Objective: To assess biochemical and histopathological hepatotoxic effect of popular energy drink (POWER HORSE) Design: randomized controlled trial study. Materials and Methods: 40 adult albino rats were randomly distributed into two groups, each group formed of twenty rats, group (I), received tap water, group (II), received POWER HORSE, 3.8ml/100g orally, every day for continuous twenty one (21) days. All animals were scarified. Blood samples were gained for biochemical analysis. Histopathological examination of liver was performed through Hematoxylin and Eosin staining. Results: POWER HORSE energy drink treated group showed significant increase in AST, ALT and ALP levels when compared to the CONTROL group. Group received POWER HORSE energy drink showed detrimental effects of on liver histopathological examination with severe degenerative changes in liver tissue.  Conclusions: POWER HORSE energy drink showed high degree of detrimental effects on both liver functions and histopathological examination of liver tissue revealing the hazardous effect og energy drinks on health.