L Carnitine Benefits, Uses, Dosage, Foods, Side Effects Dr. Axe What is L carnitine? Reducing fatigue Life Extension Europe Did you know L carnitine, a vital amino acid, is naturally produced by your body and found in various foods? While acetyl L carnitine (ALCAR) can be a beneficial supplement for some, most people get L Carnitine has become one of the most commonly asked about supplements over the past 18 months and I can see why when looking at all the research that has come out about it over the last 2ish years., What is L carnitine? Reducing fatigue Life Extension Europe L Carnitine Linus Pauling Institute Oregon State University