Does L Carnitine Work for Weight Loss? What the Science Says How to Take L Carnitine Correctly to Boost Your Training Bodybuilding.com L Carnitine isn't magic but it can be a powerful tool when your training and nutrition are already dialed in Here's why I like it Supports fat metabolism L Carnitine helps 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