L carnitine's acts as a fat burning supplement. During bulking periods, it can help limit fat gains and make a cleaner bulk. If you're cutting, it can help transport the fat you have into L carnitines acts as a fat burning supplement. During bulking periods, it can help limit fat gains and make a cleaner bulk. If youre cutting, it can help transport the fat you have into your Amazon.com: BulkSupplements.com L Carnitine Tartrate Powder Amino Acid Powder, Carnitine Supplement Unflavored & Gluten Free, 1g per Serving, 100g (3.5 oz) (Pack of 1) : Health & Household L Carnitine LKT Labs RECOVERY AMINOS!!!!!!!! So typically I would drink this starting right before my workout and during the whole session, something's I have taken notice of, I can train longer and harder, definitely hydrates Lean Muscle vs. Bulk Muscle: Which Approach is Right for You?