l-DOPA, also known as levodopa and l-3,4-dihydroxyphenylalanine, is an amino acid that is made and used as part of the normal biology of humans, as well as some animals and plants.
Levodopa or dihydroxyphenylalanine (DOPA) is a large neutral amino acid (LNAA) that is the precursor for catecholamines: dopamine, norepinephrine, and epinephrine. ... The DOPA required only decarboxylation by the enzyme aromatic amino acid decarboxylase (AAAD) to be converted into dopamine.
L-DOPA burst onto the clinical scene in the late 1960s as a miracle drug, unlocking or awakening patients immobilized for years or decades by the crippling and progressive neurodegenerative disease. Its debilitating side effects became apparent with equal swiftness.
Thus, l-DOPA is used to increase dopamine concentrations in the treatment of Parkinson's disease and dopamine-responsive dystonia. Once l-DOPA has entered the central nervous system, it is converted into dopamine by the enzyme aromatic l-amino acid decarboxylase, also known as DOPA decarboxylase.