Chronic pain affects millions in part because the body’s natural pain-inhibiting system often fails to function effectively. This project examines conditioned pain modulation (CPM), a behavioral measure of diffuse noxious inhibitory control, to understand how repeated engagement of this system may alter pain sensitivity and brain excitability over time. Impairment in CPM frequently appears in individuals who develop persistent pain, yet practical strategies to strengthen this mechanism remain limited. The study uses a randomized, controlled design with fifty healthy participants assigned to high-exposure or low-exposure CPM sessions. Each session combines CPM intervention, quantitative sensory testing, transcranial magnetic stimulation measures, and psychosocial assessments. Researchers evaluate whether repeated CPM exposure enhances intracortical inhibition or reduces cortical excitability and explore how sociocultural and psychological factors, including ethnic identity, resilience, and pain catastrophizing, shape individual responsiveness. Findings will clarify how endogenous pain inhibition can be strengthened and will inform future approaches to prevent or reduce chronic pain.