<qa>  What is the amount of aspirin per day?8. Regularly take greater than 660 mg of aspirin per day. This is greater than two tablets of 325 mg regular strength aspirin or greater than one tablet of 500 mg of extra strength aspirin per day. If one has been taking aspirin for heart or blood vessel protection regularly for at least one month before hisher first screening visit, heshe will remain on the same amount of medicine throughout the study. The following amounts are acceptable: 