Fentanyl Withdrawal: Signs, Timeline, And Treatment

Medically Reviewed by Johnelle Smith, M.D. on March 17, 2023

Fentanyl is more powerful than other opioid drugs and can produce more powerful withdrawal symptoms as a result. Withdrawal symptoms include both physical and mental health difficulties, and they may last for several weeks.

Fentanyl Withdrawal

Fentanyl addiction is a complicated condition due to difficult opioid withdrawal symptoms.

For people with opioid use disorder, stopping fentanyl can produce uncomfortable physical, mental, and emotional symptoms. In some cases, these symptoms can be dangerous.

Fortunately, fentanyl addiction treatment programs offer medical detox and medication-assisted treatment to help people deal with opioid withdrawal syndrome safely.

What Is Fentanyl?

Fentanyl, similar to oxycodone and morphine, is an opioid drug that is sometimes prescribed for severe pain relief.

However, as fentanyl is stronger than other opioids, it is usually only prescribed for post-surgery pain, cancer pain, and pain that has become resistant to other medications.

Although fentanyl is only legally available with a prescription, imitation fentanyl is often made in illegal drug labs.

Street fentanyl is cheap and easy to produce, so it often ends up in other street drugs to improve profit margins for drug dealers.

Synthetic Vs. Natural Opioids

Fentanyl is a synthetic opioid, which means that it is not derived from natural substances. In contrast, natural opioids (opiates) are derived from the opium poppy.

Both types of opioids work by attaching to the brain’s opioid receptors. This process blocks pain signals and can produce euphoria.

It is important to note that while opiates are nature-derived substances, this does not mean that they can be used without risk.

Natural opiates, like synthetic opioids, can lead to opioid dependence and other dangerous side effects.

However, synthetic opioids such as fentanyl are usually much stronger than opiates. In fact, fentanyl is at least 50 times stronger than morphine.

Get Started On The Road To Recovery.

Get Confidential Help 24/7. Call Today!

(844) 616-3400

The Side Effects Of Fentanyl Use

The side effects of fentanyl are similar to the side effects of other opioid drugs, but the effects may be stronger due to the potency of the drug.

Physical Side Effects

While fentanyl is effective for pain relief, it can also produce adverse physical effects.

Some physical side effects of fentanyl include:

  • sedation or difficulty sleeping
  • drowsiness
  • dizziness
  • nausea and vomiting
  • feeling cold
  • difficulty urinating
  • constipation
  • changes in blood pressure and heart rate
  • respiratory depression (slowed or stopped breathing)

Psychological Side Effects

In the short term, fentanyl can produce a euphoric high. However, it can also have a negative impact on mental health, both in the short term and the long term.

Some mental and emotional side effects of fentanyl include:

  • confusion
  • anxiety
  • hallucinations
  • false sense of wellbeing
  • depression
  • agitation

Overdose Risks

Due to its potency, the risk of fentanyl overdose is high. Patients should work closely with their healthcare providers to mitigate these risks if they are prescribed fentanyl.

Annual Fentanyl Overdose Rates

According to a fentanyl awareness campaign from the U.S. Drug Enforcement Administration (DEA), 67% of overdose deaths in 2021 involved synthetic opioids, including fentanyl.

One reason for this high percentage comes from the fact that fentanyl is found in many street drugs. Therefore, it is often consumed accidentally.

A life-threatening amount of fentanyl is as low as two milligrams, and many people unknowingly consume more fentanyl than their bodies can handle.

Signs Of Overdose

The signs of fentanyl overdose are similar to the signs of opioid overdose in general.

These signs are:

  • pinpointed pupils
  • slowed heart rate
  • unresponsiveness
  • extreme drowsiness
  • seizures
  • coma
  • slowed breathing or difficulty breathing

Responding To An Overdose

If you or a loved one deal with opioid addiction, ask a doctor or pharmacist about carrying naloxone.

Naloxone is a prescription opioid agonist that can reverse the effects of an opioid overdose if administered quickly.

Call 911 immediately, even if naloxone awakens the person who has overdosed, and follow the instructions of emergency personnel.

