Please clarify the difference between Glutathione and reduced Glutathione.

Substances such as vitamin C, vitamin E, and alpha lipoic acid, in the oxidized state (missing electrons) no longer function as antioxidants. Only when they are reduced (contain needed electrons) can they effectively function as antioxidants. This means that Glutathione must be reduced in order to function as an antioxidant and attack free radicals.