Methods of treating a subject with a traumatic central nervous system injury, more particularly, a traumatic brain injury, are provided. The methods comprise a therapy comprising a constant or a two-level dosing regime of progesterone. In one method, a subject in need thereof is administered at least one cycle of therapy, wherein the cycle of therapy comprises administering a therapeutically effective two-level intravenous dosing regime of progesterone. The two-level dosing regime comprises a first time period, wherein a higher hourly dose of progesterone is administered to the subject, followed by a second time period, wherein a lower hourly dose of progesterone is administered to the subject.