Magnesium is physiologic NMDA receptor antagonist. It will stabilized NMDA receptor and prevents influx of calcium and sodium ion. It has been studied that serum magnesium level is low in patients with chronic pain. Several studies has been done and shown that Magnesium has a significant effect in neuroprotection and membrane stabilization. Blocking the NMDA receptor will prevent activation of first order neurons in periphery or second order neurons in dorsal horn of spinal cord and then higher pain pathways to third order neurons and centers of the pain perception. Topical, oral and more effectively intravenous administration of magnesium has been used widely in treatment of chronic pain. There are limitations of intravenous administration of magnesium secondary to systemic cardiovascular side effects.