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 is Underrated. New Meta Review Reminds Us Why. Extreme Mid Afternoon Fatigue? Here's What I Tried to Beat It 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.,