The Personal Health Zone reports that one ingredient of Lipo-6, yohimbine, is toxic and should be avoided. It can cause anxiety attacks, renal failure, seizures and death. WebMD declares that taking the combination of caffeine and synephrine, which are ingredients found in Lipo 6, is potentially unsafe.
According to its manufacturer, Nutrex, Lipo-6 contains: caffeine, synephrine, yohimbine, bioperine and guggul. WebMD reports that synephrine, also called bitter orange, is banned by the National Collegiate Athletic Association: When combined with caffeine, it can cause high blood pressure and increased heart rate, fainting, heart attacks and stroke. According to European Revolution, some users of Lipo-6 have reported serious side effects.