General Description
5-Hydroxytryptophan, or 5-HTP, (also called L-5-hydroxytryptophan
or levo-5-hydroxytryptophan) is a natural compound manufactured
in the body as a metabolite of L-tryptophan, an amino acid found
in a variety of dietary proteins. Supplemental 5-HTP is derived
from the seeds of the West African medicinal plant Griffonia
simplicifolia.
Health applications
Primary functions
The body uses 5-HTP to produce serotonin, a neurotransmitter involved
in sleep, moods, appetite, pain control, and other body functions.
Because 5-HTP is inactive in the body until it is converted into
serotonin, the physiological effects of 5-HTP supplementation
depend upon its ability to increase serotonin production.
Depression
Because alterations in serotonin metabolism appear to be an important
factor in the development of depression, researchers have been
investigating the therapeutic potential of 5-HTP in depressed
patients. Preliminary trials indicate that 5-HTP may help improve
symptoms in some forms of depression,1-4 with the best
results obtained in patients with anxious-agitated depressive
syndromes and patients with acute endogenous depression.4
While these small-scale studies show promise, larger, long-term
trials are needed to confirm their results.
Fibromyalgia
Scientists have observed low serum serotonin levels in patients
with fibromyalgia, compared to healthy controls.5,6
Studies indicate that supplemental 5-HTP may improve symptoms
(including depression, anxiety, insomnia, number of tender points,
pain intensity, and fatigue) in many fibromyalgia patients,7-9
presumably by increasing serum serotonin levels.
Migraine
headaches
Abnormal serotonin metabolism has been implicated in the development
of migraine headaches,10,11 suggesting a possible role
for 5-HTP in migraine therapy. Clinical trials have shown 5-HTP
to be effective in reducing the frequency12-14 and
severity12-15 of migraine attacks in some subjects.
Although 5-HTP was less effective than some other migraine treatments,13,15
its relatively low incidence of side effects (which were generally
mild and transient 14) suggests it could be useful
for individuals sensitive to other migraine medications.
Insomnia
Because serotonin is believed to play a significant role in sleep
patterns, it has been suggested that increasing serotonin levels
by supplementing serotonin precursors such as L-tryptophan and
5-HTP may improve sleep in some insomniacs. In the 1980s, tryptophan
supplements gained popularity as natural sleep aids, and several
studies showed improved sleep latency (the time it takes to fall
asleep) in insomniacs given L-tryptophan.16-22 Presumably,
5-HTP would have a similar effect because L-tryptophan must be
converted into 5-HTP before it can be reduced to serotonin. However,
large-scale studies on the efficacy of 5-HTP in treating insomnia
are lacking.
Weight
loss
Investigations into the role of neurotransmitters in regulating
appetite suggest 5-HTP may be an effective weight-loss aid. Placebo-controlled
trials showed significant weight loss and reduction of carbohydrate
intake in obese subjects given 5-HTP.23-25 The efficacy
of 5-HTP in promoting weight loss in nonobese subjects has not
been demonstrated.
Dosage/toxicity
Doses of 5-HTP used in clinical trials have ranged from 100-400
mg/day for migraine to 900 mg/day for weight loss, and this dosage
range appears to be safe for most people. Reported side-effects,
including gastrointestinal upset, headache, sleepiness, and anxiety,
are usually mild. 5-HTP may produce harmful interactions with
some drugs, including many antidepressants and appetite suppressants.
People taking antidepressants or other prescription medications
should consult a physician before using 5-HTP. |
