A needle-free device for delivering a 6 mg fixed dose of sumatriptan into subcutaneous tissues has been developed and approved for the acute treatment of migraine and cluster headache in the US and some EU countries. In a pivotal registration study in healthy adult volunteers, a single dose of needle-free subcutaneous sumatriptan 6 mg demonstrated bioequivalence to a single dose of traditional, needle-based subcutaneous sumatriptan 6 mg when delivered into the abdomen or the thigh, but not the arm. In a noncomparative, multicentre, phase IV study, the administration of (one or two doses of) needle-free subcutaneous sumatriptan 6 mg consistently provided rapid and sustained relief from migraine pain and associated symptoms during the treatment of up to four migraine attacks over a period of up to 60 days among current triptan users. Moreover, the use of needle-free subcutaneous sumatriptan was associated with a significant improvement in treatment satisfaction in these patients who were less than 'very satisfied' with their usual symptomatic therapy. Needle-free subcutaneous sumatriptan was generally well tolerated in the phase IV study. Although the overall adverse event profile of the needle-free delivery system was similar to that previously reported for the needle-based delivery system, it was associated with a numerically higher incidence of administration/injection-site reactions in clinical trials that enrolled healthy adult volunteers.