L-cysteine is a conditionally essential amino acid, one of onlythree sulfur-containing amino acids, the others being taurine (whichcan be produced from L-cysteine) and L-methionine from which L-cysteinecan be produced in the body by a multi-step process. Cysteine playsa role in the sulfation cycle, acting as a sulfur donor in phase IIdetoxification and as a methyl donor in the conversion of homocysteineto methionine. Cysteine also helps synthesize glutathione, one of thebodys most important natural detoxifiers. N-acetyl-cysteineis the acetylated form of L-cysteine, which is more efficiently absorbedand used.54-64

Glutathione (gamma-L-glutamyl-L-cysteinyl-glycine) is a peptide(short protein)-like molecule synthesized in the body from thethree amino acids L-glutamic acid, L-cysteine, and glycine. Glutathioneis one of the bodys most important and powerful antioxidants,helping to detoxify xenobiotics. A major function of vitamin Cis to keep glutathione in its reduced form so that they can continueto provide free radical quenching effects.65-68

Even though many published studies show that garlic, selenium,alpha-lipoic acid, L-cysteine, and N-acetyl-cysteine can boostcellular glutathione levels, people with health problems may benefitfrom taking high doses of glutathione.65,69-71*

The liver is a large glandular organ, whose functions include storageand filtration of blood, secretion of bile, detoxification of varioussubstances, and conversion of sugars into glycogen, which it stores.The liver is also responsible for processing many vitamins and nutrientsinto a form that can be utilized by the body, and processing many toxicchemicals for elimination.

Modern living involves daily exposure to substances that are toxicto our bodies, which imposes a heavy load on the liver. Therefore, ahealthy liver is critical to well-being. Certain lifestyle risks andmedical conditions make it all the more important to ensure that theliver is being maintained at its functional best.

In Europe and Asia, herbal liver tonics have been in common use forcenturies. The effectiveness of the herbs used has been validated duringthe past decades through modern research and clinical studies. Theseherbs generally contain antioxidants, cell membrane stabilizing agents,bile secretion enhancing compounds, or nutrients that prevent depletionof endogenous antioxidants such as glutathione. Hepato-protection isbeneficial not only for the liver, but for the overall health and vitalityof our body.

N-acetyl cysteine is the more efficiently absorbed and used form ofthe amino acid, L-cysteine. L-cysteine plays a role in the sulfationcycle, acting as a sulfur donor in phase II detoxification and as amethyl donor in the conversion of homocysteine to methionine. N-acetylcysteine has antioxidant properties, and helps to maintain healthy levelsof the livers natural detoxifier, glutathione. In addition, N-acetylcysteine has been used to break up pulmonary and bronchial mucus.53-63*

When taking L-cysteine, N-acetyl-cysteine, or glutathione, it is recommendedthat three times as much vitamin C should be taken at the same time toprevent these amino acids from being oxidized in the body.*