Harm reduction

Naloxone at a needle exchange in Birmingham, UK. Nigel Brunsdon/nigelbrunsdon.com

Key points

  • Harm reduction aims to reduce the negative impacts of drug use on the health of people who use drugs.
  • It helps prevent overdoses and reduce the transmission of HIV, hepatitis B and hepatitis C.
  • There is better provision of needle and syringe exchanges and opioid agonist treatment than other types of harm reduction, but they are still unavailable in many places.
  • Take-home naloxone programmes, supervised consumption facilities and drug-checking services are even less accessible. 

Harm reduction refers to the set of laws, policies, programmes, and services designed to reduce the negative impacts of drug use on the physical, mental and social wellbeing of people who use drugs. Harm reduction aims to support people who use drugs and their communities without judgement, discrimination and with no condition of stopping drug use. Harm reduction encompasses a wide range of health and social services, including sharing of information on the safer use of drugs, needle and syringe exchange programmes, overdose prevention, opioid agonist therapy, drug checking, supervised consumption sites, and legal services.

For people living with HIV, it is important to know that some of the recreational drugs commonly used may interact with your HIV treatment. This interaction can reduce the effects of the HIV medications or increase the effects of the recreational drugs you take. There’s more information on the interaction between HIV treatment and recreational substances on another page.

Harm reduction is proven to be effective in keeping people alive by preventing overdoses, reducing transmission of HIV and viral hepatitis, and improving overall individual and community health. While abstaining from drugs may be possible for some people, it is not be possible for many others. That is why the primary goal of harm reduction is to reduce infections, illnesses, overdoses and death while providing continued support for people who use drugs. 

According to Harm Reduction International, each year around 275 million people use drugs worldwide. However, 191 countries have policies that criminalise drugs while 35 countries still retain the death penalty for drug offences.

Needle and syringe exchanges

Also known as needle and syringe programmes (NSP), they allow people who inject drugs to dispose of their used injecting equipment and access free and sterile equipment. By reducing the sharing and re-use of injecting equipment, needle and syringe exchanges help prevent the transmission of HIV and viral hepatitis.

With evidence from over four decades, needle and syringe exchanges are proven to be cost-effective and prevent the transmission of blood-borne viruses. Although needle and syringe exchange programmes are the most widely implemented harm reduction service, global coverage remains low, with only 94 countries implementing them in 2022. 

Most needle and syringe programmes also provide additional services such as HIV and hepatitis screening, counselling, education on how to inject safely and prevent overdoses, vaccinations, wound care, mental health support and referral to other health services. Through information sharing and continuous support, needle and syringe exchanges can increase the uptake of HIV screening, improve adherence to medication, and make referrals to addiction treatment and other health services.

Opioid agonist treatment  

Opioid agonist treatment (OAT) is also known as opioid substitution therapy (OST), medication assisted treatment (MAT) and medication for opioid use disorder (MOUD). It is a harm reduction approach that includes providing users of opioids (such as heroin, morphine, codeine and fentanyl) with a less harmful replacement drug under medical supervision. Replacement drugs include methadone, buprenorphine, slow-release oral morphine and medical-grade heroin. Some programmes also provide access to other drugs that block the effect of opioids such as naltrexone.

Because stopping drug use is not always possible for people, opioid agonist treatment supports people who use opioids by providing access to long-acting opioids to reduce their dependency on the short-acting, more harmful opioids. The long-acting opioids do not get a person high but prevent withdrawal and reduce cravings. They may be taken orally rather than by injection. Opioid agonist treatment allows the person not only to reduce their dependency but also to focus on other aspects of life and things that have led to opioid use. That is why the treatment works best when it is provided alongside other services including HIV testing, individual counselling, and support groups.


harm reduction

Harm reduction is a set of practical strategies and ideas aimed at reducing negative consequences associated with drug use (including safer use, managed use and abstinence). It is also a movement for social justice built on a belief in, and respect for, the rights of people who use drugs.

drug interaction

A risky combination of drugs, when drug A interferes with the functioning of drug B. Blood levels of the drug may be lowered or raised, potentially interfering with effectiveness or making side-effects worse. Also known as a drug-drug interaction.


