Magnesium may be an effective agent for treating hypoxic-ischemic brain injury. It can protect brain cells through multiple mechanisms: (1) it is an NMDA receptor blocker that reduces excitotoxicity, (2) it attenuates biochemical changes like ATP depletion and acidosis, and (3) it has anti-inflammatory and vasodilatory properties that can reduce edema. Magnesium's diverse physiological roles allow it to counteract the various pathways of injury better than other agents used singly. More research is still needed but magnesium shows promise as a "master drug" for brain resuscitation.