L-Dopa, also known as levodopa, and sold as a prescription medicine under names such as Larodopa, is an amino acid precursor to the neurotransmitter dopamine. L-Dopa is an antiparkinsonian agent commonly prescribed to people with Parkinson's Disease.
In pharmaceutical products, it is frequently paired with carbidopa, which decreases peripheral metabolism of levodopa, causing a greater amount to cross the blood-brain barrier. This combination is sold under brand names such as Sinemet and Parcopa.
Legality and Availability
In the United States, United Kingdom, Australia, and other countries, L-Dopa is unscheduled prescription-only medicine. However, the compound is naturally occurring in plants such as mucuna pruriens, and is available over-the-counter as a dietary supplement in the United States and elsewhere.
L-Dopa is effective at treating and slowing the progress of Parkinson's Disease. In healthy individuals, it has effects similar to other dopaminergic stimulants, including improved working memory and wakefulness.
At least one study has found L-Dopa may increase penile girth.
A euphoric effect is possible from L-Dopa, but to lesser extent than classical amphetamines.
L-Dopa increases levels of dopamine in the brain, and is associated with unwanted effects such as compulsive gambling. At high doses, it has been known to cause stimulant-induced psychosis.