D-citrulline is used in peptide synthesis drug discovery enzyme studies and protein engineering research to investigate structureactivity relationships and to develop peptides with enhanced resistance to enzymatic degradation.

The primary purpose of D-citrulline is to serve as a specialized amino acid building block in biochemical pharmaceutical and peptide research where the incorporation of D-amino acids can modify biological activity and stability.

D-Citrulline is the D-isomer of citrulline a non-proteinogenic amino acid that contains a ureido functional group and differs in stereochemistry from the naturally occurring L-citrulline.