L Carnitine L Tartrate: 8 Key Benefits Dr. Lam How Much L Carnitine Per Day: Expert Guide The Science of Good 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 Systemic regulation of L carnitine in nutritional metabolism in zebrafish, Danio rerio Scientific Reports