Homovanillic acid-13C,d3 (Vanilacetic acid-13C,d3) is 13C and deuterium labeled Homovanillic acid (HY-N0384). Homovanillic acid (Vanilacetic acid) is a dopamine metabolite found to be associated with aromatic L-amino acid decarboxylase deficiency, celiac disease, growth hormone deficiency, and sepiapterin reductase deficiency[1].