Best 5-HTP (5-hydroxytryptophan)
60 Capsules
Each capsule
contains:
5-hydroxytryptophan..........100mg
Excipients:
rice powder, magnesium stearate
Suggested Adult Use: Take one
capsule two or three times daily.
5-HTP Enhanced with
Vitamins B6 & C
120 Veggie Caps
Each capsule
contains:
Vitamin C..........200mg
Vitamin B6(pyridoxine
hydrochloride)..........15mg
5-hydroxy
L-tryptophan..........100mg
Excipients: Cellulose (veggie
cap), rice powder, magnesium stearate, silicon
dioxide.
Suggested Adult Use: Take one capsule two or three
times daily with or without food.
Notice: Not to be used
concurrently with MAO inhibitors, selective serotonin reuptake
inhibitors (SSRIs) or other anti-depressant medications. It
should also not be used by individuals taking any of the
category of medications known as "triptans".
Free of "Peak X"
as verified by assay.
Caution: Keep out of reach of
children.
What is 5-HTP?
5-HTP
(5-hydroxytryptophan) is a naturally-occurring metabolite of the
essential amino acid tryptophan. 5-HTP for use in dietary
supplements is derived from the seeds of the Griffonia
simplicifolia plant.
Metabolism and absorption of
5-HTP
5-HTP (5-hydroxytryptophan) is formed by the addition of
a hydroxyl group (-OH) to the 5 carbon of the indole ring of
tryptophan. Conversion of tryptophan to 5-hydroxytryptophan is
catalyzed by the enzyme tryptophan hydroxylase.1 5-HTP functions
as the precursor for serotonin, and is converted to serotonin in
a pyridoxal phosphate (vitamin B6) dependent reaction catalyzed
by the enzyme L-amino acid decarboxylase.2
Synthesis of
serotonin in the brain requires an adequate supply of either
tryptophan or 5-HTP as precursors. The supply of tryptophan
available for conversion to 5-HTP depends on a number of
factors, including nutritional status and competition between
tryptophan and other amino acids for transport across the blood
brain barrier.
Disturbances in the serotonin metabolic
pathway may disrupt central nervous system functions which
utilize serotonin as a neurotransmitter.2 Administration of
5-HTP bypasses the conversion of tryptophan to 5-HTP. 5-HTP
readily crosses the blood brain barrier and becomes available
for serotonin synthesis. Serotonergic neurons (nerve cells
stimulated by serotonin) regulate sleep, appetite, nociception
(the perception of pain), and aggressive behavior.2
Serotonin
is metabolized to 5-HIAA (5-hydroxyindolacetic acid) which is
its primary breakdown product.3 The concentration of 5-HIAA in
cerebrospinal fluid is used as an indicator of serotonin
turnover in the CNS serotonin level. Psychiatric patients have
been found to have low levels of 5-HIAA in the CNS fluid,
suggesting serotonin deficiency.3
5-HTP is readily absorbed
by the mucosal cells of the gastrointestinal tract. In one study
using five subjects, systemic absorption of 5-HTP in combination
with carbidopa averaged 69.2 percent.4 Another absorption study
found that carbidopa enhanced the increase in serum 5-HTP
concentration 5 to 15 fold.5 In this study, a single dose of
5-HTP increased the plasma level of 5-HTP only slightly, whereas
5-HIAA increased 9-20 fold. This suggests that the gut mucosa
has a storage capacity for 5-HTP, and that plasma increases
occur after maximum capacity is reached.5
Observed Effects of
5-HTP Administration
Improves Well-Being in Depressed
Persons
Serotonin in the central nervous system is recognized
as a causative factor in some depressed persons.6,7 A
comprehensive review of seven open and seven controlled clinical
studies found that oral consumption of 5-HTP improved mental and
emotional status in 60 to 70 percent of depressed people. The
results varied from "modest" to "marked."8 Dosages ranged from
50 to 300 mg daily.
The accumulated evidence is inconclusive
as to whether 5-HTP is more effective combined with
decarboxylase inhibitors than when taken alone. Many of the
early trials used the combination, and this has been a
frequently used therapeutic strategy for reducing conversion of
5-HTP to serotonin outside the CNS. It is generally accepted
that a large portion of absorbed 5-HTP is metabolized to
serotonin in peripheral tissues before it can enter the
brain.8
Peripheral conversion of 5-HTP to serotonin would
theoretically limit the usefulness of oral 5-HTP for improving
CNS functions and mental health. However, trials in which 5-HTP
was given alone do show benefits. A small open trial in which 25
people were given 5-HTP either alone or with a decarboxylase
inhibitor found no difference in effectiveness.9 Thirteen of the
patients had "very good" or "good" improvement, 8 had
"moderate," and in 4 out of the twenty-five the results were
judged to be "poor."
