N-Methyldiethanolamine-d3 Hydrochloride is isotopically labelled salt form of N-Methyldiethanolamine (M301625), which is used as a reagent in the synthesis of broad-spectrum antimicrobial polycarbonate hydrogels with fast degradability. It is also used as a reagent in the synthesis of dihydroxy quaternary ammonium salts with long chain alkyl bromides that can exhibit antibacterial and antifungal activity.