Creatine supplementation improves performance, but is it safe? Double-blind placebo-controlled study

BACKGROUND: creatine represents a natural supplement and ergogenic aid for sport performance, but there are several concerns regarding its safety for health. The present double-blind placebo-controlled study evaluated the effect of creatine monohydrate supplementation on a panel of blood and urine health indicators in resistance training practitioners. METHODS: Eighteen males performing resistance training three times per week were supplemented with 0.3 g/kg per day creatine monohydrate for 7 days and compared with matched controls supplemented with dextrosol. Blood and urine samples were collected pre- and 30 days post-supplementation to evaluate 41 biochemical parameters and renal function. RESULTS: Creatine monohydrate supplementation did not cause adverse events and, as expected, promoted an increase of the performance and body weight. No modification of red blood cells parameters, white blood cells profile, blood lipid profile, metabolic and urine markers, hepatic and renal function were observed in the supplemented group. CONCLUSIONS: Despite the expected weight increase, the creatine monohydrate supplementation is safe for health and no detrimental effects on different organs and physiological systems were observed in our cohort of volunteers.