Z-DL-His-OH is primarily used in peptide synthesis as a protected form of histidine. It serves as a building block in the production of complex peptides and proteins, ensuring the histidine residue remains stable during chemical reactions. This compound is particularly valuable in pharmaceutical research for developing peptide-based drugs, where histidine plays a critical role in biological activity. Additionally, it is utilized in biochemical studies to investigate enzyme mechanisms and protein interactions, as histidine is often involved in catalytic sites. Its application extends to the synthesis of custom peptides for diagnostic tools and therapeutic agents, contributing to advancements in medicine and biotechnology.