D-Cysteine

D-Cysteine, the D-isomer of cysteine, is an orally active antibacterial agent and a regulator of neural progenitor cell proliferation. D-Cysteine can inhibit Escherichia coli, Streptococcus mutans, and Streptococcus sanguinis. The no-observed-adverse-effect level of D-Cysteine in rats should be less than 500 mg/kg/day[1][2][3][4].