Heroin can be smoked, dissolved in water and injected or, if high purity, it can be snorted. Intravenous injection (directly into the veins) provides the greatest intensity of euphoria, while intramuscular injection (directly into the muscle) produces a relatively slow onset of euphoria (5 to 8 minutes). Typically a heroin injector may inject up to four times a day. When heroin is smoked, effects are felt within seconds. All three forms of heroin administration are addictive.
The tools typically used to inject heroin include a syringe with needle, spoon, lighter, cigarette filter, belt, citric acid (typically lemon juice) and water.
The heroin is put onto the spoon with citric acid, the right amount of water and citric acid will then be mixed with the heroin (the citric acid is used to breakdown the Heroin so it can be injected). At the same time the spoon is held over the heat source so all the three substances are mixed together. Once mixed, a cigarette filter will be placed onto the spoon; the solution will then be drawn up the syringe through the filter to filter out any impurities. It is now ready to be injected into a vein usually in the arm. The belt or similar implement such as a shoe lace is tied tightly around the arm to stop the blood flow; this will cause the veins to stand out for easier injection. After long periods of use the veins will become damaged and other areas of the body are used for injecting into. Other places used are in the groin area, behind the knees or in serious cases in the neck.
Injecting is a common route of administration among heroin users, although less common than smoking. Additives in street heroin may not dissolve readily and as a result, injecting heroin can contribute to the clogging of the blood vessels that lead to the lungs, liver, kidneys, and brain. Collapsed veins, cellulitis, and abscesses are common problems among chronic injecting heroin users.