Teriflunomide is primarily used in the treatment of multiple sclerosis (MS), specifically the relapsing forms of the disease. It works by inhibiting a mitochondrial enzyme involved in pyrimidine synthesis, which reduces the proliferation of activated lymphocytes that contribute to autoimmune damage in MS. By modulating the immune response, teriflunomide helps decrease the frequency of clinical relapses and slows the progression of physical disability. It is taken orally, offering a convenient option for long-term management. Due to its mechanism, it is considered a disease-modifying therapy (DMT) and is often prescribed for patients who require a well-tolerated, once-daily treatment. Monitoring of liver function and blood counts is recommended during therapy due to potential side effects.