D-Aspartic acid-b-methyl ester hydrochloride is primarily used in biochemical research and pharmaceutical development. It serves as a key intermediate in the synthesis of peptides and other bioactive molecules. Researchers utilize it to study enzyme mechanisms and protein interactions due to its structural similarity to natural amino acids. Additionally, it is employed in the development of drugs targeting neurological disorders, as it can influence neurotransmitter activity. Its role in modulating hormonal pathways, particularly testosterone production, has also been explored in studies related to hormonal therapies and performance enhancement.