The regulation of growth hormone (GH) secretion in humans is a complex entity involving primary regulators and secondary modifiers that influence both the amount and pattern of GH release. The primary regulators are the hypothalamic hormones: somatostatin (SRIH) and growth hormone releasing hormone (GHRH). Some of the known modulators of GH release include gonadal steroid concentrations, body composition (weight), ingestion of food, age, and physical exercise. The importance of GH in the adult is now being recognized as influencing muscle mass, muscle strength, and nutrient utilization. With the discovery of GHRH and growth hormone releasing peptides (GHRPs), several issues have arisen regarding the feasibility and advisability of increasing GH secretion in adults. The primary issues are (i) Is the pattern of exposure to GH im­portant in maximizing its effects? (ii) Is continuous exposure to GH harmful? and (iii) Is it possible to effect pulsatile growth hormone secre­tion with the use of GHRH or a GHRP?