One of the biggest problems that America faces is the opioid epidemic. Opioids were first pushed by the medical industry as a revolutionary miracle. These prescription drugs are effective painkillers and can be used in a wide variety of situations. Many doctors were happy to have these prescription drugs in their toolkit without realizing that they have a high potential for addiction.

Why Do People Take Fentanyl?

Fentanyl is no exception. This prescription painkiller was quickly introduced into the medical industry in the 1960s as an intravenous anesthetic.

As more people were prescribed these drugs for pain relief purposes, the prevalence of opioid addiction started to spike. On October 16, 2017, the U.S. government could no longer turn a blind eye to this growing problem and had to declare the opioid epidemic as a public health emergency. A lot of funding was given to addiction research to look for treatment solutions for fentanyl abuse.

Fentanyl is also commonly consumed unknowingly, as other recreational drugs are often cut with the substance. This unintentional use can be very dangerous, as people who unknowingly take fentanyl have no way of knowing or controlling how much fentanyl they consume.

“Fentanyl is 25 to 50 times more potent than heroin and 50 to 100 times more potent than morphine.”

What Harm Does Fentanyl Cause?

Although most people start taking fentanyl because of medical reasons, such as use during surgery, many will develop a dependence on the drug after using it for some time. Fentanyl causes the body to produce less dopamine and serotonin. Without the artificial influx of these neurotransmitters through fentanyl intake, these individuals will feel horrible.

Unfortunately, most people don’t realize that they may have become addicted or dependant on fentanyl until it’s too late. It’s crucial for these individuals to not allow their condition to worsen and to seek professional help, like with an inpatient treatment program. In this article, we’ll look at the signs and symptoms of fentanyl addiction, as well as the side effects associated with both short-term and long-term use.

Signs of Fentanyl Addiction

a red sign with addiction written on it

It can be difficult to recognize signs and symptoms of fentanyl addiction in both yourself and others, as many prescription drug users are quite high-functioning. This means that many people can carry on their daily routines and responsibilities despite being addicted and dependent on fentanyl.

Fortunately, addiction is a mental health disorder that has been researched extensively over the years by the American Psychiatric Association. This association has come up with the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), which uses 11 criteria to diagnose addiction. Signs of fentanyl addiction include:

  • Avoiding social, recreational or occupational activities in favor of taking fentanyl
  • Continuing to use fentanyl even if it leads to negative consequences
  • Continuing to use fentanyl even when faced with physical or mental health issues
  • Experiencing fentanyl withdrawal symptoms when attempting to quit
  • Experiencing cravings
  • Having to take larger amounts of fentanyl than prescribed
  • Having a desire to stop using fentanyl, but being unable to
  • Neglecting responsibilities at work, school or home to take fentanyl instead
  • Needing to take larger doses of fentanyl to achieve the same effects
  • Obsessing over fentanyl and spending a great amount of time trying to get, use or recover from it
  • Taking fentanyl even if it leads to dangerous situations

The severity of the addiction will depend on the number of criteria that the patient meets. For example, those who meet two to three of the criteria above are considered to have a mild addiction to fentanyl. Those who meet four to five criteria have a moderation addiction, while those who meet more than six criteria are severely addicted.

Understanding the level and severity of addiction can help medical professionals determine what course of action should be taken next. It will also provide further insight into how dangerous the addiction may be for each patient.

Other Behavioral Symptoms of Fentanyl Addiction

an individual holding an empty wallet

Although the DSM-5 is very insightful on defining signs of addiction, high-functioning users can still try to hide it. If you suspect that a loved one is struggling with fentanyl abuse, you might not necessarily be able to diagnose their situation using the DSM-5.

In these situations, it would be a lot easier to look for behavioral and emotional signs of abuse. Some of the most common signs to look for include:

  • Increased use of fentanyl
  • Doctor shopping, which involves going to more than one doctor at a time in an attempt to get more fentanyl
  • Intense mood swings, including irritability, anger and depression, on a regular basis
  • Social and interpersonal problems associated with fentanyl usage
  • An increased frequency of problems concentrating
  • Keeping empty bottles of fentanyl
  • Financial distress caused by purchasing fentanyl
  • Attempts to purchase fentanyl through illicit means
  • Flu-like symptoms, which are indicative of fentanyl withdrawal

Those who suspect that a loved one is struggling with fentanyl dependence should speak with an addiction expert. Only a specialist can help diagnose the situation and determine whether it’s severe enough to require medical intervention, like detox services.

