Cysteine is an amino acid that is used in hair treatment products due to its ability to strengthen and straighten hair. It can be used in hair treatment compositions in an amount of 3 to 10% by weight, calculated as cysteine, of cysteine or its salt.
There are positive effects of using cysteine in hair treatment products, such as strengthening and straightening hair.
However, there are also negative effects such as flaking and irritation to the skin.
Other ingredients found in hair treatment products include glyoxylic acid, cetrimonium chloride, and polyquaternium 37.
