Jabba SV, et al. - In view of the possibility for exemption of mint- and menthol-flavored e-cigarettes from proposed federal regulations, researchers focussed on the health risk associated with pulegone in these products. Oral administration of pulegone, a constituent of oil extracts prepared from mint plants, including peppermint, spearmint, and pennyroyal, caused hepatic carcinomas, pulmonary metaplasia, and other neoplasms in rodents. Synthetic pulegone as a food additive was banned in 2018 by the US FDA. As per studies by the Centers for Disease Control and Prevention, mint- and menthol-flavored e-cigarette liquids and smokeless tobacco products marketed in the United States have substantial amounts of pulegone. Because of toxicity concerns, the tobacco industry has minimized pulegone levels in cigarette flavorings.