Detox from Heroin Now
Call Now To Get Help
1-888-496-8059 Who Answers?

Heroin Effects on the Brain

Regardless of the person’s age, substance use and abuse may come with an array of harmful consequences.1 But it is chronic and prolonged abuse of heroin and its effect on the body and mind that is especially concerning, as it raises the risk of becoming addicted to the drug. This further raises the risk of suffering potentially severe and lasting damage to the brain, as well as that of a potentially fatal heroin overdose.1 

A range of factors determine whether a person will develop an addiction, but the earlier people start using heroin, the more likely they are to develop an addiction, especially if they are smoking or injecting the drug.1 On the other hand, the earlier they seek comprehensive treatment, the better chances they have of overcoming addiction, counteracting the potentially devastating long-term effects of heroin and undoing the damage the drug has caused to their body and mind.1

Short and Long-Term Mental Damage 

Repeated heroin use can affect the way a user thinks and acts because it changes the brain’s physical structure and physiology. It creates long-term imbalances in the neuronal and hormonal systems. Mental damage caused by heroin is not easily reversed.2

To complicate matters further, heroin can produce tolerance and physical dependence which means the person needs to gradually increase their intake of the drug to achieve its initial effect which puts them at risk of physical dependence.2 

If a person has become physically dependent on heroin, they experience intense cravings for the drug and can no longer function without it: the body has adapted to the presence of heroin and if the supply of the drug is abruptly reduced or discontinued, the person undergoes extremely unpleasant physical withdrawal symptoms.2

With prolonged repeated heroin use, especially if the drug is smoked or injected, the person progresses into the final stage: heroin use disorder. The disorder is a chronic, relapsing disease characterized by compulsive, uncontrollable drug-seeking behavior. The person loses interest in all other activities except seeking and using heroin.2

It is worth noting that even occasional heroin use can lead to disastrous consequences such as overdose.1

How Does Heroin Work in the Brain?

Heroin interferes with the natural process of neurotransmission. The role of neurotransmitters is to enable communication between neurons, which are responsible for sending, receiving and processing signals.1

Heroin mimics the structure of a natural neurotransmitter which enables it to activate neurons. This abnormal activity disrupts the natural functions of the brain and the normal communication between neurons.1

Repeated heroin use can cause deterioration of the brain’s white matter, which is responsible for the person’s decision-making abilities, the ability to regulate behavior, and the ability to respond to stressful situations.2

However administered, heroin is highly addictive and enters the brain rapidly.3 However,  smoking or injecting heroin allows the drug to reach the brain the fastest, which considerably increases the risk of developing heroin use disorder.2

What Are the Short-Term Effects of Heroin Abuse on the Brain? 

Upon entering the brain, heroin is converted to morphine and binds rapidly to opioid receptors.3 Common short-term effects of heroin on the brain include feeling a surge of intense pleasure, or euphoria, clouded mental functioning and the state of being drowsy, going back and forth between being conscious and subconscious, which is followed by other physical effects.4

The intensity of the rush depends on two key factors that include:3

  • The amount of heroin taken.
  • How rapidly heroin enters the brain and binds to the opioid receptors, which depends on the route of administration.

Since heroin can severely slow down respiratory and heart function, its effects can be life-threatening and lead to coma and lasting brain damage.3

What Are the Long-Term Effects of Heroin on the Brain?

Heroin addiction can have a damaging long-term effect on the body and mind. Common long-term effects of heroin on the brain include mental health disorders such as depression and antisocial personality disorder.4 But heroin can also cause permanent damage to the brain, as long-term heroin use can impair brain functioning.4

Can Brain Damage From Heroin Abuse Be Reversed?

Heroin addiction is considered to be a chronic, relapsing yet manageable condition.1 Seeking heroin addiction treatment is considered to be the only way to put the condition under control and treat or reverse the brain damage it has caused.1

Find Out How to Reverse Heroin Brain Damage.Discuss your treatment options in absolute confidence. 1-888-496-8059 Who Answers?

Frequently Asked Questions

How Does Drug Addiction Affect the Brain?

Drug addiction is considered a chronic brain disease that can impact and alter various areas of the brain:1

  • The basal ganglia are involved in the formation of habits and routines and constitute the brain’s “reward circuit.” When drugs produce euphoria, they over-activate this circuit. Repeated exposure to the drug disrupts the circuit and causes it to become adapted to the presence of the drug.

As a result, the person’s sensitivity is greatly diminished and they gradually lose the ability to derive pleasure from positive forms of motivation and healthy pleasurable activities such as eating, sex, and socializing.

  • The extended amygdala plays an important role in emotional processing, including stress-related emotions such as irritability, anxiety, and unease. Withdrawal from a drug triggers these emotions which then drive the person’s drug-seeking behavior. The higher the intake of the drug, the more sensitive this area of the brain becomes.

Once a person’s repeated substance abuse has progressed into a substance use disorder, they need the drug to escape this discomfort, but they can no longer derive pleasure from it.

