Ingredient Spotlight: L Carnitine Source: Biosynthesised in the body from the amino acids Lysine and Methionine, L Carnitine is a conditionally essential nutrient involved in energy metabolism and fat transport. Key Benefits Top 5 Benefits of CoQ10 and L Carnitine Combination for Athletes iThrive Essentials L Carnitine Benefits: A Complete Research Based Guide L Carnitine vs L Arginine: Understanding Their Differences and Benefit Fitness Health There's a reason L carnitine keeps showing up in PCOS research Because PCOS is closely tied to insulin resistance, inflammation, and metabolic dysfunctionand L carnitine plays a role in energy metabolism and fat utilization.