Amazon.com: Jacked Factory Growth Surge Creatine Post Workout w L Carnitine Daily Muscle Builder & Recovery Supplement with Creatine Monohydrate, Betaine, L Carnitine L Tartrate 30 Servings, Cherry Limeade : Everything Else Understanding the Benefits and Uses of Carnitine in Health and Fitness Fitness Health Early research into L carnitine was often cited as underwhelming, showing negligible changes in muscle carnitine content and fat loss outcomes. However, these findings may have been limited by a short study window L Carnitine Benefits, Uses, Dosage, Foods, Side Effects Dr. Axe