It is recommended that patients, on a blood thinner, confer with their doctor before starting any vitamin or supplement regimen. EyePromise has insignificant effect on blood thinners at the recommended dosage. Confusion occurs because Zeaxanthin and lutein are found in leafy green vegetables and doctors often tell patients taking blood thinners not to eat them. Leafy green vegetables contain Vitamin K, a contraindication for patients taking blood thinners. EyePromise does not contain Vitamin K. The amount of fish oil or Vitamin E in EyePromise is not at a level to be a concern for patients on blood thinners.