Can I take omega 3s if I’m on blood thinning medications? Sue Brennan: For people that are on anticoagulants like coumadin, warfarin or heparin, these are going to thin your blood and you have it already set up for a higher risk of potential bleeding. Addition of the omega 3s, and especially in some of the doses of 2 to 4 gram a day, may put a person at a higher risk for bleeding. So you definitely want to talk with your doctor or practitioner that’s ordered it for you and only on their advice would I take 2 to 4 grams a day of the omega 3.