From MEpedia, a crowd-sourced encyclopedia of ME and CFS science and history

5-Hydroxytryptophan (5-HTP) is a precursor to the neurotransmitter serotonin.[1]

Theory[edit | edit source]

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.[1] The same enzyme catalyzes a number of other reactions,[1] including:

5-HTP has been shown to increase serotonin levels in the central nervous system.[2]

Evidence[edit | edit source]

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.[3] Multiple studies have found high, low, or normal serotonin, due either to different diagnostic criteria or ME/CFS subgroups.[3]

Risks and safety[edit | edit source]

Because 5-HTP increases brain serotonin, users are at risk for serotonin syndrome if they also take other medications which increase brain serotonin,[4]. Medications which come under this category and which are commonly taken be ME/CFS patients include:

Other medications, including other supplements, may also increase brain serotonin - make sure you tell your pharmacist and your doctor if you are taking 5-HTP.

Costs and availability[edit | edit source]

Learn more[edit | edit source]

See also[edit | edit source]

References[edit | edit source]

  1. 1.0 1.1 1.2 "AADC". Human Metabolome database. Retrieved May 1, 2018.
  2. Turner, Erick H; Loftis, Jennifer M; Blackwell, Aaron D (2006). "Serotonin a la carte: Supplementation with the serotonin precursor5-hydroxytryptophan". Pharmacology & Therapeutics. 109 (3).
  3. 3.0 3.1 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.
  4. "5-HTP Uses, Side effects, Interactions, Doses, and Warnings". WebMD. Retrieved May 29, 2018.