Growth hormone secretagogues (GHSs) are synthetic molecules that stimulate and amplify pulsatile pituitary growth hormone release, via a separate pathway distinct from GH releasing hormone/somatostatin. The activity of GHSs is not fully specific for GH secretion; some GHSs also have slight releasing activity on other pituitary hormones and mediate GH independent biological activities. The first GHSs were discovered in 1977. Since then, an intensive research to synthesize a potent oral GHSs has been undertaken. Although the potential applications of GHSs are numerous, long term trials are needed to evaluate the clinical efficacy and safety of these substances. In the present article we review the historic background of GHSs, their potential clinical uses, the types and the main GHSs that have been synthesized hitherto.