Growth hormone from human pituitary glands has been available for 30 years. Because of the scarce supply and the danger of transmitting Creutzfeldt-Jakob disease, use of the hormone was discontinued in 1984. Fortunately, synthetic growth hormone produced with recombinant DNA technology became available in 1985 and eliminated the risk of Creutzfeldt-Jakob disease. Growth hormone is approved for use in the treatment of pituitary deficiency syndromes and, when properly administered at an early stage, is capable of inducing normal skeletal and muscular development. It also has been successfully used to augment growth in patients with Turner's syndrome or constitutional growth delay not associated with obvious growth hormone defects. Side effects are generally not serious, but antibodies to growth hormone develop in about 30 percent of patients.