H-Sar-OMe (sarcosine methyl ester) is a derivative of the non-proteinogenic amino acid sarcosine (N-methylglycine). It serves as a key building block in solid-phase peptide synthesis (SPPS), often incorporated as a C-terminal ester or N-terminal capping agent. The N-methyl group imparts desirable properties such as increased proteolytic resistance, enhanced lipophilicity, and conformational constraints, making it ideal for designing stable therapeutic peptides, peptidomimetics, and bioactive compounds in medicinal chemistry research.