Heroin-assisted treatment (HAT), or diamorphine-assisted treatment, refers to a type of Medication-Assisted Treatment (MAT)[1] where semi-synthetic heroin is prescribed to opioid addicts who do not benefit from, or cannot tolerate, treatment with one of the established drugs used in opioid replacement therapy such as methadone or buprenorphine/nalxone (brand name Suboxone). For this group of patients, heroin-assisted treatment has proven superior in improving their social and health situation.[2] Heroin-assisted treatment is fully a part of the national health system in Switzerland, Germany, the Netherlands, Canada,[3] and Denmark.[4] Additional trials are being carried out in the United Kingdom,[5] Norway,[6] and Belgium.[7]