a naturally occurring amino acid, a precursor to the neurotransmitter serotonin and an intermediate in tryptophan metabolism. It
5-HTP ( 5-Hydroxytryptophan): 10%/20%/30%/95%
5-Hydroxytryptophan or 5-HTP is a naturally occurring , a to the and an intermediate in . It is marketed in the and other countries as a dietary supplement for use as an , , and
5-Hydroxytryptophan is to (5-hydroxytryptamine or 5-HT) by the with the help of .
This reaction occurs both in nervous tissue and in the liver. 5-HTP crosses the , while 5-HT does not. Excess 5-HTP, especially when administered with , is thought to be metabolized and excreted.
The psychoactive action of 5-HTP is thought to derive from its effect on serotonin synthesis in tissue. It is believed that an artificially high supply of 5-HTP causes the brain's serotonin-producing neurons to increase production. Increased serotonin production then leads to increased serotonin release.
Research shows that co-administration with greatly increases 5-HTP levels. However, several studies have reported that 5-HTP is effective even without a peripheral decarboxylase inhibitor (e.g. carbidopa). Other studies have indicated the risk of a -like condition resulting from the combination of 5-HTP and carbidopa.
As a therapeutic supplement:
5-HTP, which is found in minute amounts in certain foods like and the white meat of , is often sold as an over-the-counter therapeutic supplement. In this case, it is usually sourced from the seeds of . 5-HTP in supplement form is typically sold in 50 mg or 100 mg or vegetarian capsules.
Because 5-HTP has not been thoroughly studied in a clinical setting, possible side effects and interactions with other drugs are not well known.
Due to the conversion of 5-HTP into serotonin by the liver, there is a significant risk of heart valve disease from serotonin's effect on the heart. In Europe, 5-HTP is prescribed with to prevent the conversion of 5-HTP into serotonin until it reaches the brain.