L Carnitine 3500 Metabolic Nutrition If you are like a lot of people, you may have never heard of carnitine but this important nutrient is critical for our body's ability to optimally burn fat required for energy. L Carnitine 3500 Metabolic Nutrition Amazon.com: Nutrex Research L Carnitine 3000 Clinically Dosed L Carnitine Liquid for Energy, Metabolism & Muscle Recovery Delicious Sour Gummy Worms Flavour No Sugar, No Carbs, No Stimulants 31 NOW Foods L Carnitine, Triple Strength Liquid 16 fl. oz.