Human growth hormone (hGH) stimulates the growth rate in children with GH deficiency, but also in children secreting GH, when given in higher doses. Concomitantly, there is an anabolic effect on the protein metabolism and an anticatabolic effect by increasing the content of free fatty acids. Growth hormone may be helpful in management of patients with subfertility or hypogalacty. The hormone increases the amount of muscles and decreases the fat of skin in adults with GHD. Biosynthetic products should be used since pituitary hGH could transmit diseases from the organ donors. No oncogenic properties have been confirmed. Only hGH is effective in man, since there is a marked species specificity.