Doctors are warning about a substance they call gas station heroin that is available over the counter at vape stores across Arizona. The product is called 7 OH, a component derived from kratom. FDA Pushes to Classify 7 OH Sold in Vape Shops as Illicit Drug Ecigator STACK'D Pure 7 Hydroxymitragynine Disposable Vape 2g Full Case (8ct) 7OH Resellers 7 OH kratom is fueling addictions across the Philly region