Pizotifen is a prophylactic treatment taken every day in the hope of reducing frequency of migraine attacks. A good result is a 50% reduction in attack frequency. Start with 0.5mg every evening (10-12 hours before planning to get up). Start with 0.5mg; maximum is 4.5mg. It often causes weight gain and sleepiness. Some experts (e.g. NICE) regard it as of unproven efficacy, I think it can work well in young people but is less effective in adults. Treatment duration is 3-12 months. It is useful to keep a diary to assess response.