Prescribing heroin to heroin addicts is a strategy beloved by top police officers1 and successive home secretaries.2 It is a strategy, though, borne of utter frustration at our seeming inability to tackle an escalating drug problem. If you cannot stop addicts committing crimes to fund their drug habit then, so the argument goes, the next best thing is to provide them with the drugs that are the reason they are committing the crimes in the first place. The logic may seem faultless, but at the back of your mind is the nagging question, “Is it treatment or is it social problem prescribing?”