What is 5-HTP?
is a naturally occurring amino acid, found as an intermediate metabolite in the biosynthesis of serotonin (5-hydroxytryptamine) from the essential amino acid L-tryptophan1
. It is produced commercially from the seeds of Griffonia simplicifolia
, a tropical shrub found in West Africa. Both L-tryptophan and 5-HTP help raise serotonin levels in the brain, which may have a positive effect on sleep, mood, anxiety, aggression, appetite control, temperature, sexual behavior and pain sensation5
. 5-HTP is not commonly found in food, but the amino acid L-tryptophan can be found in such foods as turkey, chicken, milk, potato, turnips and collard greens.
Serotonin was first isolated in 1937 from material derived from gastric and intestinal tissues. It had the ability to cause smooth muscle contraction and was named enteramine2. At the same time, another group of scientists was looking for the agent causing hypertension and isolated a substance from serum that caused blood vessels to constrict, and named it serotonin3. After a close examination of the two substances, they were found to be identical4.
Serotonin is widely found in nature. In plants it can be found in edible fruits, vegetables and nuts. In animals, it’s present in both invertebrates and vertebrates; localized in GI tissue lining, serotogenic neurons of the brain, the pineal gland (located near the center of the brain and associated with making the antioxidant/sleep hormone melatonin from serotonin) and in blood platelets.
What does 5-HTP do?
Serotonin is involved in a variety of physiological processes, including smooth muscle contraction, blood pressure regulation, and both peripheral and central nervous system neurotransmission. In the central nervous system, it acts as a neurotransmitter5. It is synthesized from tryptophan in the brain, spinal cord, GI tract, bronchi, thyroid, pancreas and thymus. The serotonin circulating in our blood vessels does not normally enter the brain, as it cannot cross an intact blood-brain barrier, so must be made in the brain from 5-HTP or tryptophan.
In 1989, ingestion of some batches of L-tryptophan caused an outbreak of eosinophilia myalgia syndrome (EMS), a potentially fatal disorder that affects the skin, blood, muscles and organs (FDA 1998). This led to an FDA warning and a voluntary recall on over-the-counter sales of tryptophan. The FDA allows tryptophan to be sold if the manufacturer has a reasonable assurance of safety, and admits that no single cause has been determined for the EMS outbreak.6 New research points to elevated histamine levels as the key trigger for EMS.7
Although the manufacturing of 5-HTP from beans does not use the same processes as bacterial fermentation to produce L-tryptophan (a process utilizing bacteria, a growth medium and special filters) there were some theoretical concerns about 5-HTP. No official cause for the EMS epidemic has ever been determined, though several possibilities have been identified, including a new genetically engineered growth bacteria, a failed filtering system and a previously unknown contaminant. The so-called contaminant is referred to as “Peak X”8, which was later identified as tryptophan-4,5-dione, a reputed neurotoxin9. However, a link between 5-HTP and Peak X or EMS has never been demonstrated, and there are no similarities in the production of tryptophan and 5-HTP.
A 2004 toxicology review stated that “Extensive analyses of several sources of 5-HTP have shown no toxic contaminants similar to those associated with L-Trp (tryptophan), nor the presence of any other significant impurities. A minor chromatographic peak (peak X) reported in some 5-HTP samples lacks credibility due to chromatographic artifacts and infinitesimal concentrations, and has raised undue speculations concerning its chemistry and toxicity.” 10 This means that a major toxicology journal has published a review study stating that there is no reputable science indicating that 5-HTP may be unsafe due to a toxic contaminant.
NOW Foods, to ensure the safety of its customers, still requires that all of our 5-HTP be analyzed for the absence of “Peak X” or other unusual test results. Only the purest, highest quality material is approved. Our state-of-the-art in-house lab uses high performance liquid chromatography (HPLC) to analyze the identity and potency of our products. This is how we ensure that the quality and safety of our products meet our safety standards. And since any 5-HTP taken orally is well absorbed and crosses the blood-brain barrier11, this provides a natural way to maintain a healthy level of serotonin in the body.
1 Bell, E.A., et al., Nature, 210, 529 (1966)
2 Ersparmer, V., Arch. F. Pathol. Pharm., 196, 366 (1940)
3 Rapport, M.M., et al., J. Biol. Chem., 176, 1243 (1948)
4 Ersparmer, V., et al., Nature, 169, 800 (1952)
5 Kema, I.P., et al., J. Chrom. B, 747, 33-48 (2000)
6 U. S. Food and Drug Administration, Center for Food Safety and Applied Nutrition, Office of Nutritional Products, Labeling, and Dietary Supplements. February 2001. Information Paper on L-tryptophan and 5-hydroxy-L-tryptophan
7 Inflamm Res. 2005 Nov;54(11):435-50
8 Michelson, D., et al., J. Rheumatol., 21, 2261-2265 (1994)
9 Klarskov, K.L., et al., Adv. Exp Med Bio, 467, 461-468 (1999)
10 Das, YT et al. Toxicol Lett. 2004 Apr 15;150(1):111-22
11 Magnussen, I.E., et al., Acta Pharma. Toxicol., 46, 257 (1980)