200 to 300 mg per day, with dose scheduling ranging two- to four-times per day. Their
recommended dosing frequency was three times per day.- RESEARCH: Long-term outcomes -- benefits and liabilities from continuing treatment with 5-
HTP or tryptophan and comparative assessment with other drugs -- require further
investigation, as do the systematic tracking, reporting and quantification of adverse effects.
The studies are all old, small, and short-term. Despite its popularity, 5-HTP is truly an
orphan supplement. Research needs to consider long-term as well as short-term effects and
needs to catch up with consumer use. Prompt government and academic attention are
required.
1
Lake, J.A. and Spiegel, D., Complementary and Alternative Treatments in Mental Health Care, American
Psychiatric Publishing, Inc., Washington (2007), at 135.
(^2) Walinder, J., Skott, A., Carlsson, A., Nagy, A. &, Bjorn-Erik, R., “Potentiation of the Antidepressant Action of
Clomipramine by Tryptophan,” Arch. Gen. Psychiatry 33:1384 – 9 (1976).
(^3) Iovieno, N., Dalton E. D., Fava, M. & Mischoulon, D., “Second-tier Natural Antidepressants: Review and Critique,”
Journal of Affective Disorders 130(3):343-57 (2011), at 350.
(^4) Das, Y.T., Bagchi, M., Bagchi, D. & Preuss, H.G., “Safety of 5-HTP,” Toxicology Letters 150(1):111-122 (2004).
(^5) Turner, E.H., Loftus, J.M. & Blackwell, A.D., “Serotonin à la Carte: Supplementation with the Serotonin Precursor
5 - HTP,” Pharmacology and Therapeutics 109(3):325-338 (2006).
(^6) Muskin, P.R., Gerbarg, P.L., and Brown, R.P., Complementary and Integrative Therapies for Psychiatric Disorders,
Psychiatric Clinics of North America, copyright Elsevier, Inc., Philadelphia ( 2013 ) (“Brown et al. II”) at 31.
(^7) Lake, J.A. and Spiegel, D., op. cit. at 136.
(^8) Turner et al, op. cit. at 351.
(^9) Das, et al., op. cit. ( 2004 )
(^10) Das, Y.T., Bagchi, M., Bagchi, D. & Preuss, H.G., “Safety of 5 - hydroxy-L-tryptophan,” Toxicol Lett 150(1):111- 22
(2004).