How does heroin work?

Heroin works by affecting the opioid receptors in the brain, disrupting endorphin production. Heroin also depresses nervous system function. More on how heroin works in the body and the brain here.

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Heroin affects the brain, central nervous system and has effects all over the body. But, how exactly does heroin work in the body and brain? Does heroin have the same effect for everyone (especially heroin and teens)? We’ll explore these questions and more in this article. And we invite your questions about heroin at the end.

How does heroin affect the brain and nervous system?

Heroin effects the opioid receptors in the brain which disrupts endorphin production sent out to the rest of the body. This action is directly responsible for creating intense euphoria while suppressing physical pain and the reason why heroin also acts as an analgesic (pain killer) on the body system. Furthermore, heroin also depresses the central nervous system and the spinal cord. This chemical effect of heroin slows the motor functions which is why you feel so relaxed and out of it when you’re taking heroin. But heroin’s effect on the brain lead to to physical and psychological dependency on the drug. That is, over time, the body feels it needs heroin in order to function. And the mind cannot live without it (addiction).

How does heroin work in the body?

Is heroin addictive physically?  Yes.  Once heroin is in the system – either by smoking, snorting, or injection – it depresses the dopamine sensory pathways in the brain. This induces create a rush of euphoria. As the heroin rushes through the blood stream it warms the body. The extremities also become heavy and relaxed. Heroin can also produce dry mouth, nausea, and vomiting. It slows all functions of the physical and mental functions. But be warned: taking heroin just once can result in overdose and potential death. Heroin is unpredictable and how it’s going to affect your body changes between individuals who are taking heroin.

How fast or quickly does heroin work?

When heroin is directly injected into the blood stream , the effect of the high happens quickly after injection. You will feel in almost immediate rush and flush of the skin. This rush take about 6-8 seconds to happen. The peak effects of heroin can be felt about 10 minutes after injection. In contrast, intramuscular injection of heroin produces a relatively slow onset of euphoria (5 to 8 minutes). When heroin is sniffed or smoked, peak effects are usually felt within 10 to 15 minutes.

How long does heroin work?

Following heroin use, the intense euphoria lasts from 45 seconds to several minutes, peak effects last 1-2 hours, and the overall effects wear off in 3-5 hours, depending on dose. In fact, the high induced by heroin can last several hours after injection. While peak high symptoms happen about 10 minutes after injection effects such as drowsiness, relaxation, somnolence and disconnected from the world can last several hours after someone has injected heroin.

What makes heroin work better?

Heroin is an illegal drug and used for non-medical recreational purposes. And heroin works pretty well on its own. However, after continued use of heroin over the period of weeks or months, the phenomenon of tolerance can occur.  When you develop tolerance to heroin, it takes more heroin to produce the same initial effects. Some people use other substances to intensify the high brought on by heroin. Alcohol is popular substance used to increase a heroin high. But mixing heroin and alcohol should be avoided because it increase the likelihood of overdose and death.  Additionally, never increase doses of heroin drastically, or you could provoke overdose.

Does heroin work for everyone?

You never know how it’s going to affect someone. In general, heroin has a high potential to produce pain relief and euphoria in most people. And everyone has a potential to become dependent and addicted to heroin, resulting in heroin withdrawal syndrome when you stop taking the drug. However, some people may find themselves dependent on heroin and addicted to heroin much quicker than the next person who is taking heroin.

How does heroin work questions

Do you still have questions about how heroin works? Please leave your questions here. We will try our best to answer you personally and promptly. And if we don’t know the answer to your questions, we’ll refer you to someone who does.

Reference Sources: NIDA Research Report Series: How is heroin used?
Disease Reference Information

ANL: How Heroin works

NYC department of Health and medicine: Heroin addiction and Abuse
About the author
Lee Weber is a published author, medical writer, and woman in long-term recovery from addiction. Her latest book, The Definitive Guide to Addiction Interventions is set to reach university bookstores in early 2019.


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  1. People try to function because what else are they going to do? Nobody wants to be an addict. We tell ourselves that we will not use but we have a mental obsession with the drug that over rules everything. And one that mental obsession starts lying to us we think that we can use just a little bit and stop or that no one will know. But the reality is we have no control over the drug or the obsession. In my opinion the only way to get clean and stay clean is to have a spiritual awakening and completely change everything you do and your surroundings. Which is sometimes impossible or so it seems. So we try and try and try to function, sometimes we succeed and sometimes we fail miserably. But what else can we do???

