Many of the health dangers associated with recreational drugs exist or are made worse precisely because they are illegal. The government cannot enforce quality control on products sold and manufactured illegally. Examples include: the easier to make derivative MDA being sold as MDMA, heroin users unintentionally injecting brick dust, quinine, or fentanyl with which their heroin had been cut; and heroin/cocaine overdoses occurring as a result of users not knowing exactly how much they are taking.
The illegality of injectable drugs leads to a scarcity of needles which causes an increase in HIV infections. An easy cure to this problem, while upholding the illegality of drugs, is the Dutch policy of distributing free needles. The money spent on both increased health costs due to HIV infections and drug prohibition itself causes a drain upon society.
Studies on the effects of prescribing heroin to addicts as practised in many European countries have shown better rates of success than any other available treatment in terms of assisting long-term users establish stable, crime-free lives. Many patients were able to find employment, some even started a family after years of homelessness and delinquency.