L Carnitine supplement for horses and dogs L Carnitine is amino acid supplement that enhances energy production in performance horses. It works through 6 ways: Muscle level of L Carnitine influence the exercise capacity of a horse. L L Carnitine Therapy Valhalla Vitality Spring Valley Acetyl L Carnitine HCI 400 mg + Alpha Lipoic Acid 200 mg Capsules, 50 Count HSA FSA Eligible Walmart.com Structure of L carnitine and acetyl L carnitine. Download Scientific Diagram