
Heroin has a significant and negative impact on your brain, causing many changes at the neurotransmitter and receptor levels. Heroin affects the brain in many complicated ways, causing both short-term and long-term consequences. The main neurological complications include:[1]
Some types of heroin-related brain damage are permanent, while others can improve with time. No matter what type of damage has occurred, self-care can allow you to live with your new brain, make good choices and avoid further damage and complications.
For the best possible outcome, heroin use must stop promptly, medical care must be given, and addiction treatment must begin.
Heroin binds to three different opioid receptors in the brain: delta, kappa and mu. When heroin binds to mu-opioid receptors it causes a rush of dopamine to be released. [1] Dopamine is a neurotransmitter associated with pleasure, reward, and memory—it teaches us that certain behaviors are pro-survival and should be repeated.
Normally, these behaviors include natural rewards like having sex or eating food; however, heroin hijacks the brain’s reward system, causing a more intense reward than these natural ones and reinforcing the behavior, causing people to engage in compulsive heroin use.
Heroin is converted to morphine in the brain and binds to opioid receptors, causing a euphoric high. This causes immediate effects, such as:[3]
Heroin and other opioids cause slowed breathing and heart functioning by affecting the brainstem, the part of the brain responsible to automatic functions like breathing.[3]
When heroin binds to opioid receptors in the brain, it also blocks pain messages carried from the body through the spinal cord to the brain. This results in profound pain relief.[3]
Yes, researchers say heroin can cause brain damage, and some types of brain damage don’t require years of drug use to occur. Some people develop symptoms after their initial first few times using heroin.
These are the three types of damage associated with heroin:
Pure heroin is hard to find. Most street drugs are contaminated with heavy, solid substances like talc and chalk. Inject these items, and they can travel to brain tissues and clog delicate blood vessels. Brain tissues rely on oxygen, and when the delivery methods are blocked, they can starve and die.
Heroin use can also cause low blood pressure, resulting in low oxygen levels reaching vital brain tissue. People who use high doses of heroin may float into and out of consciousness, and their brain cells may die with each episode.[2] A heroin overdose causes even more damage, as tissues can be deprived of oxygen and nutrients for long periods. Even if you survive an overdose, your brain may not be the same.
Brain chemicals are profoundly changed by heroin.[3] Each dose produces a burst of dopamine, a natural substance that causes euphoria. In time, brain cells don’t produce sufficient amounts of dopamine unless potent drugs are used. Higher doses are required for the same effect—this is known as tolerance.
Quit using heroin, and your brain cells need time to adjust. While you withdraw, you may feel deeply depressed, as your body struggles to produce dopamine without drugs. Strong cravings for heroin may develop as your brain desires the substance they’re accustomed to. These cravings make relapse likely if you don’t have proper help.
Long-term use of opioids like heroin can change the shape and size of critical parts of your brain.
The frontal cortex is responsible for logic, setting goals, planning and self-control. In people with longstanding drug use, this part of the brain can be shrunken.[4]
Researchers also discovered changes in these portions of the brain in people with a long history of heroin use:[5]
Researchers aren’t sure why vital brain tissues shrink after long-term drug exposure. It’s possible that blood vessel damage and contaminants play a role. It is also theorized that some tissues may shrink due to the abundance of dopamine they’re exposed to with regular use.
People with a longstanding heroin addiction experience changes doctors may be able to see in brain imaging scans. But some types of brain changes can be hard to recognize.
Neurotransmitter changes aren’t noticeable until you stop taking drugs. Only then will you have a deep craving for drugs that seems impossible to ignore. Adjustments your brain made due to drug use are to blame for these intense cravings.
You may also feel a reduced ability to resist drug cravings. Tissue damage in the frontal cortex could make it hard for you to set solid plans and stick to them. Things that were easy before you started heroin use are suddenly very difficult.
People with brain injuries caused by heroin overdoses and oxygen deprivation can have trouble remembering information, including the following:[6]
Brain injuries can also cause difficulty in managing behavior and emotions. People may seem much more likely to get angry or upset than they did before the injury took place.[6]
Some types of heroin brain damage can heal with time and proper treatment. Other types are harder to address.
Neurotransmitter changes respond to Medication for Addiction Treatment (MAT) programs. Therapies like Suboxone (a buprenorphine and naloxone combination) can correct chemical imbalances and help people think clearly despite the damage done to their brain cells.
But brain damage caused by trauma or vascular disease is harder to fix. Brain cells don’t regenerate like other tissues within the body. People can learn to make new connections and strengthen their remaining skills. But the tissues that died or shrank may never come back or heal fully.
MAT programs are the best option for people with brain damage caused by heroin. Since this problem is so common among people who use drugs, almost everyone with an opioid use disorder should consider therapy with MAT.
Buprenorphine, a key component in Suboxone, is a partial opioid agonist. It latches to the same receptors used by heroin, but it doesn’t trigger euphoria in people with opioid use disorder (OUD). Instead, it soothes their damaged brain cells and relieves symptoms like drug cravings and heroin withdrawal symptoms.
Naloxone, the second component in Suboxone, works as a misuse deterrent. It can’t correct brain cell damage, but it can work as a backstop against overdose if people take too much.
Naloxone can kick opioids off their receptors and stop an overdose in progress. Since people with heroin-related brain damage struggle with self-control, this element is crucial. Relapse is more likely due to the brain damage heroin use can cause, but Suboxone acts as a safeguard against relapse.
Therapy provided in MAT programs can help people with heroin brain damage find new ways to think and react. For example, people struggling with out-of-control emotions like anger might learn breathing exercises to prevent violent outbursts. They might learn how a good night’s sleep is crucial to keeping their symptoms in check. And they might uncover the triggers that lead to their difficult emotions, so they can learn how to avoid them and better cope with them when they can’t be avoided.
The medication aspect of MAT programs is critically important to people with heroin-related brain damage. But therapy could be equally useful, especially during early recovery.
In therapy, patients build skills that help them to better manage relapse triggers and life in general. Because of this work, they are better able to deal with tough circumstances without returning to heroin use, and they simply enjoy life more as they learn to better manage their thoughts and emotions.
If you’re using heroin now and aren’t sure how to stop, talk to your doctor about enrolling in an MAT program. You can also reach out to us here at Bicycle Health to learn more about our telehealth addiction treatment offerings. We make treatment for opioid use disorder accessible, so more people can leave heroin use in their past.

Peter Manza, PhD received his BA in Psychology and Biology from the University of Rochester and his PhD in Integrative Neuroscience at Stony Brook University. He is currently working as a research scientist in Washington, DC. His research focuses on the role of the brain dopamine system in substance use disorders and in aging. He also studies brain function in obesity and eating disorders.
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