1. Fish oil
Surprisingly, fish oil supplements can cause bleeding due to their high levels of omega-3 fatty acids, which have natural blood-thinning properties. Omega-3, especially EPA and DHA, help reduce inflammation and are beneficial for heart health, but they can also lead to blood clotting.
"One of the effects of high doses of fish oil is that it can thin the blood by inhibiting platelet aggregation, which is the process that helps your blood clot," says Dr. Taher Saifullah, founder of Spine & Pain Institute Los Angeles. "This means that if you’re taking fish oil and also using blood thinners like warfarin, your risk of bleeding could increase." He recommends talking to your doctor before starting fish oil, especially if you're on other medications.
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2. Ginkgo biloba
Ginkgo’s active ingredients, particularly flavonoids and terpenoids, improve blood flow by dilating blood vessels and reducing platelet aggregation. Although these effects are beneficial, they can also increase bleeding risk, especially when mixed with blood-thinning medications.
"It has anticoagulant properties, which means it can make it harder for your blood to clot, increasing the risk of bleeding. If you’re considering Ginkgo, especially if you take medications like aspirin or other anticoagulants, it’s essential to discuss this with your healthcare provider to avoid any serious interactions," states Dr. Safiullah.
3. Garlic supplements
Garlic supplements are another one that contain compounds that naturally thin the blood. While it’s beneficial for cardiovascular health, excessive amounts or concentrated garlic supplements can increase the risk of bleeding.
"They can interfere with blood clotting mechanisms, especially when combined with anticoagulant medications. If you're taking garlic in supplement form, it’s wise to check with your doctor to ensure it’s safe for you, particularly if you’re on medications that affect blood clotting," notes Dr. Safiullah.
4. Vitamin E
Vitamin E supplements can cause bleeding primarily because of their anticoagulant properties, which can interfere with the blood clotting process. When taken in high doses, this vitamin can increase bleeding, especially in individuals who are already on blood-thinning medications like warfarin and aspirin.
"Consuming vitamin E from a balanced diet or taking moderate supplement doses is generally safe for most people. However, high doses can hinder blood clotting by interfering with platelet function and reducing the body's ability to utilize vitamin K, a crucial nutrient for blood clotting. This combination can increase the likelihood of bleeding," says David Nazarian, M.D., Diplomate American Board of Internal Medicine.
5. Turmeric supplements
While turmeric has a range of health benefits, you may want to be careful if you decide to add it to your diet as a supplement. "In my practice, I've seen cases where presumed harmless supplements caused significant interactions," explains Dr. Ralph Waldo. "One patient, already on blood thinners, experienced prolonged bleeding due to unsupervised turmeric intake, underscoring the importance of custom medical advice. It highlights why thorough professional consultation, especially in integrative medicine, is indispensable for safe supplement use."