Alopecia is usually presented as patchy, no scarring hair loss. It seems to be a hormonal imbalance or an immune mediated disease, whereas genetic predisposition, environmental and psychological factors may be involved in its etiology. Many treatments of alopecia disease have been widely applied, but their side effects are also well known. The purpose of this study is to demonstrate efficacy and safety of a food supplement containing medicinal plant extracts, amino acid and vitamin complex on the prevention of hair loss in human. A total of 20 subjects aged between 29-50 years with subjective hair loss complaint were recruited for this study. Each subject took 1 g/day supplement for 3 months. 5-Scale self-assessment test, hair loss count and measurement of hair thickness were conducted to evaluate the effect of supplement on the improvement of hair loss. Subjective hair loss was decreased and hair damage and thickness were improved in self-assessment test. After 3 months of supplementation, hair loss counts were decreased (P<0.05) while hair thickness was increased(P<0.001) significantly. There was no side effect observed during the study. These results suggest that the supplement consist of medicinal plant extracts, amino acid and vitamin complex might be useful for the improvement of hair loss with no significant side effects.