Levodopa is a naturally occurring dietary supplement found in certain kinds of herbs. The most common plant source of Levodopa marketed in this manner is Stizolobium cochinchin ensis (Lour) and Mucuna Pruriens. Some animals including humans make it via biosynthesis from the amino acid L-tyrosine. L-DOPA is synthesized from the amino acid L-tyrosine in the mammalian body and brain, it is the precursor to the neurotransmitters dopamine, collectively known as catecholamines. L-DOPA can be manufactured and in its pure form is sold with the INN levodopa. Aside from its natural and essential biological role, L-DOPA is also used for the Parkinson's disease and dopamine-responsive dystonia.