By Naomi Carr

Last updated: 21 December 2023 & medically reviewed by Morgan Blair

Fentanyl is a synthetic opioid analgesic medication, often prescribed to treat severe pain. It is available in various forms and brand names. This includes a lozenge (Actiq), buccal tablet (Fentora), sublingual tablet (Abstral), nasal spray (Lazanda), transdermal patch (Duragesic), sublingual spray (Subsys), and injectable liquids.[1]

Fentanyl is fast-acting and potent, with the potential for abuse, dependence, and addiction. Discontinuing fentanyl can cause withdrawal symptoms, so gradual tapering is recommended.

Does fentanyl cause withdrawal symptoms?

It is common when stopping fentanyl to experience withdrawal symptoms, particularly if the medication is abruptly stopped. Due to this, it is recommended to gradually decrease the dosage of this medication to reduce the risk of withdrawal symptoms.[2]

Fentanyl is an opioid, like heroin, morphine, and tramadol, although it is significantly more powerful than these drugs.[1] Fentanyl can create a feeling of euphoria or ‘high’, which contributes to its common misuse. As with other illicit and prescription opioids, fentanyl use can lead to tolerance, dependence, and addiction, which can increase the risk and severity of withdrawal symptoms.[3]

With prolonged fentanyl use, the risk of developing tolerance increases, meaning that the individual requires higher doses to achieve the same effect. Tolerance is likely to develop if the medication is misused, although can also occur in those who use it exactly as prescribed.[3]

If tolerance develops and doses are increased, the likelihood of physical dependence increases. This means that the individual needs to keep taking fentanyl regularly or they will experience physical and emotional effects, or withdrawal symptoms.[2]

Fentanyl withdrawal symptoms

When stopping fentanyl use, it is common to experience some withdrawal symptoms. These can be mild to severe and typically continue for up to ten days.

Common withdrawal symptoms

Common fentanyl withdrawal symptoms include:[3][4][5][6]

  • Nausea

  • Vomiting

  • Diarrhea

  • Stomach pain

  • Flu-like symptoms

  • Muscle and joint pain

  • Shaking

  • Tremors

  • Sweating

  • Sleep disturbances

  • Fatigue

  • Increased heart rate

  • Chills

  • Cravings

  • Anxiety

  • Mood changes

Rare or severe withdrawal symptoms

In some cases, fentanyl withdrawal symptoms can be severe and long-lasting. Rare or severe opioid withdrawal symptoms can include:[7][8]

  • Persistent vomiting or diarrhea, leading to dehydration and heart failure

  • Psychotic symptoms, such as hallucinations and paranoia

Fentanyl withdrawal timeline

When stopping or reducing fentanyl use, it is common to experience withdrawal symptoms within the first 24 hours. This risk is much higher if fentanyl is abruptly stopped, although withdrawal symptoms can also occur within this time with gradual tapering.[4] 

Withdrawal symptoms are likely to be at their most severe within the first few days and often reduce within ten days. However, for some people, symptoms can continue for several weeks and may be severe throughout this time.[4][7]

Factors influencing the severity and duration of fentanyl withdrawal symptoms include the type of fentanyl used, the method of administration, duration of use, dosage, additional substance use, and underlying mental or physical health conditions.[4]

Fentanyl cessation timeline

To safely reduce fentanyl, it is crucial to always follow the prescribing doctor’s advice. Abruptly stopping fentanyl or reducing the dose too quickly could result in severe withdrawal symptoms.[9]

A fentanyl cessation timeline will vary depending on the individual, the form and dose of fentanyl being taken, how the drug is administered, and the severity of withdrawal symptoms that occur.[4] 

With opioids, it is generally recommended to reduce the dosage by 10% every 1-4 weeks.[9] If minimal withdrawal symptoms occur, reductions can be larger and implemented over a shorter period. However, if unpleasant or severe withdrawal symptoms occur, slower and more gradual tapering is advised.

For example, someone taking 100mcg per day might reduce their daily dose by 10mcg every four weeks if they experience severe withdrawal symptoms. If severe withdrawal symptoms do not occur, it could be appropriate to halve the dose each week. A doctor should be closely involved in this process to monitor and manage any withdrawal symptoms and adjust tapering as required.[5][9]

Fentanyl is a very powerful medication. Because of this, it is important to be aware of the risk of overdose if fentanyl use is restarted or increased during the cessation period. Fentanyl overdose can be severe and even life-threatening.[2][9]

Fentanyl detox treatment

Coming off fentanyl, whether prescribed or otherwise, should only be done with professional advice and monitoring, as it can cause severe withdrawal symptoms. If an addiction and dependence on fentanyl has developed, the risk of severe withdrawal symptoms is increased. Detox should not be attempted without professional input, which could be provided in a hospital or detox facility.[9][10]

Individuals with a fentanyl addiction, other substance use disorder, or comorbid mental illness may benefit from psychological support during and following detox. This can help with managing withdrawal symptoms, coping with emotional distress, and planning for abstinence and recovery.[4][9]

Medications can be helpful during fentanyl detox, such as:[10][11][12]

  • Opioid agonists: Buprenorphine and methadone are medications often prescribed to help individuals through an opioid detox. These medications stimulate the same receptors in the brain as fentanyl and other opioids, helping reduce cravings and withdrawal symptoms. However, they do not create a ‘high’, so they are less likely to contribute to addiction and abuse. These medications can be used through the withdrawal process and then tapered or as a long-term treatment for opioid dependence.

  • Opioid antagonists: Naltrexone is a medication used in opioid use disorder. It prevents the drug from creating a euphoric feeling, thus deterring the individual from using it. However, it does not reduce withdrawal symptoms or cravings.

  • Non-opioids: Lofexidine and clonidine are medications that can help reduce withdrawal symptoms such as nausea and vomiting, pain, and flu-like symptoms. However, as they are not opioids, they do not reduce fentanyl cravings.

Recovering from an opioid addiction can take some time and may require ongoing support following the detoxification process. Some people may benefit from support groups such as Narcotics Anonymous, psychotherapy, holistic treatments, or medications such as antidepressants.[10]