Neither L Carnitine nor Berberine work like caffeine, yohimbine, or fat burners. They do NOT: Spike your heart rate Jack up your nervous system Cause jitters or crashes Mask Best Way To Take L Carnitine & Its Uses Plix iSatori L Carnitine LS3 3000, Liquid L Carnitine with Acetyl L Carnitine, L Carnitine L Tartrate, Stimulant Free Pre Workout Taking a preworkout AND carnitine? It is important to get the timing of each supplement right to get the best results with both. Watch as Phil explains the best way to combine them. , #preworkout