Iran has developed chemical weapons based on synthetic opioids such as fentanyl, warns a US expert, powerful agents that could incapacitate soldiers or civilians when added to grenades or artillery.

Our fortnightly column also highlights attacks on the LGBT community in Russia, fentanyl production in Mexico, and a New York Times analysis of its own past travel recommendations.

Background: Fentanyl, a short-acting synthetic opioid, has a pharmacokinetic profile suited to fast relief of brief episodic pain. Objective: To characterize the pharmacokinetic-pharmacodynamic ...