Although full-scale substance control was started 60 years ago in accordance with the international treaty, only in recent years have the harmful effects of such a heavy-penalty policy begun to be recognized. Harm reduction (HR) is a public health policy that aims to complementarily reduce the amount of drug consumption by reducing both the supply of and demand for drugs.
 This report outlines the process of the international society adopting the HR policy, its practice, and its outcome. The author argues that HR was not the "last resort" in countries with severe drug abuse, but rather an effective public health policy and a principle of support provision that goes beyond the limitations of the heavy-penalty policy. Furthermore, the author emphasizes that HR was an ethical practice to respect the human rights of drug users and save them from isolation after being alienated from treatment and support due to the heavy-penalty policy.
 Lastly, the author claims that the countermeasures for new psychoactive substances (NPS), which overemphasize supply reduction and virtually neglect demand reduction, allowed the spread of the dangerous NPS and may increase harm due to NPS use. Furthermore, regarding methamphetamine, which has been among the most seriously abused drugs in Japan, the HR policy was suggested to provide a safe environment for medical treatment and raise awareness for drug abuse prevention without exacerbating the self-stigma of drug users.
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