5 HTP Clinical Evidence
Journal of Neural Transmission Ceci F, et al.
International Clinical Psychopharmacology.
Alternative Medicine Review.
- 5-HTP is well absorbed from an oral dose; 70% makes it to the bloodstream.
- 5-HTP crosses the blood-brain barrier and increases production of serotonin by the
- central nervous system.
- 5-HTP has been shown effective in human clinical trials in treating numerous health conditions.
Pharmacology and Therapeutics.
- Scientific support for the use of 5-HTP to treat depression is not definitive, because
- of insufficient numbers of large-scale, double-blind, placebo-controlled studies. Also,
- many studies tested 5-HTP in combination with other ingredients.
- However, seven out of eleven small, double-blind, placebo-controlled studies found
- 5-HTP to outperform placebo, indicating some efficacy in the treatment of depression.
- While very high levels of serotonin can cause anxiety and seizures, no cases of
- serotonin syndrome associated with 5-HTP have been reported.
- More studies of efficacy and safety are needed.
5-HTP Mechanism of Action
Research has shown that when levels of 5-HTP are increased, levels of serotonin — a brain chemical necessary for a positive mood — are also increased. That’s because 5-HTP is the direct precursor to serotonin. Tryptophan, another ingredient used to boost serotonin, is the direct precursor to 5-HTP. Therefore, 5-HTP provides a more direct route for increasing serotonin production.