Effect of a 3 month L carnitine supplementation and resistance training program on circulating markers and bone mineral density in postmenopausal women: a randomized controlled trial Nutrition & Metabolism Springer Nature Link 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 L Tartrate: 8 Key Benefits Dr. Lam Addlife Blog I 5 Key Benefits of L Carnitine