Restricting the supply of an illegal drug can make the drug more expensive. Many users of heroin are forced into criminal activities such as theft and prostitution in order to obtain sufficient money to support their drug use. Because some drugs are illegal, they are not subject to any form of quality control. Drugs bought on the street are of unknown strength, which increases the risk of accidental overdose. Whilst there is always a chance of overdose, this can be of particular risk to the one-off, inexperienced or occasional user.
Street drugs can contain other unwanted or dangerous chemicals causing illness or death.
The Federal Customs Act covers the importing of drugs while each state has laws governing the manufacture, possession, distribution and use of drugs, both legal and illegal. Drug laws in Australia distinguish between those who use drugs and those who supply or traffic drugs. Victoria Police recently introduced a cannabis cautionary scheme for those caught using cannabis for the first time. Under this scheme first time offenders are formally cautioned by police then referred to a drug treatment centre. Police have also begun trialling a cautionary scheme for heroin and other illicit drugs.