Q Does 5-HTP release growth hormone like tryptophan does?

A A significant effect on growth hormone release in humans after oral ingestion of 2 grams of L-tryptophan has been demonstrated.1 I would expect a similar rise with 50-100 mg of 5-HTP. Furthermore, there is evidence that melatonin may enhance growth hormone secretion,2-3 and 5-HTP is a precursor of serotonin and melatonin. So although the data are not conclusive with regard to tryptophan and growth hormone, I believe that tryptophan and 5-HTP probably significantly enhance the release of growth hormone in humans.


  1. Hyyppa MT, Jolma T, Liira J, Langvik VA, Kytomaki O. L-tryptophan treatment and the episodic secretion of pituitary hormones and cortisol. Psychoneuroendocrinology 1979;4:29-35.
  2. Smythe, G.A., and Lazarus, L. Growth hormone regulation by melatonin and serotonin. Nature 1973;244:230-231.
  3. Valcavi R, Zini M, Maestroni G, and Conti A. Melatonin stimulates growth hormone secretion through pathways other than the growth-hormone releasing hormone. Clinical Endocrinology 1993;39:193-199.