As we know L-cysteine could be an amino acid that contributes to battling fatigue and healthy skin, hair and nails. The problem? To produce this amino acid cheaply human hair and duck feathers are dissolved (probably with something along the lines of hydrochloric acid), L-cysteine is isolated and then reconstituted into tablet/powder forms. The hair and feathers are mostly obtained from china. This poses not only nutritional concerns but ethical implications too from the chemicals used to process the ingredients to animal cruelty issues from vegetarians like myself. It also raises the question of what other amino acids are derived from shady sources and nutritional supplements as a whole?

If anyone knows of labs that produce high quality products and makes it a habit to disclose how they obtain their ingredients I would really love to know about it.

Here is an article that sums up a lot of issues that are deemed rational by the FDA and slip passed the EPA.