Verapamil, a calcium channel blocker, is commonly used for cluster headache prophylaxis by reducing neurogenic inflammation and modulating neurotransmitter release in the trigeminal system. Its mechanism involves blocking L-type calcium channels, which decreases smooth muscle contraction and inhibits neuronal excitability, thereby reducing the frequency and intensity of cluster headache episodes. The medication helps stabilize cerebrovascular tone and interrupt the underlying pathophysiological processes contributing to cluster headache attacks.