Is Heroin Used Medically? Uses, Risks, and Bans

Heroin, known in clinical settings as diamorphine or diacetylmorphine, is used medically in a small number of countries, most prominently the United Kingdom. There it remains a licensed pharmaceutical prescribed for severe pain, heart attacks, and end-of-life care. Most of the world, including the United States, bans any medical use of heroin outright. The gap between these two realities tells a more complicated story than the drug’s street reputation suggests, touching on pain treatment, addiction medicine, health economics, and the politics of drug scheduling.

Diamorphine as a Prescription Painkiller

In the UK, pharmaceutical-grade heroin goes by its generic name diamorphine and is listed in the British National Formulary, the standard prescribing reference used by doctors and pharmacists. Its approved indications include acute and chronic severe pain, acute pulmonary oedema (fluid in the lungs), and pain from myocardial infarction (heart attack).¹ A survey of British general practitioners and hospital doctors found that the four conditions most commonly prompting a diamorphine prescription in the previous year were myocardial infarction, palliative care, pulmonary oedema, and post-operative pain.²

Why use diamorphine when morphine is available everywhere? The answer is practical. Diamorphine is highly water-soluble, meaning a clinically useful dose dissolves in a very small volume of liquid. That makes it easier to inject subcutaneously through a syringe driver, a portable pump commonly used in palliative care when a patient can no longer swallow pills. Morphine requires a larger volume for the same effect, which can cause discomfort at the injection site. For end-of-life care, where comfort is the entire point, this difference matters.

Diamorphine also appears in British paediatric emergency medicine. A nasal spray formulation, dosed at 0.1 mg per kilogram of body weight, has been used to treat acute pain from fractures in children. In an observational study of 226 young patients who received intranasal diamorphine, no serious adverse events occurred, no respiratory depression was reported, and side effects were mostly mild nasal irritation.³ A randomised controlled trial comparing the nasal spray with intramuscular morphine injections found that pain relief started faster with the spray and that the experience was far less distressing for the child. Staff and parents rated the spray acceptable for about 97-98% of patients, compared with much lower ratings for the injection.⁴ For a child with a broken arm, a quick spray up the nose beats a needle in the muscle.

In labour and delivery wards, diamorphine is sometimes combined with local anaesthetics for epidural pain relief. Research on epidural diamorphine paired with levobupivacaine found that the two drugs work together additively when given during the first stage of labour.⁵

Why Most Countries Do Not Allow Medical Heroin

Outside the UK, medical use of diamorphine ranges from rare to completely prohibited. The United States classified heroin as a Schedule I substance under the Controlled Substances Act of 1970, meaning it is deemed to have no accepted medical use and a high potential for abuse. That scheduling effectively bars any clinical prescription, even in hospital settings. Canada, Australia, and most European countries similarly restrict diamorphine, though some have carved out exceptions for supervised treatment programmes (discussed below).

The reasoning behind these bans is partly pharmacological and partly political. Diamorphine converts rapidly to morphine in the body, and critics argue that morphine and other available opioids can achieve the same clinical results without the stigma and diversion risks associated with heroin. The UK’s continued use of diamorphine is sometimes treated as an anomaly, a holdover from a medical tradition that never fully broke with the drug. British doctors tend to view it as simply another strong opioid in the toolkit, while in countries where it was banned decades ago, the association with illicit use is too powerful to overcome through pharmacology alone.

The practical effect of these bans is that if you are hospitalised in the United States, Germany, or Japan, you will never receive diamorphine regardless of your condition. If you are in a British hospital with a heart attack or dying of cancer, you might. The drug itself has not changed; the legal and cultural framework around it has.

How Heroin Works in the Brain

Heroin is a prodrug, meaning it does not do much on its own. After injection or inhalation, the body rapidly converts it into morphine and an intermediate compound called 6-monoacetylmorphine. These active metabolites bind to opioid receptors concentrated in brain regions involved in pain, reward, and basic survival functions like breathing and appetite. The euphoria that makes heroin appealing to recreational users comes mainly from activation of mu-opioid receptors in the brain’s reward circuitry, particularly within the nucleus accumbens.⁶ Those same receptors also suppress pain signaling, which is why heroin and its metabolites are powerful analgesics.

