L Carnitine: 3 Ways Physique Pros Use This Fat to Fuel Powerhouse SteelFit USA Supplements don't replace the workbut they can support it L Carnitine helps your body turn fat into usable energy, so you can push harder and recover better. Consistency first. Supplements second. Results Parker Naturals Concentrated L Carnitine Liquid, 5000mg All Natural Citrus Flavored L Carnitine Supplement, Liquid L Carnitine with Vitamin V5, 16.23 JYM L Carnitine L Tartrate