Together with UGT2B4, UGT2B7 is capable of glucosidation of hyodesoxycholic acid in the liver, but, unlike the 2B4 isoform, 2B7 is also able to glucuronidate various steroid hormones (androsterone, epitestosterone) and fatty acids. It is also able to conjugate major classes of drugs such as analgesics (morphine), carboxylic nonsteroidal anti-inflammatory drugs (ketoprofen), and anticarcinogens (all-trans retinoic acid). UGT2B7 is the major enzyme isoform responsible for the metabolism of morphine, codeine, norcodeine and other opiates to their corresponding 3- and 6- glucuronides. For example, morphine metabolism produces morphine-3-glucuronide (M3G) which has no analgesic effect and morphine-6-glucuronide (M6G), which has analgesic effects more potent than morphine. As a consequence, altered UGT2B7 activity can significantly affect both the effectiveness and side-effects of morphine, as well as some related opiate drugs.
