Siponimod is used to prevent episodes of symptoms and slow the worsening of disability in adults with relapsing-remitting forms (course of disease where symptoms flare up from time to time) of multiple sclerosis (MS; a disease in which the nerves do not function properly and people may experience weakness, numbness, loss of muscle coordination, and problems with vision, speech, and bladder control). Siponimod is in a class of medications called sphingosine l-phosphate receptor modulators. It works by decreasing the action of immune cells that may cause nerve damage.