Fentanyl Withdrawal

Fentanyl withdrawal is often the most difficult part of recovering from fentanyl addiction.

Many people would like to stop using fentanyl but keep taking the drug to relieve intense cravings and other fentanyl withdrawal symptoms.

Withdrawal symptoms may begin within a few hours of the person’s last dose. The most acute phase of withdrawal may last from four days to three weeks.

However, the fentanyl withdrawal timeline may vary depending on the person’s metabolism and how long they have been using the drug.

Some symptoms such as anxiety and depression may last for several months after the person’s last use of fentanyl.

Withdrawal Symptoms

The symptoms of fentanyl withdrawal can impact both physical and mental wellness.

These symptoms may include:

  • anxiety
  • depression
  • cravings
  • fatigue
  • difficulty concentrating
  • agitation
  • watery eyes
  • insomnia
  • sweating
  • yawning
  • runny nose
  • cramps and muscle aches
  • nausea and vomiting
  • diarrhea
  • dilated pupils
  • goosebumps


Detoxification occurs when a person ceases drug use. During detox, the person may begin experiencing the first signs of withdrawal.

Fentanyl detox will occur whether or not a person seeks treatment, provided that they do not take more fentanyl after they initially stop using it.

However, medical detoxification is a crucial step for many people with a substance use disorder.

Fentanyl withdrawal can be dangerous, so this step in substance abuse treatment provides the safest possible environment for detox.

Healthcare providers are available in case medical interventions become necessary. Furthermore, medical detox often includes withdrawal management treatment.

At a detox treatment center, doctors can help people transition from fentanyl to another opioid such as methadone.

From there, the person can taper off of opioids gradually, allowing the body to get used to the change over time.

Treatment For Fentanyl Addiction

After medical detox, inpatient and outpatient rehab programs can help people continue their recovery.

Both types of rehab facilities offer multiple treatment options such as individual therapy and group therapy.

After participating in a treatment program, many people seek long-term behavioral therapy to help them maintain sobriety and address any underlying factors that may contribute to addiction.

FAQs For Fentanyl Withdrawal

If you or someone you love are dealing with fentanyl addiction, it is natural to have several questions. Below are some of the most commonly-asked questions about fentanyl withdrawal.

A drug taper is one of the safest and most effective ways of dealing with fentanyl withdrawal. Tapering off fentanyl can reduce the risk of life-threatening withdrawal symptoms.

Medical detox has several benefits for people dealing with fentanyl withdrawal.

These benefits include:

  • decreasing the severity of withdrawal symptoms
  • providing a safe place to begin recovery
  • allowing the body to adjust over time
  • decreasing the chances of relapse

Fentanyl has an elimination half-life of eight to ten hours, which means that it takes roughly that amount of time for the body to eliminate half of the drug.

On average, it takes four to five half lives for a drug to completely leave the body.

However, different variables can affect how long opioids stay in the system, including metabolism and how long the person has used the drug.

The best medication for fentanyl withdrawal varies by person.

However, the most common medications for fentanyl withdrawal are other, less powerful opioids that can be tapered over time. Examples of these include methadone and buprenorphine.

Find Substance Use Treatment Today

Fentanyl addiction is a complicated disorder, especially as some people have consumed it accidentally and may not realize that they are dealing with this specific form of drug abuse.

Fortunately, treatment is available, and people do recover from fentanyl addiction. Call our helpline today for more information.

This page does not provide medical advice. See more

Addiction Resource aims to provide only the most current, accurate information in regards to addiction and addiction treatment, which means we only reference the most credible sources available.

These include peer-reviewed journals, government entities and academic institutions, and leaders in addiction healthcare and advocacy. Learn more about how we safeguard our content by viewing our editorial policy.

  • Was this Helpful?
  • YesNo
Medically Reviewed by
Johnelle Smith, M.D. on March 17, 2023
Let us walk you through the treatment process. We're here to help.
For 24/7 Treatment Help:
100% Free & Confidential. Call (844) 616-3400