Taurine, which is a derivative of the sulfur containing amino acid cysteine, is found throughout the body, especially in muscle and nerve tissue. (ironmagazine.com)
When you consume the semi-essential amino acid cysteine, the body breaks it down into hydrogen sulfide. (drstevenlin.com)
Because of this, Zetpil Complete Protein Amino Acid Formula Suppositories contain essential amino acids leucine, isoleucine, valine, lysine, threonine, and tryptophan, and conditional amino acids cysteine and tyrosine. (drvitaminsolutions.com)