  2. I have been dealing with my daughters Heroin addiction for 6 years. She’s been to treatment a few times and it’s been a long tough road for both of us. She relapsed again tonight. My question is why do they try to continue to function when they are in that state?

  3. Rick…absolutely!!! Being an addict is a terrible existence that only the addict can fix. Unfortunately the family can’t do any anything! But like Rick said, don’t turn your back. Continue to love and support the best you can and use tough love from a distance if you have to and do not enable. But that’s all you can do. An addict has to get clean for themselves. Best of luck guys. I’m an addict. I still struggle, but I am hopeful that I will get it someday!!

  4. Great article. The details you gave were extremely useful in my research on the affects heroin has. I learned a lot from this article.

  5. Hi I was just wondering how it enters the cells? passively or actively? also if it is endocytosis or exocytosis? Thank you

  6. Hi Everyone I am a heroine add coneing down as we speak please no one use this drug it has taken over my life took all my money and my man please stop using now I am done but hurting so so bad if some put one in front of me right now I would so do please pray I stay sober I will be praying for yu all two

  7. Hi

    Great site, very informative, thanks for your hard work and dedication.

    Now to my question…a doctor friends once told me that he didn’t consider heroin a recreational drug because, unlike people using E or Speed or such to get high and party, many heroin users choose that drug to self medicate, either because of mental issues, or previous emotional or physical abuse. He said something like “unlike party drug users, heroin users aren’t just trying to get high, they’re trying to fix or escape a problem in their lives, just doing in a particularly dangerous way”.

    What are your thoughts on that? Are heroin users more likely to be self mediators that made a wrong turn, or is it just a party drug.


  8. I was curious how long it takes the average person to build up tolerance for I.v heroin use and what is the minimum amount of time the average person should wait between doses…

  9. I’m writing an essay on heroin and I’d like to ask a question. If you’re injecting heroin, do you become completely incapable of moving, or can barely move at all? This is under the circumstances of injecting 3x the lethal dose of heroin. Would you be paralyzed?

    1. Hello Brar. I suggest you call the helpline number displayed on our site to get in touch with our trusted treatment providers who can help you access adequate treatment program.

  10. I am concerned because i take prescription pain medication. i know, that i m addicted to the opiate s it drives me crazy. if for some reason, i run out early , i wull go withdrawals. i. dont know what. to do. If i don’t have them in pain but then i have to put up wiith withdrawals. what can i do?

    1. Hi Shelly. Dependence is very different from addiction. If you have a chronic pain condition, then I assume you require a medication to help you function by lessening your pain. Speaking of dependence, that is the reason why you experience withdrawals when doses are reduced of stopped completely. Your body gets accustomed to the presence of the medication and needs it to be able to function. However, if you crave your medications to feel good, neglect yourself, your friends, life obligations etc. for the sake of obtaining and using your meds, then you should seek professional help.

  11. Where is heroin stored in the body? And would two bags of iv fluid sodium chloride flush my system of heroin used 24 hours earlier?

    1. Hi Aross. Heroin enters the blood stream and is moved through your organism through the circulatory system. Then it’s metabolized in the liver and quickly eliminated. If overused and the body cannot achieve to eliminate metabolites it has no other solution than to store it in the fat cells of the body.

