Biologique Recherche L-Tyrosine is an amino acid that’s a precursor to dopamine and norepinephrine. Griffonia simplicifolia contains an amino acid called L-5-HTP (hydroxytryptophan), a precursor of serotonin. It helps improve brain activity. Chromium is a natural and essential trace element that contributes to maintaining normal blood sugar levels and ensuring the normal metabolism of macronutrients.