-produced fentanyl is not regulated. There is no way to be sure of the ingredients of the dose. You may get a dose that is significantly higher than what is safe. That can lead to overdose, which may cause death. 

Illicit fentanyl is one of the leading causes of drug overdoses in the United States.

If you have withdrawal symptoms from trying to quit fentanyl, get medical attention right away. A doctor can help you manage withdrawal symptoms without resorting to illegal opioids.

If you suspect you or someone you know has overdosed on fentanyl, call 911 immediately.