The amino acids 5-hydroxytryptophan (5-HTP) and l-tryptophan are precursors of serotonin. 5-HTP is generally recommended over l-tryptophan because it crosses the blood-brain barrier at a higher rate, ...
Supplementation of naturally occurring amino acid, 5-Hydroxytryptophan, helped to improve sleep quality and the composition of good gut bacteria particularly in poor sleepers, indicating possible link ...