OBJECTIVE: Severe traumatic brain injury (TBI) has a major role in mortality 
rate among the other types of trauma. The aim of this clinical study was to 
assess the effect of progesterone on the improvement of neurologic outcome in 
patients with acute severe TBI.
METHODS: A total of 76 patients who had arrived within 8h of injury with a 
Glasgow Coma Score≤8 were enrolled in the study. In a randomized style 38 
received progesterone (1mg/kg per 12h for 5 days) and 38 did not.
RESULTS: There was a better recovery rate and GOS score for the patients who 
were given progesterone than for those in the control group in a 3-months 
follow-up period (50% vs. 21%); subgroup analysis showed a significant 
difference in the percentage of favorable outcome between the two groups with 
GCS of 5-8 (p=0.03).
CONCLUSION: The use of progesterone may significantly improve neurologic outcome 
of patients suffering severe TBI up to 3 months after injury, especially those 
with 5≤GCS≤8, providing a potential benefit to the treatment of acute severe TBI 
patients. Considering this drug had no significant side effects, so progesterone 
could be used in patients with severe TBI as a neuro-protective drug.