Male patients (16-65 year old) who admitted to a university hospital intensive care unit with moderate to severe Traumatic Brain Injury (TBI) were enrolled using consecutive sampling. Inclusion criteria were GCS of 4-12, enteral nutrition started in 24 hours after admission, having mechanical ventilation. The procedure and protocol of the study was approved by the Ethic Committee of Tehran University of Medical Sciences. Written informed consent were obtained from patient's relative. After recording anamnesis, patients were examined physically. Urgent actions were done, simple radiography were taken from skull and CT-scan were performed if it is necessary. Patients who had internal bleeding, obvious fractures in their limbs, history of metabolic or psychiatric disorder, alcohol or drug dependency, underlying diseases, or vegetarian diet would be excluded from the study. Patients' base line information including age, sex, vital signs, GCS, clinical symptoms at time of reception, diagnosis based on CT-scan, type of treatment (medicinal or surgical) and surgical area of body were recorded. patients were then divided into two experimental groups: (1) receiving epigallocatechin gallate (EGCG) supplement (case group, n = 15) and (2) receiving placebo (control group, n = 15). EGCG supplement was in the form of 400 mg oral capsules with a purity of 80% catechin. EGCG powder of each capsule was dissolved in 10 ml deionized water and given to patients via gavage (1 capsule per day) for a week. Placebo group only received 10 ml of deionized water via gavage for a week. During that week, GCS of patients was recorded by a neurosurgery resident who was blinded. For seven days, vital signs, glucose, hematocrit, haemoglobin, platelet were recorded every day at 9:00 a.m. Duration of the connection to mechanical ventilation was also recorded.