In the US, 1.5 to 2.0 million civilians sustained a traumatic brain injury each year. The use of progesterone demonstrated a fifty percent reduction in mortality in patients treated compared to placebo. Functional outcomes were improved and reduced disability seen in patients suffering from moderate traumatic brain injury. The earlier patients received the drug the better the outcome as a means to try to prevent the brain from swelling immediately after the injury and the cascade of injury that occurs after that time. Neurosurgery and Trauma, March 2010).