EFFICACY: MONOTHERAPY AND ADJUNCTIVE USE FOR ANXIETY AND DEPRESSION
SUGGESTED BUT UNPROVEN USES: FIBROMYALGIA, INSOMNIA, BINGE EATING ASSOCIATED
WITH OBESITY, CEREBELLA ATAXIA, AND CHRONIC HEADACHES
DRUG INTERACTIONS
SIDE EFFECTS
CONTAMINATION
DOSAGE
RESEARCH
Tryptophan, an amino acid, is a precursor of serotonin and has been used since the 1970s
to increase brain levels of serotonin. Small, mostly uncontrolled studies have shown
positive effects in some depressed patients, but others have not. The reason proposed for
the equivocal effects is that tryptophan by itself may be insufficient to boost serotonin
levels. On the other hand, using tryptophan (or its active, metabolized form, 5-HTP) as an
adjunct to supplement standard antidepressants has been more successful. Tryptophan was
banned by the FDA from 1991-2002. 5-HTP has been found effective for relief of anxiety in
preliminary double-blind studies.
5 - HTP (5-hydroxy-L-tryptophan) is a modern variant, now extensively marketed in the
United States. 5-HTP is created in the body from tryptophan and in turn is used by the body
to create serotonin. 5-HTP may thus offer the advantage of bypassing the conversion
process, which requires the enzyme tryptophan hydroxylase, which in turn can be affected
by stress and other factors. Supplemental 5-HTP is created from the seeds of the Griffonia
simplicifolia plant and is often combined with St. John’s wort.