The speed of onset is what distinguishes heroin from morphine clinically and recreationally. Because diamorphine crosses the blood-brain barrier faster than morphine does, the subjective effects hit more quickly. In a medical setting, that speed is useful for acute emergencies like heart attacks, where rapid pain relief matters. In a recreational setting, that speed is what produces the “rush” and makes heroin particularly reinforcing and addictive.

The Primary Medical Risk Is Stopping You From Breathing

Respiratory depression is the chief danger of any opioid, and heroin is no exception. The same mu-opioid receptors that kill pain also dampen the brainstem’s drive to breathe. A study monitoring patients after diamorphine injection documented prolonged pauses in breathing exceeding 20 seconds, with the longest lasting 56 seconds. Blood oxygen levels dropped significantly, with one patient’s oxygen saturation falling as low as 80%, well below normal.⁷

What makes this particularly treacherous is that oxygen levels can stay deceptively close to normal even when the brain’s respiratory drive has already been suppressed. Research on injectable pharmaceutical heroin found that blood oxygen readings sometimes remained near baseline despite significant drops in the neural signal telling the lungs to breathe. Patients with lower baseline respiratory drive were more vulnerable to oxygen desaturation after receiving the drug.⁸ This disconnect between what a pulse oximeter reads and what the respiratory system is actually doing helps explain why overdoses can progress from fine to fatal with little warning.

Respiratory depression is a fundamental property of all drugs that activate mu-opioid receptors. Comparative research on morphine, oxycodone, heroin, and fentanyl found that each one reduced oxygen levels in the brain, confirming that brain hypoxia is a shared risk across this entire drug class.⁹ Heroin is not uniquely dangerous in this respect, but its rapid onset means the respiratory depression also hits fast, leaving less time to intervene.

Tolerance, Dependence, and the Narrowing Window

With repeated use, the body adapts. Opioid tolerance develops as mu-opioid receptors become less responsive through a process called desensitisation, where the receptors effectively uncouple from the signalling machinery inside the cell.⁶ The user needs more drug to get the same effect, whether that effect is pain relief or euphoria. Tolerance to the rewarding effects develops faster than tolerance to the respiratory depression, which means the margin between a dose that feels good and a dose that stops breathing narrows over time. After a period of abstinence, tolerance drops rapidly, so a person who relapses and takes their old dose is at severe risk of overdose.

Physical dependence is distinct from tolerance but develops alongside it. A person who is physically dependent will experience withdrawal symptoms when the drug is removed, including severe muscle pain, nausea, insomnia, and intense drug craving. These symptoms are not life-threatening in the way that alcohol or benzodiazepine withdrawal can be, but they are profoundly unpleasant and drive continued use. The combination of tolerance, dependence, and the powerful reward signal from rapid-onset mu-opioid activation is what makes heroin one of the most addictive substances known.

Heroin-Assisted Treatment for Addiction

One of the more counterintuitive medical uses of heroin is prescribing it to people who are already addicted to it. Heroin-assisted treatment, sometimes called supervised injectable heroin or by its acronym HAT, provides pharmaceutical-grade diamorphine under clinical supervision to people with severe opioid dependence who have not responded to conventional treatments like methadone. The idea is not to cure the addiction immediately but to replace a chaotic, dangerous street habit with a stable, medically monitored one, reducing overdose risk, crime, and infectious disease transmission while giving the person a chance to stabilise their life.

Switzerland pioneered this approach in the 1990s after facing an acute heroin crisis, and it has since been adopted in varying forms in the Netherlands, Germany, Denmark, Spain, Canada, and the UK. The evidence supporting it is substantial. A systematic review and meta-analysis of randomised trials found that supervised injectable heroin led to greater reductions in illicit street heroin use and significantly better treatment retention compared with oral methadone, with a pooled relative risk for retention of about 1.37.¹⁰

The UK’s RIOTT trial, one of the largest individual studies, randomised patients with chronic heroin addiction to receive either supervised injectable heroin, supervised injectable methadone, or optimised oral methadone. At 26 weeks, about 72% of those receiving injectable heroin had achieved the primary outcome of substantially reduced street heroin use, compared with roughly 27% on oral methadone. The number needed to treat was just over two, meaning that for every two patients given injectable heroin instead of oral methadone, one additional patient stopped using street drugs.¹¹

Even in prison settings, HAT has shown promise. A retrospective study following 15 years of heroin-assisted treatment in a Swiss prison found that the programme could be delivered safely by prison health staff over extended periods, and that prisoners receiving HAT achieved work performance rates comparable to the general prison population.¹²

The Economics of Prescribing Heroin

HAT programmes are expensive to run. Patients typically attend a clinic twice daily to receive their injections under supervision, which requires dedicated medical staff, secure drug storage, and clinical space. The programme costs far exceed those of simply dispensing methadone tablets. But the economic picture changes dramatically when you look beyond the clinic walls.

