Can L Carnitine Improve Fat Loss? Uncle Gym's Advice Oxyenergys L Carnitine. My go to pre post workout supplement. Pre workout I usually take it before my workout session for energy production. Post workout Ill take it the day after my workout L Carnitine helps your body turn fat into fuel improving energy, endurance, and recovery. Combine it with consistent training and a clean diet for real results! , ., ., ., ., #LCarnitine #FatLoss How to Take L Carnitine Correctly to Boost Your Training Bodybuilding.com