While the opioid heroin is not as widely used as tobacco, marijuana, cocain, crack or ecstasy (among others), it was ranked the second most harmful drug overall. It is also considered the second most harmful in terms of harm to its users (#1 is Crack), as well as second in terms of harm to others (#1 is Alcohol).
Known also as smack, skag and skunk, heroin is can be used through injection, smoking or snorting, all of which result in a strong sense of euphoria, as well as impaired coordination, confusion, and sedation.
Consequences can of use can be severe as the risks involved are many, and potentially fatal. As well as an increased risk of contracting HIV and hepatitis, users also run the risk of endocarditis (the inflammation of the inner layer of the heart). Users can easily become addicted, and fatal overdoses are not uncommon.
The raw form of heroin, opium is extracted from the opium poppy, and when processed, becomes heroin. All the same risks and effects associated with heroin are also associated with opium.