5-Hydroxytryptophan

5-Hydroxytryptophan (5-HTP), also known as oxitriptan, is a naturally occurring amino acid and chemical precursor as well as a metabolic intermediate in the biosynthesis of the neurotransmitter serotonin. 5-HTP is sold over the counter in the United States, Canada, the Netherlands, and the United Kingdom as a dietary supplement for use as an antidepressant, appetite suppressant, and sleep aid. It is also marketed in many European countries for the indication of major depression under the trade names Cincofarm, Levothym, Levotonine, Oxyfan, Telesol, Tript-OH, and Triptum. A 2002 review concluded that although the data evaluated suggests that 5-HTP is more effective than placebo in the treatment of depression, the evidence was insufficient to be conclusive due to a lack of clinical data meeting the rigorous standards of today. More and larger studies using current methodologies are needed to determine if 5-HTP is truly effective in treating depression. In small controlled trials 5-HTP has also been reported to augment the antidepressant efficacy of the antidepressant clomipramine. 5-HTP is sometimes taken by people coming down from MDMA to relieve post-MDMA dysphoria. As 5-HTP is a necessary precursor for the brain to produce more serotonin, and MDMA use depletes a person's natural serotonin levels, it is believed that taking 5-HTP after consuming MDMA will speed up serotonin production. DanceSafe claims that the anecdotal evidence is widespread and that the theory is physiologically reasonable. Backing up this approach is research conducted by Wang, et al. in 2007, which observed that MDMA-induced depletions of 5-HT (serotonin) were restored in rats after administration of 5-HTP, and suggested that this approach might be clinically useful in abstinent MDMA users. At high doses, or in combination with carbidopa, it has been used off-label to treat obesity (by promoting weight loss). In clinical trials of various design, 5-HTP has also been reported to treat fibromyalgia, myoclonus, migraine, and cerebellar ataxia. However, these clinical findings, as for all therapeutic findings with 5-HTP, are preliminary and need confirmation in larger trials. The short half-life (<2h) of 5-HTP may inherently limit the therapeutic potential of 5-HTP, as the systemic 5-HTP exposure levels will fluctuate substantially, even with relatively frequent dosing. Such exposure fluctuations are usually associated with increased adverse event burden, resulting from Cmax drug spikes, and decreased clinical efficacy resulting from sub-therapeutic exposure for large parts of the day. It has been proposed that 5-HTP dosage forms achieving prolonged delivery would be more effective, as is generally the situation with short-acting active pharmaceutical ingredients. Potential side effects of 5-HTP include heartburn, stomach pain, nausea, vomiting, diarrhea, drowsiness, sexual problems, vivid dreams or nightmares, and muscle problems. Because 5-HTP has not been thoroughly studied in a clinical setting, possible side effects and interactions with other drugs are not well known. According to the US National Institute of Health TOXNET, 5-HTP has not been associated with serotonin syndrome or any serious adverse events in humans. Across multiple studies, 5-HTP has also been reported to not cause any noticeable hematological or cardiovascular changes. 5-HTP has also been associated with eosinophilia, but later studies have not found any causal connection.