A cost-utility analysis drawing on data from two randomised trials found that co-prescribing heroin with methadone was associated with a modest improvement in quality-adjusted life years and a mean net saving of roughly €12,800 per patient per year. The higher programme costs were more than offset by lower spending on law enforcement and reduced costs from criminal victimisation.¹³ A more recent UK analysis of co-located HAT within primary care found that healthcare utilisation costs dropped by 58% within six months of patients starting treatment, compared with the same period directly before.¹⁴ People who are not injecting contaminated street drugs, visiting emergency rooms, or cycling through the criminal justice system cost the system far less, even after accounting for the expense of providing pharmaceutical heroin in a supervised setting.

Safer Supply and the Fentanyl Crisis

The proliferation of illicit fentanyl and its analogues in the North American drug supply has pushed some jurisdictions to consider a broader version of the HAT concept. The “safer supply” approach involves prescribing pharmaceutical-grade opioids such as hydromorphone to people at high risk of fatal overdose, with the goal of displacing contaminated street drugs.¹⁵ The logic is straightforward: a person who uses a known drug at a known dose is far less likely to die than one injecting powder of uncertain composition from an unregulated source.

British Columbia introduced a Safer Opioid Supply policy that expanded access to prescribed opioids. An evaluation found that the policy led to significant increases in opioid prescriptions and the number of people filling them, but opioid-related poisoning hospitalisations also rose. Deaths from apparent opioid toxicity did not change significantly in either direction.¹⁶ These mixed results have made safer supply a politically contentious topic. Supporters argue the policy needs more time and broader implementation to show its full effect. Critics point to the rise in hospitalisations as evidence that diversion of prescribed opioids may be creating new harms.

A scoping review of the available evidence on prescribed safer opioid supply found generally positive indicators, including low rates of opioid toxicity among enrolled patients, improvements in physical and mental health, and better quality of life.¹⁷ The tension between individual-level benefits and population-level unintended consequences remains unresolved, and the evidence base is still young.

Where the Diamorphine Comes From

The legal supply chain for pharmaceutical diamorphine begins, as it does for illicit heroin, with poppy fields. Licensed growers cultivate Papaver somniferum, the opium poppy, which yields morphine, codeine, and thebaine among its alkaloids. Selective breeding has produced varieties with higher morphine content. As of 2020, about 91% of the world’s legal morphine-rich raw materials came from four countries: Spain, Turkey, Australia, and France. Spain alone produced about 141 metric tons, followed by Turkey and Australia at roughly 85 metric tons each.¹⁸

Morphine extracted from the raw plant material is then chemically acetylated to produce diamorphine. The manufacturing process is straightforward in chemical terms but tightly regulated under international narcotics conventions. Switzerland, which has run a national HAT programme since the mid-1990s, has relied on a single domestic manufacturer for its pharmaceutical diamorphine supply. This monopoly dependency has raised concerns about supply security and pricing. If that one manufacturer stops producing the drug or cannot meet demand, the entire treatment programme is at risk. The vulnerability illustrates a broader tension: the international drug control system keeps the legal production base for diamorphine deliberately small, which works well for limiting diversion but poorly for scaling up treatment programmes when clinical evidence supports them.

What Patients Say About Heroin-Assisted Treatment

Qualitative research with people who enrolled in injectable diacetylmorphine or hydromorphone programmes in Vancouver found that their motivations were shaped heavily by past negative experiences with other treatments, particularly methadone, and by immediate survival concerns. The presence of fentanyl in the street drug supply was a major driver: participants wanted to stop gambling with their lives every time they used. Poverty, criminalisation, and the desire for a pharmaceutical product whose strength they could trust all factored into the decision to seek out supervised treatment rather than continue buying from dealers. For many, the appeal was not just staying alive but regaining some control and predictability in a life defined by chaos.