I was speaking to some chemists recently that claimed some U.S. nutritional supplements have human hair as an ingredient. They went on to mention that the hair is often sourced from China and lately has tested for higher levels of heavy metals.
I can not verify the above claim from an internet search. But does anyone know why the protein in hair might be more beneficial as a supplement than other forms of protein ?
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.
There is a Dutch television programme that does research on ingredients of common food products, to check where the ingredients come from. Sometimes based of speculation, but they tend to back it up with scientific research.
One of the suppliers actually confirms that human hair is being used in production, and being sold to bakeries around the world. While European bakeries claim to only use the l-cystein from animal sources, this video tends to show otherwise.
[0] https://en.wikipedia.org/wiki/2008_Chinese_milk_scandal