l-leucine

L-leucine is the biologically active, naturally occurring enantiomer of leucine, an essential branched-chain amino acid (BCAA) with the molecular formula C6H13NO2. It is a non-polar, aliphatic amino acid characterized by an isobutyl side chain and plays a critical role in protein biosynthesis and muscle metabolism. As one of the three BCAAs, l-leucine cannot be synthesized by humans and must be obtained from dietary sources such as meat, dairy products, soy products, and legumes[2][3][6]. Its primary mechanism of action involves direct stimulation of myofibrillar muscle protein synthesis through activation of the mechanistic target of rapamycin (mTOR) pathway[2][5]. This effect makes it vital for muscle growth, repair, maintenance, and recovery. Additionally, l-leucine has been investigated for therapeutic use in conditions like sarcopenia and cachexia due to its anabolic effects on skeletal muscle[5]. It is widely used as a dietary supplement in sports nutrition.

Brand names

Aminosyn II 7 % Sulfite-freeAminosyn-PF 7%Clinimix 2.75/5Clinimix E 2.75/5Clinisol 15Clinisol15Clinisol-15Freamine 6.9Freamine6.9Freamine-6.9Freamine III 10Hepatamine 8Hepatamine8Hepatamine-8NephramineOlimelPeriolimelPlenaminePremasolPrimeneProcalamine 3Procalamine3Procalamine-3ProsolTravasol 10Travasol10Travasol-10Trophamine 10 %

Other names

leucineLeucinH-Leu-OH2-Amino-4-methylpentanoic acid4-methyl-norvalinL-Leu-OHLeucinum