The economic collapse exacerbated by U.S. sanctions has significantly affected Iranian drug markets, as seen in the prices of most substances which have increased steadily, and practitioners now report a renewed wave of injecting drug use in open-air drug markets across urban areas. Meanwhile, the currency’s fall has likely contributed to the displacement of methamphetamine production to Afghanistan, leading in turn to an influx of cheap Afghan methamphetamine which will have major consequences for Iranian public health and the criminal justice system. The consequences of economic collapse have been devastating for already vulnerable and marginalised drug users and will likely lead to more widespread use-related disorders. Unless drug treatment and harm reduction are strengthened and international support given, particularly to Iranian NGOs active in providing life-saving services, drug-related harms will increase.