A more recent randomized double-blind
study compared the efficacy of oral 5-HTP (100 mg T.I.D.,
without a decarboxylase inhibitor) to that of fluvoxamine, a
selective serotonin reuptake inhibitor.10 (SSRIs block the
reabsorption of serotonin by postsynaptic receptors, thus
increasing the available supply of serotonin in the synaptic
cleft.) The two were found to be equally effective, and 5-HTP
was better tolerated. It should be noted that 5-HTP was given in
the form of enteric-coated pH-sensitive capsules which dissolve
in the small intestine, thus preventing conversion of 5-HTP to
serotonin in the stomach.
In contrast to MAO inhibitors and
SSRIs, medications which act by blocking normal physiologic
functions, 5-HTP supports normal function in its role as a
serotonin precursor. Correcting serotonin deficiency has been
called a "functional-dimensional approach" in the treatment of
depression.10
Improves Sleep Quality
Studies have shown that
5-HTP influences the quality of sleep by increasing REM (rapid
eye movement) sleep. Administration of 5-HTP in the evening
prior to bedtime has been shown to increase the duration of REM
sleep and decrease the amount of non-REM sleep.11,12
5-HTP–A
Free-radical Scavenger
The OH group which is added to
tryptophan in the formation of 5-HTP gives 5-HTP antioxidant
properties.13 (Compounds such as vitamin E and flavonoids derive
their free-radical quenching ability from OH groups, which
donate electrons to oxidants.) 5-HTP quenches a variety of
free-radicals. This is in contrast to tryptophan, which is
sensitive to oxidation.
Adverse effects of 5-HTP
Oral
administration of 5-HTP in clinical studies has resulted in
gastrointestinal disturbances such as nausea, vomiting and
diarrhea. According to a review by Byerley, et. al. these
effects are tolerated by most patients and tend to lessen over
time.8 Side effects are more marked with higher doses, and may
be reduced by the use of enteric-coated, pH sensitive capsules
or tablets.8,10.
*This statement has not been evaluated by
the Food and Drug Administration. This product is not intended
to diagnose, treat, cure or prevent any disease.
Scientific
References:
1. Pike, R.L., Brown, M.L. Nutrition: An Integrated
Approach. NY: Macmillan Pub. Co.; 1986:626-28.
2. Peters, J.C.
Tryptophan nutrition and metabolism: An overview. Advances in
Experimental Medicine and Biology 1991;294:345-349.
3. van
Pragg, H.M. Central monoamine metabolism in depressions. I.
Serotonin and related compounds. Comprehensive Psychiatry
1980;21(1):30-43.
4. Magnussen, I., Neilsen-Kudsk, F.
Bioavailability and related pharmacokinetics in man of orally
administered L-5-hydroxytryptophan in steady state. Acta
pharmacol. et toxicol. 1980;46:257-62.
5. Magnussen, I.,
Jensen, T.S., Rand, J.H., Van Woert, M.H. Plasma accumulation
and metabolism of orally administered single dose
L-5-hydroxytryptophan in man. Acta pharmacol. et toxicol.
1981;49:184-89.
6. van Pragg, H.M. Korf, J. 5-hydroxytryptophan
as an antidepressant. Journal of Nervous and Mental Disease
1974;158(5):331-37.
7. van Pragg, H.M. Management of depression
with serotonin precursors. Biological Psychiatry
1981;16(3):291-310.
8. Byerley, W.F. et. al.
5-Hydroxytryptophan: A review of its antidepressant efficacy and
adverse effects. Journal of Clinical Psychopharmacology
1987;7(3):127-37.
9. 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;20:28-35.
10. Pöldinger, W.,
Calanchini, B., Schwarz, W. A functional-dimensional approach to
depression: Serotonin deficiency as a target syndrome in a
comparison of 5-hydroxytryptophan and fluvoxamine.
Psychopathology 1991;24:53-81. 11. Zarcone, V.P. Hoddes, E.,
Smythe, H. Oral 5-hydroxytryptophan effects on sleep. in
Serotonin and Behavior, edited by Barchas, J., Usidin, E., NY:
Academic Press; 1973:499-505.
12. Wyatt, R.J., et. al. Effects
of 5-hydroxytryptophan on the sleep of normal human subjects.
Electroencephalography and Clinical Neurophysiology
1971;30:505-09.
13. Simic, M.G. Al-Sheikhly, M. Jovanovic, S.V.
Inhibition of free radical processes by antioxidants-tryptophan
and 5-hydroxytrytophan. Bibl Nutra Dieta 1989;43:288-96.
©
2004 Doctor's Best, Inc. Revised
04/2004
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