Explainer: nitazenes and xylazine – a cause for concern

Historically, most of the heroin in the UK came from Afghanistan. However, in 2022, the Taliban banned poppy cultivation and after December 2023 it became illegal to export heroin from Afghanistan.

At the same time, an increasing quantity of synthetic drugs such as nitazenes and xylazine have been detected in the illicit drug market both internationally and in the UK and it is feared that a recent spike in related deaths could indicate a much larger problem than estimates currently suggest.

‘These synthetics are quite cheap, and they’re very strong, which means that you only have to ship a small amount that you can then dilute at destination to make up a lot of doses,’ explains Caroline Copeland, an expert in pharmacology and toxicology and director of the National Programme on Substance Abuse Deaths at King’s College London.

But what exactly are these compounds, where have they come from and how do they cause harm?