Fingolimod was first synthesized in the early 1990s as part of an extensive program of chemical derivatization of myriocin, with the goal of creating a novel immunosuppressant that would be more potent and less toxic in vivo. Fingolimod's mechanism of action in multiple sclerosis (MS) is not known with certainty. Fingolimod was initially developed to prevent allograt rejection after demonstration that it was effective in a variety of animal transplantation models, including kidney, heart, pancreatic islet cells and skin. Fingolimod was approved by the Food and Drug Administration (FDA) to reduce relapses and disability progression in relapsing forms of MS. Fingolimod's generally good safety profile and tolerability, including oral route of administration, make fingolimod an attractive treatment option for patients with relapsing forms of MS. Better delineation of the mechanisms leading to both the beneficial and adverse effects of fingolimod is necessary to develop more effective and better-tolerated compounds.