Selepryl or Cyprenil as it is also commonly known, is a liquid that contains selegiline citrate (otherwise known as deprenyl). Selegiline was first synthesized by Hungarian Professor Joseph Knoll in his Budapest laboratory in 1961. It forms part of a class of medications – monoamine oxidase inhibitors or MAOIs – that act as powerful antidepressants. There are two forms of MAOIs –type A (MAO-A) inhibitors and type B (MAO-B) inhibitors. Selegiline is a selective MAO-B inhibitor and breaks down dopamine into compounds which are then excreted. By inhibiting MAO-B, the breakdown of dopamine is reduced, thereby increasing the amount of dopamine available. Why is Dopamine so Important? Although dopamine is found in many parts of the body, it is found in the greatest concentration in a part of the brain called the basal ganglia. The basal ganglia (a mass of grey matter at the base of the brain that plays an important role in regulating bodily movement) includes the substantia nigra and it is t