L-4-Hydroxyproline methyl ester hydrochloride is widely used in the synthesis of peptides and proteins, particularly in the production of collagen-like structures. It serves as a crucial building block in the development of biomaterials for tissue engineering, aiding in the creation of scaffolds that mimic natural extracellular matrices. This compound is also employed in pharmaceutical research for the design of drugs targeting connective tissue disorders, such as fibrosis and osteoarthritis. Additionally, it plays a role in cosmetic formulations, where it helps enhance skin elasticity and hydration by promoting collagen synthesis. Its application extends to biochemical studies, where it is used to investigate the role of hydroxyproline in protein stability and function.