L-Leucine (vegan fermented)

L-Leucine. Amino acids are building blocks of protein. The branched-chain amino acids (BCAAs, which include valine, isoleucine, and leucine) are nutritionally essential from food in the diet, because they are not synthesized in the human body 1. The EARs, or Estimated Average Requirements are 34, 15, and 19 mg/kg/day for leucine, isoleucine, and valine, respectively 1, 2. Dietary protein sources of these branched-chain amino acids include protein foods, such as dairy products, meat and legumes 3, 4. Athletes use BCAAs as they may support the body’s energy production, may reduce fatigue, and may improve concentration and performance, or help with recovery from workouts 3, 5, 6. In fact, Gleeson (2005) states that “few drinks containing significant amounts of BCAAs are commercially available” 5. Leucine has a part in many metabolic processes 4, 7. Some data supports that leucine plays a role in muscle protein synthesis, or building muscle mass 4, 3, 8. According 21CFR172.320, Amino acids, which includes the branched chain amino acids, such as L-Leucine, may be safely used as nutrients added to foods 9, 10.

This ingredient can be found in the following products in United States:


  1. Institute of Medicine (IOM). Food and Nutrition Board (FNB). Nutrition and traumatic brain injury: Improving acute and subacute health outcomes in military personnel. 2011. The National Academies of Sciences. Washington, DC: The National Academies Press.
  2. Institute of Medicine (IOM). Food and Nutrition Board (FNB). Dietary Reference Intakes (DRIs) for energy, carbohydrate, fiber, fat, fatty acids, cholesterol, protein, and amino acids (macronutrients). Washington, DC: National Academy Press, 2005; 589-738. Chapter 10. Protein and Amino acids.
  3. Natural Medicines database. Professional monograph. Branched-Chain Amino Acids Product ID 1005. Last reviewed 8/31/2018. Last updated 3/29/2019. Subscription required.,-herbs-supplements/professional.aspx?productid=1005
  4. Layman DK. The role of leucine in weight loss diets and glucose homeostasis. J Nutr 2003;(1):261S-267S. or
  5. Gleeson M. Interrelationship between physical activity and branched-chain amino acids. The 4th Amino Acid Assessment Workshop. J Nutr 2005; 135;1591S-1595S. or
  6. Blomstrand E. A role for branched-chain amino acids in reducing central fatigue. Branched-chain amino acids in exercise. J Nutr 2006;136:544S-547S. or
  7. Norton LE, Layman DK. Leucine regulates translation initiation of protein synthesis in skeletal muscle after exercise. Branched-chain amino acids in exercise. J Nutr 2006;136:S533-S537. or
  8. U. S. Department of Health and Human Services (DHHS). National Institutes of Health (NIH). Office of Dietary Supplements (ODS). Dietary supplements for exercise and athletic performance. Updated 6/30/2017.
  9. U. S. Food and Drug Administration (FDA). 21CFR172.320. Amino acids. Last updated 9/04/2018.
  10. U. S. Food and Drug Administration (FDA). 21 e-CFR172.320. Amino acids. Current as of 4/16/2019. Last