What is 3-methoxy-4-hydroxyphenylacetic acid (HVA)

One of the key substances, or metabolites, produced through the action of both catechol-o-methyltransferase (COMT) and monoamine oxidase (MAO) in series on dopamine. This substance is also called homovanillic acid, commonly known as HVA. High levels of HVA are correlated to low levels of dopamine. comt-inhibitor drugs taken to treat Parkinson’s disease slow or suppress HVA production to extend the period that dopamine remains active in the brain.