Chinese vape manufacturers are selling products in the United States containing nicotine-like chemicals that may fall outside federal tobacco rules. The practice appears to exploit gaps left after Congress tightened regulation of synthetic nicotine, raising concerns because these compounds have received little human-safety research and may be more addictive than nicotine.

One commonly used analogue, 6-methyl-nicotine, was found in animal studies to be potentially more potent and addictive than nicotine. Researchers first identified such products in the US about three years ago, while a 2024 study found some analogue vapes also contained unlabelled sweeteners and cooling agents with uncertain inhalation risks. Tobacco firms had investigated similar compounds from the 1970s, but Chinese disposable-vape makers have brought them to the mass market amid enforcement efforts against flavoured nicotine vapes.