Fmoc-L-Glu(NMe)-OH, or (S)-2-((((9H-Fluoren-9-yl)methoxy)carbonyl)amino)-5-(methylamino)-5-oxopentanoic acid, is a protected amino acid derivative used as a building block in solid-phase peptide synthesis (SPPS). The Fmoc group provides temporary Nα-protection, which is orthogonally removed under mild basic conditions (e.g., 20% piperidine in DMF), enabling stepwise chain elongation without affecting other protecting groups. The free α-carboxylic acid participates in coupling reactions to form peptide bonds with the growing chain or resin. The glutamic acid side chain is modified as a γ-N-methylamide, which is inert under SPPS conditions and introduces a specific amide functionality, useful for peptides requiring C-terminal-like modifications or enhanced stability. The (S)-configuration ensures retention of L-chirality, critical for biological activity. This reagent is essential in pharmaceutical R&D for producing therapeutic peptides, peptide conjugates, and research probes demanding high purity and stereochemical integrity.