Vydura was shown to be more effective than placebo (a dummy treatment) at treating migraine in three main studies involving a total of around 3,500 adults. Patients with a migraine attack causing moderate to severe headache recorded the level of pain two hours after treatment using a 4-point Likert scale (0 = no pain, 1 = mild pain, 2 = moderate pain, 3 = severe pain).

On average across the three studies, 20% of patients taking Vydura were headache pain-free after two hours, compared with 12% on average for those taking placebo. Vydura was also effective at treating other migraine symptoms such as photophobia (abnormal sensitivity of the eyes to light), phonophobia (abnormal sensitivity to sounds) or nausea (feeling sick): on average, around 36% of patients taking Vydura were free from one of the above symptoms two hours after treatment, compared with around 27% of those taking placebo.

Another study showed that Vydura is effective at reducing the number of days patients suffer from migraines. The study involved 747 adults who had between 4 to 18 migraine attacks a month; patients took Vydura or placebo every other day for up to 12 weeks. Those treated with Vydura had on average 4.3 fewer days with migraines during the last 4 weeks of the study, compared with 3.5 fewer days for patients on placebo.