Tyrosine and phenylalanine serve as metabolic precursors in the direction of the synthesis of mescaline. Tyrosine can both go through a decarboxylation by way of tyrosine decarboxylase to create tyramine and subsequently undertake an oxidation at carbon 3 by a monophenol hydroxylase or first be hydroxylated by tyrosine hydroxylase to variety L-DOPA