Fmoc-octyl-D-Gly-OH is widely used in peptide synthesis as a building block for introducing hydrophobic alkyl chains into peptide sequences. Its Fmoc protecting group allows for selective deprotection during solid-phase peptide synthesis, enabling the stepwise construction of complex peptides. The octyl group enhances the lipophilicity of the peptide, making it useful in studies involving membrane interactions, such as the development of antimicrobial peptides or cell-penetrating peptides. Additionally, it is employed in the design of peptide-based drug delivery systems, where increased hydrophobicity can improve drug encapsulation and targeting efficiency. Its D-configuration provides resistance to enzymatic degradation, making it valuable in creating stable peptide analogs for therapeutic applications.