US health authorities warn of cyclorfine, a synthetic opioid 10x fentanyl potency

US health authorities warn about cyclorfine, a synthetic opioid linked to fatal overdoses that is 10 times more potent than fentanyl and 1,000 times more than morphine. Routine toxicology tests may not detect it, complicating overdose response and surveillance. The emergence of a new ultra-potent opioid in the illicit drug supply raises public health and law enforcement concerns.