L Carnitine Benefits, Uses, Dosage, Foods, Side Effects Dr. Axe 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 Taking L carnitine, will it improve endurance and recovery? L Carnitine Injection Levocarnitine IV L Carnitine Linus Pauling Institute Oregon State University According to a study published in Clinical Therapeutics, in people with type 2 diabetes and high cholesterol, taking L carnitine (1 gram twice daily) for 6 months significantly lowered lipoprotein(a) a genetic,