Rasagiline is a selective monoamine oxidase type B (MAO-B) inhibitor used to treat Parkinson’s disease. It works by increasing dopamine levels in the brain, which helps improve motor symptoms such as tremors and stiffness. Rasagiline is typically used as monotherapy in the early stages of Parkinson’s disease or as an adjunct to levodopa in more advanced stages. The 0.5 mg dosage is commonly prescribed when initiating treatment or adjusting the dose based on the patient's response.