That's a pretty common myth spread by articles like this one[0]. Wikipedia's article on Cysteine debunks it[1]: The majority of L-cysteine is obtained industri

That's a pretty common myth spread by articles like this one[0]. Wikipedia's article on Cysteine debunks it[1]: The majority of L-cysteine is obtained industrially by hydrolysis of animal materials, such as poultry feathers or hog hair. Despite widespread belief otherwise, there is little evidence that human hair is used as a source material and its use is explicitly banned in the European Union. Makes sense too, since ~50 billion chickens are slaughtered per year, the amount of poultry feathers available for processing probably dwarfs the amount of human available. [0] http://www.naturalnews.com/032718_L-cysteine_commercial_bread.html http://www.naturalnews.com/032718_L-cysteine_commercial_brea... [1] https://en.wikipedia.org/wiki/Cysteine https://en.wikipedia.org/wiki/Cysteine