According to About.com, you should take one Aleve every 8 to 12 hours. It is also permissible to take two Aleve in the first hour. It is harmful to take more than two Aleve in an 8- to 12-hour period and more than three in a 24-hour time frame.
About.com states that the higher the dosages of Aleve, the higher a person’s chances of suffering a heart attack or stroke. It is recommended to take the smallest dose possible to relieve painful symptoms of backaches, menstrual cramps, arthritis, toothaches and headaches. Each Aleve, whether in gelcap, capsule, tablet or caplet form, is 200 mg naproxen and 20 mg sodium. A doctor can determine the safe amount of these two ingredients for each patient.