Didn't another study show carnitine was good for the heart? The Role of L Carnitine in Kidney Disease and Related Metabolic Dysfunctions Amazon.com: Life Extension Optimized Carnitine, Three Forms of L carnitine, Promotes Heart & Brain Health, Gluten Free, Non GMO, Vegetarian, 60 Capsules : Health & Household Benefits of L carnitine injections are aplenty! This injection is a great way to boost your energy levels, help with weight management, and even promote healthy heart function. Studies show that Health Benefits Carnitine Infographic Including Deficiency Stock Vector (Royalty Free) 364114724 Shutterstock L Carnitine is Underrated. New Meta Review Reminds Us Why.