  12. I actually have a question and a comment. I apologize if this is not the right place for a comment but I didn’t see any answers for people’s questions below. But first my question:
    Im curious about the psychological side. What exactly changes in the brain that causes the bi-polar symptoms (mood swings to be more specific)? And how long does it generally take for one’s brain to “balance out” after they get clean?
    Now my comment:
    For those asking what to do about their loved ones that are addicted to heroin, I’m sorry to say that there is no easy or good answer. I’m speaking as an addict myself who has had many friends and family try to “fix” me with often zero to disastrous effect. The best advice I can offer, is to inform yourself as much as you possibly can. Going to sites like this is a good start. But what these sites don’t mention is things like the obsession, the fear, the embarrassment, the self loathing/hatred and the wounded pride that most addicts deal with in their heads all day everyday. Addicts are afraid to ask for help yet at the same time were also afraid to accept it when it’s offered. We feel ashamed that we can’t fix ourselves. A lot of addicts take years to even realize or admit that we indeed do have a problem despite the fact that our loved ones have been telling us that the entire time. Unfortunately and addict cant be made to stay clean. They’ll only do that when they choose to do that. In the mean time love them, express your concerns and fears in a non-threatening manner. DO NOT enable them or bail them out of all their problems. Give them tough love without being a hard ass. Don’t cave when they beg you for things. Don’t allow them to push you away. Addicts tend to only surround themselves with people who can help them get their next fix. But most of all never forget that you will never ever truly understand what it is that their going through unless you’ve lived through it. And no addict would ever wish it on their worst enemy. Addiction is truly the Devils work.

    1. Hi Rick. Thank you for your question and for your helpful comment. And, unfortunately, although scientists are growing their knowledge about the way the brain functions and how drugs change chemical pathways, besides finding many answers, many more issues are left unanswered. One of the theories is that the damage heroin use can cause to this delicate chemical balance may be the reason heroin users develop bipolar disorder. The chemical chaos that heroin causes in the brain can be taken as a direct reason for displaying some bipolar-like symptoms, especially if the person is already prone to metal illness.

  13. I smoked it for three years family didn’t know I was doing it was one month shy of have being on it every day three time or more a day 4 years stright but my parent shipped me of to go live with my other parent I had to quite cold turkey no choice new state but I didn’t got threw withdraws or wanting it ether when I had to quite the people back home that I still was talking to was shocked by this saying that’s I possibale. But then why was I able to not have to go threw withdraws and the craving. So how is that possible since your the experts

  14. Hi Christine, I’m in the same place u are. I’m scared and have found my son overdosed in a car after searching for hours. I did get him medical attention. However, 2 rehab centers,jail and u name it, nothing

  15. Hello Christine. I’d suggest that you schedule an appointment with a licensed clinical psychologist who specializes in family addiction issues…tomorrow. Get yourself help and support so that you can be clear on how to live your life, and to separate your caring for him with taking responsibility for him. There is a light at the end of the tunnel. My best to you, Christine.

  16. This question is not for me it’s for my son. I know he’s using herion or some other kind of opiate. He swears he isn’t using but he is ! I don’t know anything about this god awful drug but I do no it’s destroying my child! Please how do I get him help He is 26 and i don’t know what else to do

  17. Tolerance does of course build up but this takes time and is not an overnight occurence and certainly not something that occurs between first trying the drug and the second time of using it. The term “chasing the dragon” refers specifically to a common method of administering the drug – that method being – smoking it on a piece of tin foil. Heroin prepared for smoking is put on a square/rectangle of foil and a tube is also made which is used to inhale through, the heroin is put on the rectangle of foil and the tube in the users mouth, the heroin is heated from below by a flame and turns from its powdered form to a viscous (thick) almost liquid state, the foil is angled so the now liquefied drug runs from one end of the foil to the other with the user following along behind (*CHASING*) the heated substance whilst inhaling the resulting smoke through the tube. The “dragon” in ‘chasing the dragon’ refers to the smoke inhaled from the heated heroin which is ‘chased’ back and forth along the length of the foil. The term was probably first coined by Chinese/asiatic users who have a strong affinity for dragons and an historic penchant for the smoking of opiates/opiods. “Chasing the dragon” is nothing, repeat nothing – to do with any requirement to increase ones dosage. New users should NOT and do NOT NEED to increase the amount of heroin they take from the first time to the second, any increase in dose should only occur when tolerance has been acquired and only then with great caution and awareness of what one is doing.


    Glastonicus Asiaticus.

  18. Hi Maria. Much research is currently been done into the way that drugs alter the brain. Search for these keywords for more information: brain opiate long term effect

    In terms of “worst” drug…by what measure?

    And I blog about addictions because a few years ago, there was no blog available which explored the medical issues around addiction. I blog to learn about addiction while at the same time, disseminate accurate information about addiction based on research and clinical studies.

  19. Hi, I have a few questions if you do drugs long enough, will your brain manipulte and stay that way? Also, is heroin the worst drug to take? One more thing, what made you decided to make a blog about addictions?

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