Fmoc-Gly-OH is widely used in peptide synthesis as a building block for constructing peptides. It serves as a protected form of glycine, where the Fmoc (fluorenylmethyloxycarbonyl) group acts as a temporary protecting group for the amino group during solid-phase peptide synthesis (SPPS). This allows for the sequential addition of amino acids to grow the peptide chain. After each coupling step, the Fmoc group can be easily removed using a mild base, such as piperidine, without disturbing the peptide backbone. Its application is critical in the production of therapeutic peptides, research peptides, and other biologically active compounds. Additionally, it is used in the development of peptide-based drugs, vaccines, and diagnostic tools due to its reliability and efficiency in peptide assembly.