As it is known to most of the people that amino acids are the building blocks of proteins. And a large number of tissue, muscles and cells are made up of amino acids. Amino acids can be procured from animal source as well as non-animal source.L-cysteine is one of those sulfur-containing amino acids which helps the body to function properly.It may be used as a supplement for cell culture media in many industries. Beside this, it has many health benefits also.L-cysteine is very beneficial for healthy skin, hair, and nails. It aids in the formation of collagen. And its deficiency may lead to disturbance in the whole body function. Vegetarians are likely to suffer from L-cysteine deficiency because it is normally found in red meat, seafood etc. And this is a non-animal source of l-cysteine which is very beneficial for vegetarians also.