A little-known class of synthetic opioids, nitazenes, is spreading rapidly across the Americas, causing a surge in overdose deaths. These drugs, more potent than fentanyl, evade standard drug tests and require specialized detection methods. Experts warn of the growing trend and the challenges in combating their proliferation. Nitazenes, originally developed as pain relievers in the 1950s but never approved for use due to high overdose risks, have entered the illicit drug market since 2019. They are being produced in illicit labs in places like China and India and trafficked into the U.S. through the same channels as fentanyl. The most prevalent type is isotonitazene (ISO), which the DEA classifies as a Schedule 1 drug. Nitazenes are available in various forms, including pills, powders, sprays, and can be snorted, smoked, injected, or taken orally. Their potency, which can be up to 10 times stronger than fentanyl, makes even small doses deadly. The drugs are often mixed into other substances like heroin or stimulants, increasing the risk of unexpected overdoses. Testing for nitazenes is limited, with only specialized labs able to detect them. Experts emphasize the need for rapid drug-checking tools and widespread distribution of naloxone to address the crisis.