Cysteine is a non-essential amino acid important for making protein, and for other
metabolic functions. It's found in beta-keratin. This is the main protein in nails,
skin, and hair. Cysteine is important for making collagen. It affects skin elasticity
and texture. Cysteine has antioxidant properties.
There may be benefits that have not yet been proven through research.
A form of cysteine called L-cysteine may help treat arthritis and hardening of the
arteries. It may help treat certain lung diseases. These include bronchitis, emphysema,
Cysteine may play a role in the normal growth rate of hair. Cysteine may also help
reduce the effects of aging on the skin. It may help healing after surgery or burns
and protect the skin from radiation injury.
Cysteine may help burn fat and increase muscle mass.
Amino acids (AAs) are available as single AAs or in AA combinations. They also come
as part of multi-vitamins, proteins, and food supplements. The forms include tablets,
fluids, and powders.
By eating enough protein in your diet, you get all of the amino acids you need.
There are no conditions that increase how much cysteine you need.
Side effects, toxicity, and interactions
Using a single amino acid supplement may lead to negative nitrogen balance. This can
lessen how well your metabolism works. It can make your kidneys work harder. In children,
single amino acid supplements may cause growth problems.
Don't take high doses of single amino acids for long periods of time.
Don't use cysteine supplements if you are pregnant or breastfeeding.
Don't use cysteine if you have either of these:
Diabetes. Cysteine may interfere with how insulin works.
Cystinuria. This is a rare genetic condition. It causes cystine build up. Cystine is related
to cysteine. This buildup may lead to kidney stones that can block the urinary tract.