Our body uses cysteine which is an amino acid with the chemical formula HO2CCH(NH2)CH2SH, as most of the amino acids are used i.e. building blocks of proteins. It is a non-essential amino acid. Foods that have high protein content are usually the one’s that contain cysteine. Some major sources are dairy products, poultry products and meats. Some of the plant sources are granola, onions, red peppers, lentils etc. N-acetyl-L-cysteine (NAC) is the form when it ingested as a supplement. The amino acid in context is converted from the above chemical and then converted into glutathione which is a potent antioxidant.

The free radicals present in our bodies are fought by these antioxidants. Radicals are injurious compounds that harm the DNA and the cell membrane. Many problems have been associated with radicals, such as cancer, breaking down the mucus in body etc. Cysteine, mainly the L-enantiomer, is a precursor in personal-care, pharmaceutical and food industries.


  • Cysteine also comes into play in the development of flavors. For instance, in the Maillard reaction, it reacts with sugars to give us meaty flavors. The art of baking uses it as a processing aid.
  • Asian countries also use it for personal care applications.
  • Biomolecular structures and its dynamics are explored by the use of this chemical.
  • Cigarettes also contain cysteine.
  • It acts as an antidote for hangover and liver damage. It is also used to treat schizophrenia.
  • Patients of type 2 diabetes are also helped by this amino acid as it controls the blood sugar level. Emphysema, cystic fibrosis and asthma have shown great response to this chemical.

Source in Diet

Cysteine is created from methionine (essential amino acid) by our body. Some of the foods that have the amino acid are enlisted below

  • Sausage meat
  • Granola
  • Lunch meats
  • Ricotta
  • Oat flakes
  • Chicken
  • Pork
  • Duck
  • Cottage cheese
  • Turkey
  • Yogurt
  • Wheat germ

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In India, agriculture depends only on rainfall.