Patrick Slattery Fentanyl September 22, 2025 Have you ever quit taking a psychoactive substance after consuming it regularly? If you have, you know just how difficult it can be to do on your own. Fentanyl withdrawals occur because your body and brain have to readjust after you stop taking the substance. Common signs of withdrawal include flu-like symptoms and feelings of anxiety or depression. One of the biggest concerns surrounding fentanyl withdrawals is an overdose when cravings result in a return to use. Fentanyl was the single deadliest illicit substance in the state of Florida during the first half of 2024. At Real Recovery, we know that it’s possible to successfully make it through fentanyl withdrawals because we’ve empowered hundreds of people to recover. No matter where you are in your recovery journey, we’re here to help. Key Takeaways Fentanyl withdrawals happen when you stop taking the substance after you’ve developed a physical dependence on it. Anyone who takes fentanyl regularly is at risk of experiencing side effects when they stop taking it. Fentanyl withdrawals cause flu-like symptoms and psychological side effects like anxiety and depression. Acute fentanyl withdrawal symptoms are usually noticeable within 8 hours after your final dose, peak after about 3 days, and end within 10 days. If you’re like the majority of people with a fentanyl use disorder, you’ll experience intermittent cognitive symptoms due to post-acute withdrawal syndrome (PAWS) for several months after their last dose. Why Fentanyl Withdrawals Happen When you take a substance for an extended period of time, your brain and body adjust to having it in your system. This is known as physical dependence, and it can happen regardless of whether you’re taking a substance illicitly or as prescribed by a doctor. Fentanyl is an extremely powerful synthetic opioid. Once it enters your bloodstream, it breaks down, and the opioids in fentanyl attach themselves to the opioid receptors in your central nervous system. This triggers the release of endorphins and dopamine, which activate your brain’s reward system. This is what produces feelings of euphoria and pain relief that opioids like fentanyl are known for. Over time, your body will develop a tolerance, meaning it needs more and more of the substance to feel the same effects. Then, the naturally occurring endorphins and dopamine in your body will no longer feel sufficient. When you stop taking fentanyl, your body will want to maintain the chemical balance it’s become used to; that doesn’t happen, so the body goes into withdrawal. Given enough time, your body will readjust to the level of naturally occurring opioids in your system. However, fentanyl withdrawal causes a variety of physical and psychological symptoms. While these symptoms aren’t usually dangerous, they can be uncomfortable. Who’s at Risk of Experiencing Fentanyl Withdrawals? Fentanyl is arguably the most potent opioid on the market today. To put it in perspective, it’s estimated to be as much as 50 times stronger than heroin and 100 times stronger than morphine, according to the Drug Enforcement Agency (DEA). Because the substance is so strong, physical dependence develops quickly. You’re at risk of experiencing withdrawals if you take fentanyl regularly. This is true if: You have a prescription for fentanyl You consume other substances that are laced with fentanyl You’re living with a fentanyl use disorder Fentanyl is approved by the Food and Drug Administration (FDA) for certain pain management uses in clinical settings. If you have a prescription for fentanyl and you decide to stop taking your medication, you should work closely with your doctor to manage your side effects. Many people who consume other illicit substances take fentanyl without knowing it. This happens when dealers lace a substance with fentanyl to boost profits and enhance the psychoactive effects. When this happens, you could end up withdrawing from fentanyl without being aware that you’ve been taking the substance. You develop a fentanyl use disorder when you have a physical and psychological reliance on the substance. Because of your physical dependence on the substance, you’ll experience withdrawal symptoms when you stop taking fentanyl. How Do Fentanyl Withdrawals Affect the Body? Being able to recognize the symptoms of fentanyl withdrawal is key to preparing to end your consumption of the substance. The symptoms are often unpleasant, but they’re not usually dangerous. The most dangerous aspect of fentanyl withdrawal is the potential for overdose. It’s