L-DOPA is used to increase the levels of dopamine in the body and so is used in the treatment of Parkinson’s disease. After entering the central nervous system, L-DOPA is converted to dopamine by L-amino acid decarboxylase. Pyridoxal phosphate is required for this reaction to occur, and so is generally administered along with L-DOPA as pyridoxine.

In order to bypass any adverse side effects related to sole L-DOPA administration, a peripheral DOPA decarboxylase inhibitor   is also prescribed, often through medicines containing carbidopa .

Levodopa can be taken in the form of a tablet or a capsule.