The gender differences in pharmacokinetics of a combination tablet of niacin extended-release/simvastatin were evaluated in healthy Chinese volunteers. Thirty-six healthy male and female volunteers were enrolled in the study receiving a single oral dose of niacin extended-release/simvastatin 1,000/20 mg. The results indicated that the systemic exposure of simvastatin hydroxy acid and the total urine excretion of niacin were significantly higher for females compared with those for males, and the T max of niacin in plasma was significantly shorter for males than that for females. There were no significant differences in the systemic exposure of simvastatin, niacin, and NUA in plasma between males and females.