A new study in this month's British medical journal Lancet suggests that a daily dose of 81 mg of aspirin for cardiovascular health is effective for people weighing less than 154 pounds, but if you are heavier, you may need a higher dose for the aspirin to be effective. Cardiologist Dr. Dan Anderson at UNMC says this will open up more research to determine whether doctors should recommend the higher dose to a level from 325-500 mg per day for people who weigh more than 154 pounds.