Physical Effects of Heroin on the Body

Published On: November 1, 2023

Heroin is a highly illegal and addictive drug; it is a naturally occurring thought plan extract and transformed into a white power with a bitter taste. The greatest use is seen in adults from the ages of 18 to 25.

Heroin’s street colour is classically brown but can be cut with different substances. The smell can be odourless or vinegary.

There are three main ways to use heroin:

  1. Smoking (chasing the dragon): users heat heroin on tin foil and inhale the smoke
  2. By injecting it: Heroin is dissolved in water and injected into the veins, this is the most lethal form of use.
  3. Snoring: The most classic form of use.

Initial Reaction

A person with clasped hands, thinking

Heroin activates receptors in the brain called mu-opioid receptors (MOR’s). Our bodies contain neurotransmitters to bind to MOR’s in order to regulate hormones, pain and well-being.

When MOR’s are stimulated, they activate the release of dopamine, reinforcing drug-taking behaviour Consequences of activating these opioid receptors depend on how much is used and how strongly we bind to it. 1

Immediate short-term effects

Once heroin enters the body, it’s readily converted into morphine and binds to the receptors. This is when individuals experience their ‘high’ or ‘rush’.

The intensity of the rush depends on the amount used and the tolerance of the user.

The rush on the body is accompanied by:

  • Warm flushing of face and body
  • Dry mouth
  • Heavy feeling
  • Nausea and vomiting
  • Severe itching of skin

These are the immediate effects of a high, users will start to feel drowsy soon after.

Mental function becomes clouded and there is a dramatic slowing of bodily functions such as:

  • Slowing of heart rate
  • Slowing of breathing

This slowing can dramatically reduce bodily functions. If your heart and breathing are slow enough, it can be life-threatening. Slow breathing can lead to a lack of oxygen in the brain, a coma or even permanent brain damage.

Opioids can block transmitted pain messages via the spinal cord. Further, heroin can also alter activity in the limbic system, controlling emotions.

Long-term effects of heroin use

A man reading in bed

Repeated heroin use changes the structural makeup of the brain. The result is a long-term imbalance in hormone regulation that is difficult to reverse.

Heroin also tends to increase tolerance and physical dependence. This is because more of the drug is required to get the same effect. The body adapts to the constant presence of the drug, which is why withdrawal will be worse as use is reduced rapidly.

Heroin can also deteriorate the brain’s white matter, affecting:

  • Decision-making ability
  • Ability to regulate behaviour
  • Ability to respond to stress

Chronic users can face a plethora of health problems, from liver disease to hepatitis.

Liver and Kidney Disease


The Liver’s function is to filter out harmful chemicals and toxins from the body. The blood that leaves the intestines and stomach passes through the liver, processing and breaking down nutrients.

The liver metabolises drugs into forms easier for the body to get rid of. Not only is heroin already toxic to the body, but it can be cut with additives such as starch that can clog blood vessels.

The signs for liver disease consist mainly of jaundice and abdominal pain and swelling, similar to hepatitis.



Drug-induced Hepatitis is inflammation of the liver, caused by harmful and toxic chemicals. If there is too much toxicity in your liver, it can become badly damaged and result in hepatitis. If you have liver disease, you may be at higher risk in developing hepatitis.


  • Fatigue and weakness
  • Fever
  • Nausea and vomiting
  • Dark urine and pale stool
  • Jaundice (yellowing of skin and eyes)

Heart infections

A man taking off his glasses and rubbing his face

The drug itself slow both the respiratory system and heart rate, resulting in a high risk of pneumonia and other infections. 3

Infections of the heart lining and blood vessels are common. Heroin can lead to issues with the functioning of the heart. Opioids tend to cause problems with the contracting of the heart, which can lead to heart failure.

Street additives can clog blood vessels, which can result in an infection of vital organs, blocking the veins and restricting blood flow. This means heroin users are twice as likely to suffer a heart attack.

Ongoing chronic use can lead to ‘heroin heart’. Heroin heart is endocarditis, characterised by the infection of heart valves and inner lining. This can be spotted through night sweats, significant weight loss and blood in the urine.

An overdose of heroin can cause rapid heartbeat, leading to heart failure. If left untreated, an overdose can easily lead to death, so be honest with medical professionals.

Chronic constipation

A woman with her hands clasped and eyes shut

Heroin, along with other opioids, causes constipation. Reports show that as many as 80% of users experience constipation and bowel disorders.2

The reason most users get constipated is due to the dehydrating element of using. If you aren’t hydrated when you try and ingest food, the large intestine soaks up the water from your food.

