How Does Fentanyl Affect the Brain?

Fentanyl is a powerful drug that latches to receptors deep within your brain. As soon as the drug crosses into the brain, people feel a reliable shift in their mood and emotions. 

While some people might describe fentanyl’s impact as pleasant, the changes aren’t good for either your brain or your body. In fact, one dose could cause such drastic changes that you lose your life. Or using the drug chronically could spark changes in the brain and body that make managing everyday life difficult. 

How Does Fentanyl Change Brain Chemistry?

We’re all born with opioid receptors dotting the cells in our brains. When people take fentanyl, the drug latches to those receptors tightly, causing a cascade of chemical and emotional changes. 

Opioids cause the brain to release huge amounts of dopamine — a neurotransmitter that regulates emotions and pleasure.[1] Some people experience euphoria due to this rush of dopamine. 

But brain cells aren’t designed for dopamine floods. Constant exposure makes them recalibrate, releasing less dopamine naturally. In time, people with opioid use disorder (OUD) produce much less dopamine without drugs. They may feel deeply depressed without it. 

Fentanyl also attaches to specialized proteins on the surfaces of brain cells, triggering the same processes you’d experience naturally in response to a pleasant event (like winning an award).[2] Even one dose can feel unforgettable because of this change, and people may be driven to repeat it because it felt so rewarding. 

How Dangerous Are Fentanyl’s Brain Changes?

Opioid receptors in the brain can alter more than your mood. Large changes could trigger a life-threatening episode. 

Changes to opioid receptors can change your respiration rate, causing you to breathe too slowly to support your body’s vital tissues. Your critical systems can shut down one by one, and while you may look like you’re just sleeping, you could be overdosing. 

More than 107,000 people in the United States died of drug overdoses in 2021, and about 67% of those deaths involved drugs like fentanyl.[3] This very strong and powerful drug causes such intense chemical transformations inside your brain that you could lose your life in minutes. 

Naloxone is a powerful overdose remedy. One dose kicks opioids off their receptors, rendering them inactive. Researchers say it can restore normal breathing within about three minutes of administration.[4] 

Since fentanyl is so strong, some people need multiple doses to recover from an overdose. But it can keep you from losing your life due to fentanyl misuse. 

An overdose is a significant health consequence of fentanyl misuse. But it’s not the only problem you might experience. With repeated use, this drug can change your brain cells so profoundly that it’s hard to quit. 

Chemical imbalances caused by fentanyl don’t magically disappear when you quit. Your brain cells need time to function properly without drugs, and sometimes, they need additional help.

Medications like Suboxone also latch to opioid receptors, but their weak attachment means they don’t trigger euphoria. They can help people feel fewer opioid withdrawal symptoms, and they can help you feel calm enough to focus on therapy. Some people take them for months, while others take them indefinitely. 

Returning to use after quitting isn’t uncommon, experts say.[5] But MAT programs can help to reduce the risk of a harmful relapse to fentanyl misuse.