(April 14, 2002) eat-halal.com would like to warn Muslim consumers about L-cysteine. L-cysteine is an ingredient which is used in bakery products as a dough conditioner. It is often used in pizza crusts, pita breads and in bagels. It is made from human hair, chicken/duck feathers and synthetic materials. L-cysteine from human hair is Haram and must always be avoided. Synthetic and chicken/duck feather L-cysteine is Halal and may be consumed. eat-halal.com has also learned that some Canadian Pizza Hut items contain L-cysteine from duck feathers. Domino's pizza dough also contain L-cysteine, but the source is unknown. Pizza Hut may be contacted at (800) 363-1601 and Domino's may be reached at (888) DOMINOS.