common for people to return to use during withdrawal, simply to end withdrawal symptoms. If you return to the dose you were used to before withdrawal, you risk overdosing, as your tolerance will be lower than it once was. You won’t necessarily experience every possible withdrawal symptom. Your specific symptoms depend on your body’s reaction to withdrawal. Physical Fentanyl Withdrawal Symptoms The physical symptoms of fentanyl typically mimic those of the flu. Common examples of physical symptoms of fentanyl withdrawal include: Stomach pain Nausea and vomiting Diarrhea Trouble sleeping Fatigue Fast heart rate High blood pressure Cold and/or hot flashes Chills Body aches and pains Runny nose and watery eyes These symptoms are uncomfortable but don’t usually cause long-term damage. The most serious risk to your immediate health is dehydration, which can occur as a result of heavy vomiting and diarrhea. It’s necessary to get plenty of fluids and rest during this time. Mental Fentanyl Withdrawal Symptoms In addition to physical withdrawal symptoms, you’ll also experience mental health symptoms when you stop taking fentanyl. 5 common mental symptoms associated with fentanyl withdrawal include: Intense cravings for fentanyl Mood swings Depression Anxiety and restlessness Problems with memory and focusing In some cases, people going through withdrawal have thoughts of suicide. If you’re concerned that you may hurt yourself or someone else, please call the 988 suicide hotline immediately. Understanding Acute Fentanyl Withdrawal Timeline The exact timeline of fentanyl withdrawal will vary slightly depending on a number of factors. These could include things like: Your metabolism The method you use to take fentanyl Your tolerance level The overall quality of your health Any other substance you take Keeping that in mind, the overall time frame for acute opioid withdrawal is fairly consistent. For most people, the timeline of fentanyl withdrawal looks like this: 3 to 4 hours after your last dose: With a fast-acting opioid like fentanyl, this is the earliest you may begin to feel the effects of withdrawal. At this stage, symptoms will be subtle, such as an underlying feeling of anxiety or a desire for more fentanyl. 8 to 24 hours after your last dose: At this point, you’ll begin to feel moderate physical withdrawal symptoms, including a runny nose, severe sweating, and chills. 2 to 3 days after your last dose: withdrawal symptoms will usually peak around day 3. At this stage, you’re likely to experience more intense symptoms, like vomiting, tremors, and an increased heart rate. Mental health side effects will accompany this. 7 to 10 days after your last dose: By about 10 days out from your last dose of fentanyl, most of your acute withdrawal symptoms will begin to subside. This means that your body has started to readjust to life without opioids. Post-Acute Withdrawal Syndrome (PAWS) and Fentanyl Many people with a fentanyl use disorder experience post-acute withdrawal syndrome (PAWS). In fact, some studies estimate that as many as 90% of people with opioid use disorder will experience PAWS. PAWS symptoms occur after the substance has completely left your system. They are mostly cognitive and psychological in nature. The timeline for PAWS is less concise. Symptoms usually come in waves and can take place months after you’ve stopped taking fentanyl. Typical symptoms of PAWS include: Sleep disturbances, including insomnia and vivid dreams Anxiety or depression Intense mood swings Cravings for fentanyl Trouble focusing Poor memory Sensitivity to stress Difficulty with fine motor skills Low enthusiasm or a general sense of apathy Poor impulse control Brain fog or trouble thinking things through Irritability, aggression, or hostility Get Treatment for Fentanyl Addiction at Real Recovery in West Central Florida Even when you feel ready to stop taking fentanyl, withdrawal isn’t easy, but it is the first step in the recovery process. You don’t have to do it alone. The right fentanyl addiction treatment will provide you with the tools you need to thrive in a life without illicit substances. This usually includes a combination of proven therapies, resilience development, and 12-step programming. Real Recovery Solutions provides the largest network of sober-living homes in the state of Florida. Here, you’ll be part of a large recovery community where you have constant access to peer support. Call us at 813-373-6762 to learn more about how we can help. Real people. Real solutions. Real Results. - Share on Facebook Share on twitter