Sumatriptan nasal spray is a single-dose device that delivers 5 mg, 10 mg, or 20 mg of sumatriptan (dosage availability dependent upon country) in a 0.1 ml aqueous solution to one nostril. The efficacy and tolerability of sumatriptan nasal spray have been assessed in a number of studies. It has been demonstrated that administering sumatriptan as a divided dose in both nostrils confers no advantage over administration in a single nostril. It appears from these studies that sumatriptan nasal spray is rapidly effective (with an onset of efficacy as early as 15 min postdose). The 20 mg dose is superior to the lower doses (5 mg, 10 mg) in terms of both time to onset of efficacy and the extent of migraine symptom relief. Sumatriptan nasal spray is consistently effective in the treatment of multiple migraine attacks (with 67% of patients treated with the 20 mg dose responding in at least two of three treated attacks) and with long-term use for up to 1 year. Apart from a bitter taste, the adverse event profile of sumatriptan nasal spray is comparable to that of placebo.