Hello Matthias: Sinemet is the trade name for a series of drugs combining L-dopa and carbi-dopa which are generic names for two dopamines. L-dopa is an amino acid normally manufactured by the body and residing in the brain. Interference in the body's manufacture of L-dopa resulting in a deficiency in the brain cells causes Parkinson Disease (PD). Therapy for PD normally consists of replenishing the missing amino acid with a synthetic L-dopa. Good luck.