Desvenlafaxine is a serotonin-norepinephrine reuptake inhibitor (SNRI) that modulates neurotransmitter levels in the central nervous system, potentially reducing neurogenic inflammation and pain signaling associated with cluster headaches. By increasing synaptic concentrations of serotonin and norepinephrine, it may help regulate pain perception and provide prophylactic relief for cluster headache episodes through its neuromodulatory effects.