The primary objective of this study is to evaluate the analgesic efficacy of a maximum single dose of two tablets of Aleve (2 x naproxen sodium 220 mg; total dose 440 mg) as compared to two tablets of Tylenol Extra Strength (2 x acetaminophen 500 mg; total dose 1000 mg) for the treatment of menstrual cramping pain associated with primary dysmenorrhea.