When it comes to addiction, it’s always better to act sooner rather than later. With fentanyl addiction, a failure to act quickly can lead to devastating consequences.

Fentanyl Side Effects

Fentanyl alters neurochemical levels in the central nervous system (CNS) by binding to opioid receptors in the brain. Once the opioid receptors are stimulated, they will release an influx of neurotransmitters, like dopamine and serotonin, into the brain.  This action is responsible for regulating pain and emotions in the body, which is why fentanyl is so effective at treating pain.

Unfortunately, fentanyl use can lead to side effects. Patients need to be aware of immediate minor and major side effects that can emerge once they begin to take this prescription drug. Those who continue to take fentanyl for longer periods of time will also experience both short-term and long-term side effects as well. These side effects will vary slightly.

Immediate Minor Side Effects

Although fentanyl is effective, it will react in different ways in each patient’s body. Some patients will experience some mild to serious effects. In general, mild side effects will usually go away within a few days or a couple of weeks.

They’re not typically a concern, but those who notice these side effects worsening should speak with their doctor.

Some of the most common mild side effects include:

  • Redness and irritation of the skin (for transdermal patches)
  • Nausea and vomiting
  • Loss of appetite
  • Diarrhea or constipation
  • Increased sweating
  • Feeling cold
  • Headache
  • Difficulties sleeping
  • Dizziness and Fatigue

These side effects can also appear once again when a larger dose of fentanyl is taken. Once again, the side effects will usually disappear after some time, and patients should no longer be bothered by them.

Those who are struggling with minor side effects can consider switching to another type of opioid or opiate if these side effects do not appear to be getting better or if the side effects feel rather unbearable. There are many other options out there; however, the doctors may need to slowly taper the patients off fentanyl first in order to prevent withdrawal symptoms from emerging.

Immediate Serious Side Effects

911 on a mobile phone

Fentanyl will not necessarily agree with everybody. Some patients may experience some rather serious side effects, like the ones below:

  • Adrenal insufficiency
  • Androgen deficiency
  • Breathing problems, like difficulties breathing and shallow breathing
  • Fainting and confusion
  • Low blood pressure
  • Restlessness
  • Fast heart rate

Those who experience any of the side effects above should call 9-1-1 immediately, as these side effects can quickly become life-threatening. These patients should get their physical state and condition re-assessed in order to determine whether fentanyl may be too damaging for their body.

If it is, the medical professionals will wean the patients off this prescription drug and give them an alternative opioid or opiate for treating pain.

Acute Side Effects of Prolonged Fentanyl Use

From the moment that fentanyl enters the body, it will begin to have an effect on the neurochemicals within the brain, especially the dopaminergic and the serotonergic system. In fact, dopamine levels can jump as much as 200% within 8 seconds of taking an opioid, like fentanyl. The change in neurochemical levels is responsible for the short-term effects of fentanyl abuse.

Some of the most common short-term side effects documented amongst patients include:

  • Anxiety
  • Depression
  • Euphoric sensations
  • Constipation or diarrhea
  • Drowsiness and fatigue
  • Mood swings
  • Nausea and vomiting
  • Poor cognitive function and decision-making skills
  • Slurred speech

These side effects will usually disappear completely once fentanyl exits the body. The length of time that it takes for fentanyl to exit the body will depend on various factors, like the dosage and type of fentanyl that was taken and the height, weight and age of the patient.

The euphoric sensations experienced after taking fentanyl are what makes this prescription drug so deadly and addictive. Many people will chase these feelings.

Long-Term Side Effects of Extended Fentanyl Use

Although fentanyl consumption will lead to an influx of dopamine and serotonin levels in the body, this altered state is not permanent. Instead, the body will mistake the raised levels of these neurochemicals to be a sign that they should produce less of the neurotransmitters in question.

Those who take fentanyl for long periods of time will have tricked their bodies into believing that they should produce fewer and fewer of these chemicals. Instead, the body starts to rely on the artificial influx.

Since these neurotransmitters are crucial in regulating bodily functions, it’s not unusual for people to feel depressed and fatigued once the fentanyl leaves their system since their body has much lower levels of dopamine and serotonin than normal. The yearning for the artificial influx results in cravings, while the imbalance causes withdrawal symptoms to appear.

