Growth hormone responses to melatonin in man.

Oral administration of 1 gram of melatonin caused rapid and significant elevations of serum human growth hormone in eight out of nine normal male subjects. The mean (+/- standard error of the mean) of the peak response by growth hormone was 22.9 +/- 4.6 microunits per milliliter. The increased secretion of growth hormone may be due to interaction of melatonin with hypothalamic serotoninergic receptors.