5-HTP
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5-HTP
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Clinical data for each condition:
Aggression, Alcoholism or alcohol withdrawal, Amphetamine intake, Appetite suppressant, Depression, Excessive Coughing, Fibromyalgia, Insomnia, Lesch-Nyhan syndrome, Migraine prophylaxis, Myoclonus, Obesity, Panic, Stress, Weight loss programs.
Functions
Facilitated:
Precursor of
Serotonin synthesis
General Discussion:
5 Hydroxy tryptophan (5-HTP) is one of the transitional chemicals formed when tryptophan is converted to serotonin. Serotonin has a variety of physiological actions, but primarily it affects the brain. In the ventro-medial hypothalmus it regulates appetite, in the midline raphe nuclei of the brain, serotonin induces sleep and in the cerebrospinal fluid it has an anti-depressive effect. 5-HTP is also a precursor of melatonin. It crosses the blood brain barrier quite easily and influences the serotonergic nervous system.
Researches into mental illness became interested in tryptophan in 1971, when Wurtman and colleagues discovered that the brain neurotransmitter serotonin was dependent upon tryptophan intake. The main enzyme involved in the metabolism of tryptophan is hydroxylase. This enzyme starts the conversion of aromatic amino acids to neurotransmitters. It requires pyridoxine and magnesium to perform this function.
5-HTP - Addiction and
Pain
The basis for the effect
of 5-HTP on pain lies in the area of the brain called the nucleus raphus
magnus, a primary pain inhibiting area. The nucleus raphus magnus is the
brain’s major serotonergic structure, thus it depends on serotonin and
its precursor tryptophan for optimal function.
Serotonin levels are increased by the intake of addictive substances. It has been found that serotonin levels plummet during withdrawal. Pain sensitivity increases when brain serotonin levels are low. Pain sensitivity is markedly impaired during alcohol intoxication, which temporarily increases serotonin levels in the brain.
An open 90 day study of 50 patients affected by primary fibromyalgia syndrome (PFS) showed that all clinical parameters studied were significantly improved by the treatment of 5-HTP.
5-HTP and Migraines
Migraines headaches are closely associated with serotonergic activity. A number of studies found that 5-HTP may be able to prevent migraines and tension headaches, the authors of one study suggested it as a treatment of choice.
5-HTP and Sleep
5-HTP can induce sleep
when taken on an empty stomach about one hour before going to bed. Both
5-HTP and serotonin are precursors to melatonin. Melatonin production is
indirectly suppressed by light going into the eye, and its levels are directly
augmented by the availability of the precursor 5-HTP.
5-HTP and Depression and Anxiety
Depression has been subcategorised into unipolar or bipolar, high histamines or low histamines, serotonergic or catecholamine excess or deficiency. The unipolar, high histamine, serotonergic excess depression (catecholamine deficiency) is a flat effect or low energy depression, while bipolar, low histamine, catecholamine excess depression is an agitated form. 5-HTP is useful in the agitated or bipolar form, as it is the principal monoamine that functions as a neurotransmitter in the brain.
Depression and irritability related to pre menstrual syndrome in women taking the contraceptive pill has been attributed to the depletion of vitamin B6, which results in a reduction in the amount of tryptophan available for serotonin synthesis in the brain.
5-HTP helps reduce anxiety as it increases serotonin’s availability. It appears to affect consciousness by helping the brain better maintain stimulus barriers which in turn can improve your ability to "parallel-process" multiple spheres of mental activity without becoming overwhelmed, unable to choose and anxious.
Hans Selye observed that stress resulted in an increased level of the hormone cortisol. Cortisol which is responsible for the ‘fight, flight or fright" response, in high levels reduces levels of brain serotonin. Long term exposure to cortisol may damage certain serotonin producing nerves in the brains of animals.
A double blind comparison of 5-HTP and an SSRI (Selective serotonin reuptake inhibitor) antidepressant found that both produced near equal reduction in depression, and 5-HTP producing slightly greater improvement in mean percentage change from baseline. Overall, 5-HTP, appeared to be better tolerated that the SRRI.
5-HTP and Aggressive behaviour
Some evidence suggests that serotonin and tryptophan may inhibit aggressive behaviour in experimental animals and humans. Epidemiologic studies suggest that in areas where corn is a major dietary staple (resulting in a deficient dietary intake of tryptophan), rates of homicide and other forms of criminality are increased.
5-HTP as an Appetite Suppressant
A relative deficiency of serotonin is also believed to be associated with the brain’s perception of starvation and hunger. For these reasons 5-HTP has been used as an appetite suppressant in obese persons. 5-HTP which increases serotonin levels can suppress appetite at low doses (50 - 200 mg) if taken one half hour before meals.
During clinical trials in obese subjects, the intake of 5-HTP caused a voluntary
decrease in caloric intake of both carbohydrates and fats. A significant loss of
weight occurred, due to a voluntary decrease in calorie intake and not because
of a restrictive diet.
5-HTP and Excessive Coughing
5-HTP has been shown to act as a central modulator of the cough reflex. A study in the United Kingdom concluded that 5-HTP exerts an inhibitory influence over excessive coughing in humans at peripheral and possibly central sites.
Amino acid-vitamin interactions are important when considering therapeutic strategies. Pyridoxine is the most important vitamin for amino acid metabolism because it is a cofactor for the transaminases, which metabolise amino acids. Riboflavin and nicotinic acid are the next most important vitamins in amino acid metabolism.
Conclusion
The scheduling of
tryptophan as an S4 drug does not apply to the next step in serotonin
metabolism, 5-HTP.
Many studies have examined the effects of 5-HTP on animals and humans at doses
as high as the equivalent of several grams per day. All studies concluded that
there appears to be no toxicity. Overly high doses may be associated with
drowsiness.
Warning: Do not purchase any 5-HTP product where peak X may have been used in the manufacturing process. Refer to the FDA discussion: http://vm.cfsan.fda.gov/~1rd/tp5htp.html
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