glutathione usp L-Glutathione Powder May be used at 5 L-Glutathione Reduced - Bulk Supply

Enhances Skin Radiance & Texture Helps support smoother, softer and fresh-looking skin while promoting a naturally healthy glow

doi: 10.1016/j.bbagen.2009.03.015 86 GandinVKhalkarPBraudeJFernandesAP

Thats probably because you cant go to your health food store and buy glutathione in a bottle

The chemical mechanism by which glutathione -S- transferase is inactivated by the glutathione acrylate analog is likely based on the presence in the tertiary structure of the enzyme of a docking site where glutathione is bound and its free thiol group is deprotonated by a facing amino acid which acts as a strong proton acceptor [129]