This is a prospective, randomized, open-label, delayed-start clinical investigation evaluating the safety and efficacy of the Walther System, a Class IIa investigational medical device delivering intra-nasal mechanical stimulation (INMEST), as a preventative treatment for migraine. A total of 110 adults (18-65 years) with a history of migraine will be randomized 1:1 into two groups: Group A (early treatment) and Group B (delayed treatment). The study includes baseline assessments, in-clinic device training, and home-based self-administered treatments every second day for six weeks. The primary outcome is the change in monthly migraine days during the primary treatment comparison period. Secondary outcomes include headache days, migraine intensity, duration, rescue medication use, patient-reported outcomes, device compliance, and safety. The study will be conducted at one site in Sweden.