There is massive evidence that low serotonin levels are a common consequence of modern living. The lifestyles and dietary practices of many people living in this stress-filled era result in lowered levels of serotonin within the brain. As a result, many people are overweight, crave sugar and other carbohydrates, experience bouts of depression, get frequent headaches, and have vague muscle aches and pain. All of these maladies are correctable by raising brain serotonin levels.

Conditions associated with low serotonin levels helped by 5-HTP include depression, obesity, carbohydrate craving, bulimia, insomnia, narcolepsy, sleep apnea, migraine headaches, tension headaches, chronic daily headaches, premenstrual syndrome and fibromyalgia.

5-hydroxytryptophan (5-HTP) is a precursor to serotonin. In the body, the essential amino acid tryptophan (when acted upon by the enzyme tryptophan hydroxylase) converts to 5-HTP. The compound is subsequently decarboxylated to serotonin, thereby elevating extracellular serum serotonin levels.

Mood and Comfort: Serotonin regulates many normal brain activities, increases norepinephrine and dopamine, and is important in regulating mood and behavior. Adequate levels of serotonin are associated with normal calmness and relaxation [1-4]. Several studies have demonstrated that 5-HTP supports a healthy frame of mind, good energy levels, ease of movement, and restful sleep [1,5,6].

Appetite: Used in a high dose (i.e., 300 mg/three times a day), 5-HTP decreased food consumption and reduced weight. This result may relate to the effect of 5-HTP in supporting normal hypothalamic regulation, which includes appetite homeostasis [7]. However, nausea at this relatively high dose was a common complaint [8,9]. In other research, sublingual 5-HTP administered five times per day for eight weeks in adult overweight women significantly supported feelings of post-meal hunger satisfaction [10].

Hormones and Sleep: 5-HTP is thought to effect the HPA (hypothalamic-pituitary-adrenal) axis, as it has the ability to raise plasma cortisol levels, to cause transient increase in growth hormone (at 150 mg dose), and in men only, to support healthy levels of thyroid stimulating hormone [11,12]. Serotonin is also converted to melatonin; thus, supplementation has similar effects. Support of sleep quality is likely related to 5-HTP’s ability to increase the length of rapid eye movement (REM) [2,13].

CAUTIONS: Do not use with other dietary supplements containing L-tryptophan, 5-HTP, St. John’s wort, SAMe, or Hawaiian baby woodrose. Do not take if you are, or suspect you are, pregnant or if you are lactating, or under 18 years of age.

References

1. Juhl JH. Fibromyalgia and the serotonin pathway. Altern Med Rev. 1998 Oct;3(5):367-75. [PMID: 9802912]
2. Birdsall TC. 5-Hydroxytryptophan: a clinically-effective serotonin precursor. Altern Med Rev. 1998 Aug;3(4):271-80. [PMID: 9727088]
3. Agren H, Reibring L, Hartvig P, et al. Low brain uptake of L-[11C]5- hydroxytryptophan in major depression: a positron emission tomography study on patients and healthy volunteers. Acta Psychiatr Scand. 1991;83(6):449-55. [PMID: 1882697]
4. Zmilacher K, Battegay R, Gastpar M. L-5-hydroxytryptophan alone and in combination with a peripheral decarboxylase inhibitor in the treatment of depression. Neuropsychobiology. 1988;20(1):28-35. [PMID: 3265988]
5. Caruso I, Sarzi Puttini P, Cazzola M, et al. Double-blind study of 5-hydroxytryptophan versus placebo in the treatment of primary fi bromyalgia syndrome. J Int Med Res. 1990 May-Jun;18(3):201-09. [PMID: 2193835]
6. Puttini S, Caruso I. Primary fi bromyalgia syndrome and 5-hydroxy-L-tryptophan: a 90-day open study. J Int Med Res. 1992 Apr;20(2):182-89. [PMID: 1521674]
7. Schott DA, Nicolai J, de Vries JE, et al. Disorder in the serotonergic system due to tryptophan hydroxylation impairment: a cause of hypothalamic syndrome? Horm Res Paediatr. 2010;73(1):68-73. [PMID: 20190542]
8. Cangiano C, Ceci F, Cascino A, et al. Eating behavior and adherence to dietary prescriptions in obese adult subjects treated with 5-hydroxytryptophan. Am J Clin Nutr. 1992 Nov;56:863-67. [PMID: 1384305]
9. Cangiano C, Laviano A, Del Ben M, et al. Effects of oral 5-hydroxy-tryptophan on energy intake and macronutrient selection in non-insulin dependent diabetic patients. Int J Obes Relat Metab Disord. 1998 Jul;22(7):648-54. [PMID: 9705024]
10. Rondanelli M, Klersy C, Iadarola P, et al. Satiety and amino-acid profi le in overweight women after a new treatment using a natural plant extract sublingual spray formulation. Int J Obes (Lond). 2009 Oct;33(10):1174-82. [PMID: 19752879
11. Lee MA, Nash JF, Barnes M, et al. Inhibitory effect of ritanserin on the 5-hydroxytryptophan-mediated cortisol, ACTH and prolactin secretion in humans. Psychopharmacology (Berl). 1991;103(2):258-64. [PMID: 1851310]
12. Mashchak CA, Kletzky OA, Spencer C, et al. Transient effect of L-5- hydroxytryptophan on pituitary function in men and women. J Clin Endocrinol Metab. 1983 Jan;56(1):170-76. [PMID:6600170]
13. Wyatt RJ, Zarcone V, Engelman K, et al. Effects of 5-hydroxytryptophan on the sleep of normal human subjects. Electroencephalogr Clin Neurophysiol. 1971 Jun;30(6):505-09. [PMID: 4105646]