indication

It has been claimed that L-cysteine has anti-inflammatory properties, that it can protect against various toxins, and that it might be helpful in osteoarthritis and rheumatoid arthritis. More research will have to be done before L-cysteine can be indicated for any of these conditions. Research to date has mostly been in animal models.

pharmacology

L-Cystine is a covalently linked dimeric nonessential amino acid formed by the oxidation of cysteine. Two molecules of cysteine are joined together by a disulfide bridge to form cystine. Cystine is a chemical substance which naturally occurs as a deposit in the urine, and can form a calculus (hard mineral formation) when deposited in the kidney. The compound produced when two cysteine molecules linked by a disulfide (S-S) bond. Cystine is required for proper vitamin B6 utilization and is also helpful in the healing of burns and wounds, breaking down mucus deposits in illnesses such as bronchitis as well as cystic fibrosis. Cysteine also assists in the supply of insulin to the pancreas, which is needed for the assimilation of sugars and starches. It increases the level of glutathione in the lungs, liver, kidneys and bone marrow, and this may have an anti-aging effect on the body by reducing age-spots etc.

mechanism of action

Certain conditions, e.g. an acetaminophen overdose, deplete hepatic glutathione and subject the tissues to oxidative stress resulting in loss of cellular integrity. L-Cystine serves as a major precursor for synthesis of glutathione.

toxicity

With typical doses of 1 to 1.5 grams daily, the most commonly reported side effects have been gastrointestinal, such as nausea. There are rare reports of cystine renal stone formation, Single injections of L-cysteine (0.6-1.5 g/kg) into 4-day-old pups resulted in massive damage to cortical neurons, permanent retinal dystrophy, atrophy of the brain and hyperactivity.