5-HTP is the precursor to Serotonin
5-HTP is the precursor to serotonin, the neurotransmitter sometimes touted to be responsible for happiness. 5-HTP is a simple way to increase brain serotonin levels by bypassing the rate-limiting step, and users increase brain serotonin.
It's a compound which gets converted into serotonin in the brain.
Serotonin is one of the principal neurotransmitters involved in happiness and anti-depression.
It has been used with success to restore serotonin levels in those that may suffer from decreased serotonin levels, such as the depressed and those with high levels of body inflammation (typically seen in metabolic syndrome).
Some of the potential benefits are:
Increased Serotonin levels
Increase in satiety and reduced binge eating
Better sleep
Better stress response
Better panic/anxiety response
Increased Serotonin levels
Supplementation of 5-HTP has been shown to be more effective than tryptophan supplementation alone. This additional benefit of 5-HTP supplementation arises because 5-HTP bypasses the cell's L-tryptophan's own self-regulation on the IDO enzyme, in which it upregulates the activity of IDO to maintain body homeostasis of tryptophan and it bypasses the tryptophan hydroxylase enzyme, which is the rate limiting step in serotonin biosynthesis.
5-HTP is very reliable in increasing serotonin levels. 5-HTP is used as a clinical test to judge the potency of drugs that affect serotonin levels (by pairing an experimental drug with 5-HTP to induce 'serotonin syndrome', or serotonin toxicity, one can see how much that drug exacerbates serotonin biosynthesis or bio-availability by seeing how much of a 5-HTP dose is required to induce the syndrome; the lower dose indicative of higher drug potency.
Increase in satiety and reduced binge eating
5-HTP can increase satiety (sensation of fullness) rather than reducing appetite (preventing the desire to eat), although the end result is less food intake.
At least one study using an extract of Griffonia simplicifolia (10.24mg giving 2.56mg 5-HTP) taken in three hits, five times a day (40mg 5-HTP total), by 20 overweight or obese females (non-depressive and without eating disorders) for 4 weeks has noted an increase in satiety and reduced binge eating tendencies; the increase in satiety was said to account for the improved weight loss results seen in the experimental group when both were given weight loss advice and diets. This has been noted elsewhere to increase satiety (and vicariously through that, body weight) over 2 months in a similar demographic of women.
In 19 obese females given either placebo or 8mg/kg (weight not actually given, only BMI between 30-40 for women) daily for 5 weeks without any concurrent dietary recommendations, 5-HTP treatment was associated with a decrease in appetite and food intake (resulting in weight loss) without significantly affecting mood state. This study noted that food intake was reduced from an average of 2,903kcal to 1,819kcal (62% of baseline) while placebo only reduced calories to 80%, and the 0.5kg weight loss in placebo was outperformed by a near 1.5kg loss in 5-HTP. These weight loss effects have been noted with 750mg 5-HTP over 2 weeks in overweight diabetics and over 12 weeks in obese persons given 900mg 5-HTP daily (58% of baseline intake); this latter study had a 6-week trial without a diet (in which significant weight loss was only noted at week 6) followed up by co-administration with a diet where weight loss proceeded to reach an additional 3.3kg over the subsequent 6 weeks:] this latter study is duplicated in Medline.
Additionally, most studies are in exclusively females which may have more significance with interventions pertaining to serotonin metabolism; only one study mentioned above was conducted in men as well but appears to suggest that it benefits both genders.
Better sleep
A nutrient combination of GABA and 5-HTP (amongst other ingredients such as Valerian and Cocoa polyphenols) has been noted to decrease the time required to fall asleep with concomitant improvements in sleep duration and quality as assessed by the Pittsburgh Sleep Quality Index (PSQI).
Better stress response
One study investigating romantic stress that looked at non-depressed youth who went through a recent breakup and were given 60mg of Griffonica Simplicifonia (12.8mg 5-HTP) twice a day for 6 weeks in an open-label study noted reductions in perceived romantic stress when measured at the 3-week mark with no further improvement at 6 weeks (there was no control nor placebo group in this study).
Better panic/anxiety response
Persons who suffer from Panic disorders may be more susceptible to serotonergic imbalances, with tryptophan depletion (thought to be a reliable model to reduce serotonin) causing greater susceptibility to panic attacks.
Serotonin appears to be associated with panic attacks. Although studies that have used tryptophan depletion techniques in humans do not necessarily induce a panic attack it appears it may sensitize the body by an increase in neurovegetative panic symptoms and increased anxiety which suggests that serotonin is protective against panic attacks, at least acutely. A study in 24 unmedicated panic disorder patients and normal participants given 200mg 5-HTP prior to a 35% CO2 test (used to induce a panic attack-like response) noted that the test was able to induce panic attack in both panic disorder patients and normal persons and that 200mg 5-HTP was protective in both conditions but to a greater degree in persons suffering from panic disorders. This has been replicated with cholecystokinin-4 induced panic attack with 200mg 5-HTP in otherwise healthy persons.
Expanding upon the possible anti-panic effects of 5-HTP, one study using 2mg/kg 5-HTP to children (3.2-10.6 years of age) at bedtime for 20 days noted that 5-HTP was associated with beneficial response (more than 50% reduction in night terror frequency) of 93.5% of children relative to 28.6% in placebo. Oddly, 6 months after the initial supplementation period the 5-HTP group still reported less sleep terrors (83.9% reporting improvement).
