Vestibular migraine is common and disabling, but evidence for preventive therapy has historically lagged behind evidence for conventional migraine. The INVESTMENT study was the first placebo-controlled randomized clinical trial to test a calcitonin gene-related peptide monoclonal antibody specifically in vestibular migraine. Adults with vestibular migraine or probable vestibular migraine were assigned to galcanezumab or placebo for three months. The trial assessed disease-specific disability, dizziness handicap and the number of symptomatic days. The results support a meaningful benefit of CGRP-targeted therapy in appropriately selected patients. Because this was a single-centre study with a relatively small sample and short treatment period, the findings should not be overgeneralised. Nevertheless, the trial is important because it provides controlled evidence for a treatment strategy that had previously been supported mainly by observational data. For HCPs, vestibular migraine should be treated as a distinct clinical problem rather than assumed to respond exactly like typical migraine. Diagnosis remains clinical, and vestibular rehabilitation and trigger management may still be relevant. The study opens an important therapeutic pathway for patients whose dizziness and vertigo remain disabling despite conventional preventive strategies.