5-Hydroxytryptophan (5-HTP) is a precursor to the neurotransmitter serotonin.
The reaction that causes 5-HTP to become serotonin requires the action of the enzyme aromatic-L-amino-acid decarboxylase (AADC). Vitamin B6 is also required as a cofactor. The same enzyme catalyzes a number of other reactions, including:
- L-DOPA to dopamine
- L-phenylalanine to phenethylamine
- L-tyrosine to tyramine
- L-histidine to histamine
- L-tryptophan to tryptamine
5-HTP has been shown to increase serotonin levels in the central nervous system.
Reports about serotonin levels in ME/CFS patients are mixed. One study hypothesized, based off of their findings on tryptophan, that ME/CFS patients fell into two groups: a group with high brain serotonin, and a group with normal serotonin. Multiple studies have found high, low, or normal serotonin, due either to different diagnostic criteria or ME/CFS subgroups.
Learn more[edit | edit source]
See also[edit | edit source]
References[edit | edit source]
- "AADC". Human Metabolome database. Retrieved 1 May 2018.
- Turner, Erick H; Loftis, Jennifer M; Blackwell, Aaron D (2006). "Serotonin a la carte: Supplementation with the serotonin precursor5-hydroxytryptophan". Pharmacology & Therapeutics. 109 (3).
- Badawy AAB, AAB; Morgan, CJ; Llewelyn, MB; Albuquerque, SRJ; Farmer, A (2005). "Heterogeneity of serum tryptophan concentration and availability to the brain in patients with the chronic fatigue syndrome". Journal of Psychopharmacology. 19 (4): 385–391.