L Carnitine Erectile Dysfunction: What the Evidence Actually Shows What is the recommended duration of carnitine (L carnitine) supplementation? L Carnitine Linus Pauling Institute Oregon State University Top 7 L Carnitine L Tartrate Uses for Fat Loss 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