17?, 19-nortestosterone, commonly known as nandrolone, is an anabolic androgen given by mouth and by injection. It is a natural hormone in some animal species and is illegally used in animal husbandry as an anabolic. Following intramuscular injection of 19-nortestosterone laurate, the main metabolite identified in urine and bile is 17?, 19-nortestosterone.(10) 17?, 19-nortestosterone is reported to be naturally occurring in pregnant cattle, but has not been identified in untreated male cattle. (11)