Cysteine is an important sulfur-containing nonessential amino acid important to many metabolic (biochemical) pathways. Dietary sources of this nutrient include poultry, yogurt, oats, and wheat germ, and in sulfur-containing foods such as egg yolks, garlic, onions, and broccoli.
Cysteine is a powerful antioxidant and detoxifier as a precursor (a substance that precedes another) for glutathione enzymes, which the body, and especially the liver, use for disabling destructive free radicals.
Key uses of cysteine include:
Practitioners recommend this amino acid for protection from chemical toxicity and to support the detoxification process in smokers and people exposed to chemicals or air pollution.
Cysteine helps prevent cataracts and cancer and aids in anti-aging programs.
Cysteine is important in your liver’s daily rebuilding process.
Researchers and clinicians are studying N-acetylcysteine (NAC), a special form of cysteine, for its ability to deliver cysteine into the lungs, where it acts as a powerful antioxidant to help protect lungs from the free radicals that scientists say can lead to worsening symptoms of lung diseases like emphysema. NAC is an excellent expectorant that helps keep the lungs clear of mucus.
Aspirin, acetaminophen (the active ingredient of Tylenol), and a host of other pain-relieving medications may irritate your liver. Ask your health practitioner about taking extra cysteine or NAC to help your liver protect itself from these potent chemicals. If your health practitioner deems it safe for you, the usual dose is 250 mg two or three times daily.