Pharmaceutical grade heroin is called diacetylmorphine or diamorphine. ‘Heroin’ refers to the illicit type, originating from the Golden Triangle (Thailand, Laos and Myanmar) and is usually (off) white. Most of the heroin available in the UK comes from The Golden Crescent (Afghanistan, Iran and Pakistan), and is a base form of the drug (an intermediary stage in the production process to the salt form). This makes it suitable for smoking, and much illicit heroin is smoked on tin-foil (‘chasing the dragon’ or ‘booting’).

The salt form of diamorphine/heroin is very soluble, and the base, (usually a brown powder) can also be injected, but requires an acidifier and heat to make it dissolve (citric acid or vitamin C typically).  For more advice, including harm reduction, see our safer injecting section here.

The drug acts on a series of receptors in the brain, gut and spinal column, inducing feelings of well-being and calm.  

Heroin crosses the blood-brain barrier extremely effectively.  Once in the brain, it is broken down and to morphine, which bind to receptors, resulting in the drug's euphoric, anxiolytic (reducing anxiety) and pain killing effects