OstroVit - Histidine is an amino acid...
The amino acid tryptophan in powder form is a natural relaxant.
Dietary supplement OstroVit - Tryptophan is a precursor of serotonin, it is also an intermediate for the production of melatonin.
The amino acid L-tryptophan helps to maintain a relaxed state of the body, normalize sleep, give a positive mood and improve immune function.
BioTech Dietary Supplement - L-Tryptophan - tryptophan is an essential amino acid that performs numerous functions in the body, including as a precursor of serotonin and melatonin.