The general pharmacological actions of recombinant human growth hormone (rHGH) were investigated. It had hypothermic action but neither sedative nor analgesic action. No pharmacological effects were observed in isolated guinea pig ileum and tracheal muscle and rat fundus and uterus. Slight hypotensive action with no effect on respiration was revealed at a dose of 20 IU/kg i.v. of rHGH in rabbits. The rHGH exhibited a weak inhibitory action of glucose tolerance in normal rats, significantly lowered the blood glucose contents in adrenalectomized rats 20 min after i.v. administration (80IU/kg), and produced a significant inhibitory effect on in vitro glycerol release in epinephrine-stimulated epididymal fat pad segments of rats.