L Carnitine 3000, Peach Mango, 16 fl oz (473 ml) L Carnitine Liquid: Benefits, Dosage & How It Works Biotell UK Yes, L Carnitine works best once you take it before exercising and when you have calories to burn., But, it works just as well when you take it before sleeping., Get yours now! , L Carnitine Liquid Benefits of L Carnitine:, When taken as a supplement, L Carnitine has been shown to have a beneficial impact on weight loss and improved brain function. It has also been linked to improved heart