L Carnitine injection is recommended at 1 ampule every 2 3 days for best results. The L Carnitine is taken intravenously either by normal injection or using a butterfly needle. After taking this L Carnitine, you Did You Know? Some people report a fishy smell after supplementing with L carnitine. This happens because certain gut bacteria convert carnitine to trimethylamine, a malodorous compound found in rotting fish. Does L carnitine cause fishy body odor? Surprising Truth and Solutions Tonum L Carnitine 3000 Liquid 3000 mg Carnitine Supplement Zero Calorie Zero Sugar Keto Friendly for Men and Women Great Tasting 31 Servings (Patriot Pop, 16 fl. oz Walmart.com Amazon.com: Ronnie Coleman Signature Series L Carnitine XS 3000 Liquid, Amino Acids Metabolism and Lean Muscle Strength Support, Stimulant Free, Sugar Free, Zero Carbs, Orange Smash, 16 Oz : Health & Household