L-Glutathione is one of the body’s most important and powerful antioxidants. A major function of vitamin C is to keep L-glutathione, L-cysteine, and N-acetyl-cysteine in reduced form so that they can continue to have their powerful free radical quenching effects. L-Glutathione (gamma-L-glutamyl-L-cysteinyl-glycine) is a peptide (short protein)-like molecule synthesized in the body from the three amino acids L-glutamic acid, L-cysteine, and glycine.
L-cysteine is a conditionally essential amino acid, one of only three sulfur-containing amino acids, the others being taurine (which can be produced from L-cysteine) and L-methionine from which L-cysteine can be produced in the body by a multi-step process. L-cysteine can act as an antioxidant, may prevent liver diseases, and can help to thicken the individual diameters of existing hair if taken regularly.
N-acetyl-cysteine is the acetylated form of L-cysteine which is more efficiently absorbed and used. It is also an antioxidant that is helpful against viruses. N-acetyl-cysteine has been used as a liver protectant and to break up pulmonary and bronchial mucus. N-acetyl-cysteine can boost glutathione levels in cells.
Even though many published studies show that garlic, selenium, alpha-lipoic acid, L-cysteine and N-acetyl-cysteine can boost cellular glutathione levels, people with health problems may benefit from taking high doses of glutamine. Those with cataracts or liver disease may want to take 500 mg a day of this very potent antioxidant.
When taking L-cysteine, N-acetyl-cysteine, or glutathione, it is recommended that three times as much vitamin C should be taken at the same time to prevent these amino acids from being oxidized in the body.