Ozanimod is primarily used in the treatment of multiple sclerosis (MS), specifically for relapsing forms of the disease, including relapsing-remitting MS. It helps reduce the frequency of clinical relapses and slows the accumulation of physical disability. The drug also shows efficacy in managing moderately to severely active ulcerative colitis, an inflammatory bowel disease. By modulating the immune system—specifically through selective targeting of sphingosine 1-phosphate receptors—it reduces the migration of lymphocytes into inflamed tissues, thereby decreasing inflammation and autoimmune activity. Its oral formulation offers a convenient dosing option compared to injectable therapies, improving patient adherence. Due to its targeted mechanism, it has a favorable safety profile with fewer cardiovascular and hepatic side effects compared to earlier non-selective agents.