Interview with Steven R. Steinhubl, MD, author of Aspirin Dose for the Prevention of Cardiovascular Disease. Summary Points: 1. While aspirin is generally a safe drug and extremely effective, with more than 50 million US adults taking it every day for cardiovascular disease prevention, even a very small incidence of adverse effects can have major implications. Consistent with this, one study found that the most common medication leading to an adverse event requiring hospitalization was aspirin for cardiovascular disease prevention. 2. In terms of preventing heart attacks, strokes, or cardiovascular deaths, no clinical trial has identified an aspirin dose more efficacious than 75 to 81 mg daily. 3. Although there is no dose of aspirin that doesn't increase the risk of GI toxicity or bleeding, greater doses of aspirin are consistently associated with a greater risk. For example, in the United States alone, if everyone took 325 mg of aspirin daily instead of 81 mg, based on observational data, this could translate into nearly 1 million additional major bleeding complications a year.