The recent EEC Directive banning the use of anabolic agents as growth promoters in animal production in countries of the EEC and, by implication, prohibiting imports of fresh and processed meats from countries not applying a similar ban, has raised undue concern by research scientists involved in studies of the biochemistry and physiology of growth promoters. In addition to the well established growth response and improved carcass composition obtained from using anabolic agents (both naturally occurring hormones and zenobiotic compounds), there are exciting developments involving new pharmacological agents, new immunological techniques and the possibility of direct manipulation of the genome.