Norhyodeoxycholic acid (NHDCA) is a synthetic bile acid and a derivative of hyodeoxycholic acid (HDCA; Item No. 20294).{53355,53356} NHDCA is an intermediate in the synthesis of 3B-sulfooxy-7B-hydroxy-24-nor-5-cholen-23-oic acid, which has been used as an internal standard for the quantification of D5-bile acid conjugates that have been identified in patients with Niemann-Pick disease type C1.{53357}