"Blood thinner" is a common name for medicines that help reduce the formation of blood clots. They do not all work in the same way, so advice for one medicine does not automatically apply to another.
Some medicines are anticoagulants, which affect proteins involved in clotting. Others are antiplatelet medicines, which affect platelets, the blood cells that help form clots. Examples of both are discussed below.
A pharmacist can check the exact medicine against your supplement and the rest of your routine. Bring the name and dose of each prescription, over-the-counter medicine and supplement you take, even if you use it only occasionally.
Warfarin
If you take warfarin, speak with your prescriber, pharmacist or anticoagulation clinic before starting or changing a magnesium supplement. They can advise whether you need a change to your schedule or follow-up blood testing.
Some clinical guidance advises separating magnesium and warfarin because magnesium may interfere with warfarin absorption. Patient.info recommends at least two hours between them, but that guidance does not establish how every magnesium glycinate product affects warfarin. Evidence from studies of different magnesium forms is mixed. Ask your care team what timing is appropriate for your exact formula. (patient.info)
Warfarin is commonly monitored with a blood test called the international normalized ratio, or INR. The test helps your care team assess how long your blood takes to clot. Ask whether they want to check it after you start, stop or change a supplement.
Vitamin K also matters with warfarin. You do not need to avoid foods containing it, but keeping your intake consistent helps your care team manage your medication. Tell them before starting or stopping a supplement that contains vitamin K.
Apixaban and Other Direct Oral Anticoagulants
A Drugs.com interaction check found no listed interaction between apixaban, sold as Eliquis, and magnesium glycinate. The same resource cautions that a missing listed interaction does not necessarily mean none exists. (drugs.com)
That finding is specific to those two ingredients. It does not clear a combination magnesium product with added vitamins or herbs, and it does not replace a review of your other medicines.
If you take another direct oral anticoagulant, such as rivaroxaban or dabigatran, ask your pharmacist to check that medicine by name. Do not assume a result for apixaban applies to every blood thinner.
Aspirin and Clopidogrel
Aspirin and clopidogrel work differently from anticoagulants. If you take either as part of your prescribed routine, ask your healthcare provider or pharmacist to review the magnesium product before you add it.
The review should cover the whole label, not only magnesium glycinate. It should also include any other medicine you take that affects bleeding or clotting.
Key Takeaway: The medication name and the full supplement formula matter more than a general claim that magnesium is safe with "blood thinners."