How well something works (in real life conditions). See also 'efficacy'.

opioid agonist therapy (OAT)

Providing users of an illegal drug (such as heroin) with a replacement drug (such as methadone, buprenorphine or naltrexone) under medical supervision. This helps the person reduce the frequency of injections and their dependency on illegal drugs. It is part of a harm reduction approach.



opioid substitution therapy (OST)

Providing users of an illegal drug (such as heroin) with a replacement drug (such as methadone, buprenorphine or naltrexone) under medical supervision. This helps the person reduce the frequency of injections and their dependency on illegal drugs. It is part of a harm reduction approach.



Opioid agonist treatment programmes increase the uptake of HIV testing among people who use opioids and can encourage people to initiate HIV treatment. The risk of interaction between opioids and antiretrovirals used in HIV treatments is low and opioid agonist treatment is proven to improve quality of life and adherence to HIV treatment for people living with HIV.

Opioid agonist treatment programmes were implemented in 90 countries in 2022, an increase on previous years. However, they are unavailable in many regions and prohibited by law in some countries. 

The medication used can come in the form of a drink, a pill you place under your tongue or an injectable. Some people experience side effects such as light-headedness, dry mouth, changes in sex drive and sweating when they start opioid agonist treatment. Usually, these go away after a few days, and you can always talk with your doctor about anything you experience that you think may be a side effect. 

Take-home naloxone programmes

Naloxone is a medication that blocks the effects of opioids in order to prevent an overdose, the leading cause of death among people who use heroin and other opioids. Naloxone was added to the list of essential medicines by the World Health Organization in 1983 and is widely used worldwide by healthcare providers to reverse the effects of an opioid overdose. It has no effect on non-opioid overdoses, no potential for dependency and is safe to use.  

Take-home naloxone programmes make the medication available for free and without a prescription to people who use drugs and others who are more likely to witness an overdose, including drug users’ partners, friends, and family. Training on recognising an overdose and administering naloxone should be provided as part of a take-home naloxone programme. However, only 43 countries implemented take-home naloxone programmes in 2022

Currently, naloxone is available in different forms. It can be injected into the muscle, under the skin and into the veins. A nasal spray formulation was approved by the European Commission in 2017, and it is increasingly becoming more accessible in many European countries. 

Naloxone comes with a patient information leaflet and instructions. Because it should be used only when an opioid overdose is known or suspected, it must be given by someone else. You can talk with people close to you so that they know what to do in case of an emergency. The most commons signs of an opioid overdose are breathing problems including slowed or stopped breathing, loss of consciousness and unresponsiveness. First responders or emergency services should be called in case of a suspected overdose and the use of take-home naloxone can be lifesaving until the emergency medical team arrives. If you do not know how to use naloxone, let the operator on the phone know you have it and follow their instructions.

Supervised consumption facilities

Supervised consumption facilities are also known as drug consumption rooms, safer injection facilities and overdose prevention centres. They are safe and clean spaces where people can bring their own drugs to use under the supervision of medically trained staff.

Facility staff do not directly assist in the consumption of the drugs brought in by the clients. They are there to provide sterile equipment, answer questions and provide information on safe injection practices, monitor for an overdose, and administer first aid if needed. The staff at these clinics are in regular contact with people who inject drugs at the facilities, enabling them to share general medical advice and make referrals to medical and social services. 

They are proven to prevent accidental overdoses, reduce infections caused by needle and syringe sharing, and increase the delivery of medical and social services to people who inject drugs. Although the history of safe consumption sites dates back to 1912 in the US, these clinics were closed by the federal authorities in the early 1920s. Later, the first modern supervised consumption site was opened in Bern, Switzerland, in 1986. In 2022, only 17 countries implemented supervised consumption facilities, 12 of them in Europe.

Drug-checking services

Drug-checking services provide information about the content and safety of substances bought in unregulated drug markets. People can anonymously submit a small portion of the drugs they intend to use for chemical analysis. The results are shared with the person in a counselling session to inform them of the exact content of the substances they intend to use and their potential effects. This gives the person the chance the re-evaluate their consumption and make an informed decision.

Drug-checking services are effective in raising awareness, preventing fatalities, and reaching people who are not regular users. They also allow monitoring of substances in circulation (including new synthetic drugs) and allow health services to prepare for emergency cases. 

Drug-checking services remain controversial; with most implemented only for the short term at music festivals and in research studies, the number of people accessing services is very limited. In 2022, the drug-checking services were the least available harm reduction service, only available in 26 countries globally.

The Trans European Drug Information network provides details of drug-checking services in Europe.

You can get more information on harm reduction in this free online training, offered by Mainline, a Netherlands based organisation, as part of their Harm Reduction School.

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