Results of straining:

  • Haemorrhoids (swollen veins)
  • Torn anus skin
  • Stool that can’t be expelled
  • Rectal Prolapse (intestine protrudes from anus)

The slowing of bodily processes from heroin causes dramatic weight loss, this can be due to lack of appetite, and chronic fatigue. 3

 Diminished Sex Drive

A man looking fraught

Drugs affect the hormone balance in your brain. For certain drugs, this can manipulate your mood or desire to have sex.

Certain drugs such as heroin manifest this physically; vaginal dryness and decreasing blood flow can both make it difficult to have sex. This directly impacts libido.

Female and Male Infertility

Man lying down with his hand over his head

If use is prolonged, drugs can cause permanent problems with the reproductive system, causing infertility. This may be the result of the direct toxic effect; drugs disrupt an ovulation cycle, affecting the release of the egg. 3

There is a similar effect on men, reducing the sperm count, making it difficult to remain highly fertile.

Heroin can result in a miscarriage or stillbirth. Drugs travel through the placenta during pregnancy, causing the baby to become addicted, as well as the mother.

Drug use can cause deformities, strokes, and brain damage if the child lives through the pregnancy.

Skin infections

Repeated injecting and penetration of the skin can lead to venous sclerosis. This is also known as ‘track marks’, which can lead to:

  • Skin infections
  • Abscesses
  • Cellulitis

‘Heroin arm’ is a term that refers to the specific scaring from repeated drug use. The reason this is still used despite scaring is that it works quickly and is more effective. There are other risks associated with needle use, such as HIV and hepatitis.

HIV and Aids

HIV was first found in the early 1980s, where the virus attacks cells in the immune system. When HIV had destroyed a specific number of cells, the infected person then develops AIDS.

Although there is now medication to regulate the virus, it remains a life-threatening condition.


  • Rapid weight loss
  • Constant fever and sweating
  • Extreme fatigue
  • Swelling of glands
  • Long-term diarrhoea
  • Mouth, anus and genital sores
  • Pneumonia

Almost 40% of HIV occur among drug users that readily inject. There are multiple ways that heroin can lead to HIV:

  • Sharing contaminated needles
  • Sexual behaviour as a result of heroin: sex with multiple partners, sex with other drug users, sex in exchange for money, sex without contraception.

Heroin and Alcohol

Woman under a blanket, lounging on the sofa

Mixing opioids and ethanol can be lethal. Your body is put under so much strain with its level of toxicity, that an overdose is quite likely.

Effects of combination:

  • Dizziness
  • Confused coordination
  • Slowed breathing
  • Slow heart rate

The body absorbs alcohol quicker than usual with cocaine already in the system. As a duo-depressant, both alcohol and heroin make you feel down. Added together, their co-use can lead to a depressing comedown.

This effect can almost stop your breathing and reduce your heart rate massively. People also believe that drugs make them more ‘sober’, so are likely to carry on drinking. This can lead to a fatal overdose.

Heroin can have detrimental effects on the body. From a dry mouth to hepatitis, heroin can lead to detrimental and life-threatening consequences for your brain and body.

How to know if you are addicted to Heroin:

  • Increase in tolerance and consumption
  • Failing to stop or reduce use
  • Sacrificing family, friends or activities to use
  • Anxiety and mental health issues
  • Financial strain
  • Lack of sleep

If you think you might require a detox or have any questions, don’t wait to contact us.


  2. Sizar O, Genova R, Gupta M. Opioid Induced Constipation. [Updated 2021 Aug 11]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2021 Jan-. Available from:
  3. LeVert, S. (2006). The Facts about Heroin. United States: Marshall Cavendish Benchmark.
  4. Downes, P. (2003). Living with Heroin: Identity, Social Exclusion and HIV Among the Russian-speaking Minorities in Estonia and Latvia. Estonia: Legal Information Centre for Human Rights.
  5. Kreek MJ. Opioid interactions with alcohol. Adv Alcohol Subst Abuse. 1984 Summer;3(4):35-46. doi: 10.1300/J251v03n04_04. PMID: 6391108.
  6. Li, W.; Li, Q.; Zhu, J.; Qin, Y.; Zheng, Y.; Chang, H.; Zhang, D.; Wang, H.; Wang, L.; Wang, Y.; Wang, W. White matter impairment in chronic heroin dependence: a quantitative DTI study. Brain Res1531:58-64, 2013.

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