Donald G. Stein, from Emory University (Georgia, USA), and colleagues propose that injected or infused progesterone be considered as a treatment option for head trauma and central nervous system injuries. Citing 100 preclinical studies and two clinical trials showing the hormone’s beneficial effects on brain and central nervous system injuries including traumatic brain injury, the team suggests that progesterone protects against oxidative stress and immune/inflammatory rejection reactions, as well as regulates neuronal development., mechanisms by which the hormone may hold promise in the treatment of traumatic and degenerative disorders of the brain and central nervous system.  The team concludes that:  "Given its relatively high safety profile, its ease of administration, and its low cost and ready availability, this hormone and its metabolites should be considered as a viable treatment option -- especially because, in brain injury, so little else is currently available."