  • The prefrontal cortex is responsible for cognitive processes: thinking, planning, problem-solving, decision-making, and impulse control. Drugs can interfere with that. The prefrontal cortex is the last area of the brain to mature, which is why early substance abuse can be especially dangerous as it can make teenagers extremely vulnerable to developing an addiction.
  • Opioids such as heroin can also disrupt other parts of the brain such as the brainstem which regulates life-sustaining functions.

How Do Opioids Affect the Brain?

Opioids such as heroin cause extreme euphoria followed by intense feelings of relaxation and satisfaction, reduce feelings of pain and disrupt parts of the brain essential to controlling and regulating automatic functions.

The effects of opioids on the brain are complex and the consequences may be far-reaching:1

  • Effect on the brain’s neurochemical activity: Opioids are depressants, which means they can slow down or even stop breathing and other automatic body functions.3  Heroin and other opioids can produce a life-threatening or lethal reaction.4 

The risk of a fatal or non-fatal overdose is especially high when a person injects a high dose of heroin: the drug enters the bloodstream immediately and reaches the brain rapidly.1 A person who relapses after attempting to quit may also overdose if they take the usual amount of the drug since their body is no longer adapted to that level of exposure.1.

  • Effect on the limbic system which controls emotions.4 By changing activity in it, opioids can reinforce drug-taking behavior.
  • Effect on neurotransmission: Opioids can mimic one or more neurotransmitters and block pain messages transmitted through the body, which is why they are so effective as pain relievers.5 The intense effect of opioids such as heroin can produce an abnormal response in the opioid receptors and cause a massive amplification of opioid receptor activity.5

What Part of the Brain Is Responsible for Heroin Addiction?

The feeling of pleasure plays an important role in a healthy brain, as it helps us identify and reinforce healthy behaviors. We are hard-wired to repeat pleasurable behaviors and experiences which trigger our reward circuit in the brain and cause a burst of the neurotransmitter dopamine. This is how healthy, desirable habits and routines are formed.1

But the problem is that the mechanism is the same when it comes to unhealthy, detrimental habits such as drug-seeking behavior and drug use. Namely, drugs such as heroin produce intense euphoria and an intense surge of dopamine.1

In doing so, they reinforce the connection between drug use and the pleasure derived from it. This learned reflex can cause lasting changes in the reward circuit. The brain also remembers any external cues associated with the experience, which can trigger uncontrollable cravings even in people who have been off heroin for a decade.1

How Does Heroin Cause Tolerance?

Normally, people have the ability to derive pleasure from naturally rewarding (reinforcing) activities. With prolonged, repeated use of heroin, the person loses this ability. This is because, unlike natural rewards, drug rewards have an abnormal effect on the brain. The person enters a vicious circle in which they can no longer enjoy other activities that they used to find pleasurable and can only derive pleasure from seeking and using heroin.1 

Because of heroin’s potent effect on the reward system in the brain, the person needs to maintain a consistent level of exposure to heroin to experience a normal level of reward. Repetitive use of heroin leads to increased tolerance to the drug and the person needs increasingly high doses to experience the familiar high. The next step is physical dependence.1

Why does heroin cause dependence?

Repetitive use of heroin leads to a physical dependence on the drug. If the person tries to abruptly reduce the supply or level of exposure to the drug, they can undergo withdrawal symptoms.1

How Is Heroin-Induced Brain Damage Treated?

Comprehensive treatment which involves detoxification and physical stabilization and long-term therapy is considered to be effective at treating heroin addiction and brain damage.1

Medication-assisted treatment (MAT) is considered to be most effective at addressing opioid and heroin addiction: MAT uses medications as the first line of treatment, both during detoxification and rehabilitation, and incorporates behavioral therapy and/or counseling.1

Find Out How Treatment Can Reverse Heroin Damage. Consult an admissions navigator to help you decide on your next step. 1-888-496-8059 Who Answers?


  1. National Institute of Drug Abuse. (2014). Drugs, Brains, and Behavior: The Science of Addiction
  2. National Institute of Drug Abuse. (2020). What are the long-term effects of heroin use?. 
  3. National Institute of Drug Abuse. (2020). What are the immediate (short-term) effects of heroin use?.
  4. National Institute of Drug Abuse. (2019). Heroin DrugFacts
  5. National Institute of Drug Abuse. (2017). Impacts of Drugs on Neurotransmission

Are You Ready to Get Help?

Call Now to Speak to a Treatment Specialist

1-888-496-8059 Who Answers?

Help for Heroin Addiction

Do you know someone suffering from heroin addiction? Help is available. To find out more, please choose the selection that applies to you or the person suffering from addiction:

Fill out the form below to be contacted.

Repair the damage and start fresh today!

Or call this number to speak with a caring advisor now.

1-888-496-8059 Who Answers?
Please Don't Wait Until It's Too Late 1-888-496-8059 Who Answers?
Finding What You're Looking For?
  • Try: [url link="city_link"][city] Heroin, Drug and Alcohol Treatment Centers[/url]
  • Or View All: [url link="region_link"][region] Rehab Programs[/url]
  • Or use our fast and easy Site Search!