The oral sphingosine 1-phosphate receptor (S1PR) modulator fingolimod functionally antagonizes S1PR hereby blocking lymphocyte egress from secondary lymphoid organs to the peripheral blood circulation. This results in a reduction in peripheral lymphocyte counts, including potentially encephalitogenic T cells. In patients with relapsing multiple sclerosis fingolimod has been shown to be an effective treatment. In phase 2 and phase 3 studies fingolimod-treated patients had reduced disease activity clinically and in MRI. Although severe infectious complications occurred in single cases treated with fingolimod, the frequency of overall infections was comparable in fingolimod-treated patients and controls. Overall, in clinical studies fingolimod was well tolerated and had a favorable safety profile. In follow-up studies with continuous fingolimod, treatment showed sustained efficacy while being well tolerated.