Those who take fentanyl for long periods of time are also at risk of developing long-term side effects like:

  • Coma
  • Brain damage
  • Bladder dysfunction
  • Bleeding ulcers
  • An increased risk for serotonin syndrome
  • Depression
  • Difficulties sleeping
  • Increased risk of infections
  • Fatigue
  • Kidney damage
  • Liver damage
  • Low libido
  • Increased pain sensitivity
  • Poor psychomotor skills
  • Seizures

The long-term side effects of fentanyl abuse can be quite damaging to the body. This dependence is also difficult to break free of, which is why it’s crucial for these individuals to seek professional help. They need to be under 24-hour supervision in order to ensure that they’re safe even if something goes awry.

Fentanyl and Serotonin Syndrome

There is a positive correlation between different types of opioid and opiate abuse, like fentanyl abuse, and serotonin syndrome. Studies show that those who take fentanyl for over 30 days will have an increased risk for developing this condition.

This condition happens when there is too much serotonin in the body. The excessive levels of this type of neurotransmitter will interfere with regular bodily functions, as it will overstimulate brain cells and nervous system cells; thus, preventing them from communicating effectively with one another.

The symptoms of serotonin syndrome will suddenly appear 6 to 24 hours after a dose is taken. Some of the symptoms to look out for include:

  • Agitation and confusion
  • Tremors and seizures
  • Dilated pupils
  • Hypertension
  • Sudden aggressiveness and irritability
  • Muscle spasms
  • Jerky eye movements
  • Restlessness
  • A general feeling of unease
  • Raised heartbeat
  • High blood pressure
  • Dry mouth
  • Diarrhea

In extreme cases, serotonin syndrome can lead to death, and the treatment for this condition is to discontinue using opioids or opiates.

Unfortunately, the medical community has yet to design a test that can confirm the presence of this condition. Instead, patients will need to rely on medical professionals to diagnose them based on their medical history.

Free Yourself From the Control of Fentanyl

a man standing on the summit of a mountain with outstretched arms

Opioid and opiate addiction isn’t something that should be taken lightly. Fentanyl in particular is a very dangerous drug since as little as 2 mg can be lethal. Unfortunately, those who are abusing fentanyl will easily reach this dosage. Those who take fentanyl for medical purposes should be careful, as they can easily become dependent on it if they aren’t careful.

Those who have already become dependent on this prescription drug and have noticed that they can’t function without it should seek professional addiction treatment. Look for facilities that offer evidence-based modalities, like Cognitive Behavioral Therapy (CBT) and Dialectical Behavioral Therapy (DBT), as these modalities offer the best shot at sobriety.

With professional help, many people who were once dependent on fentanyl have been able to break free from the shackles and get their lives back on track. With persistence and determination, they’ve been able to reach sobriety once again.

Fentanyl Addiction Resources

At, we are dedicated to helping people recover from problematic substance use and associated mental health disorders. If you or a loved one are struggling with addiction to drugs or alcohol, you are not alone. Information on treatment and support options is readily available through the National Helpline of the Substance Abuse and Mental Health Services Administration (SAMHSA) at 1-800-662-4357. To further assist you along the path to recovery, the treatment center locator on our website allows you to easily find rehabilitation programs and services in your local area.

We provide our readers with factual, evidence-based content concerning the causes and nature of addiction, as well as available treatment options. However, this informative content is intended for educational purposes only. It is by no means a substitute for professional medical advice, diagnosis, or treatment. With regard to any addiction-related health concerns, you should always seek the guidance of a qualified, registered physician who is licensed to practice medicine in your particular jurisdiction. You should never avoid or delay seeking professional health care advice or services based on information obtained from our website. Our authors, editors, medical reviewers, website developers, and parent company do not assume any liability, obligation, or responsibility for any loss, damage, or adverse consequences alleged to have happened directly or indirectly as a result of the material presented on

About the Author

Michael Couchman, PhD

Michael Couchman holds a Ph.D. in History from Queen’s University, where his research was focused on the origins of international drug control and legislative responses to problematic substance use. His award-winning doctoral thesis comparatively analyzed different official approaches to addictions treatment and their resultant public health implications. He has also written extensively about cannabis legalization in Canada, as well as the opioid crisis in the United States. In his current role at, he researches, writes, and edits helpful and informative content concerning the best available, evidence-based treatment options for those in recovery from drug and alcohol addiction.

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