Selegiline (l-deprenyl, Eldepryl or Anipryl [veterinary]) is a drug used for the treatment of early-stage Parkinson's disease and senile dementia. In normal clinical doses it is a selective MAO-B inhibitor, however in larger doses (>20 mg in a typical adult) it loses its specificity and also inhibits MAO-A. Dietary restrictions are common for MAOI treatments, however, since selegiline is selective for MAO-B, special dietary restrictions for lower doses have been found to be unnecessary. The drug was researched by Joseph Knoll. Selegiline is most closely related to the phenylethylamines. The only difference between the two classes of drugs is the attachment of a propargyl group (three carbons with a triple bond between the second and third carbon) to the nitrogen.