Does a Protein Shake Interact With Warfarin?

If you suffer from heart disease or have a blood clot, your doctor may prescribe warfarin. Warfarin is a blood thinner, whose purpose is to prevent blood clots from forming or expanding in the blood vessels. Taking the correct dosage is important, because too little might not prevent clotting, while too much can lead to dangerous bleeding. Drinking protein shakes may contribute to a high-protein diet, which has been shown to negatively interact with warfarin, in some cases. Additionally, avoid protein shakes that contain added vitamin K. This vitamin is essential for blood clotting and can interfere with warfarin.

Drinking protein shakes regularly may cause an adverse interaction with warfarin. (Image: Stockbyte/Stockbyte/Getty Images)

Effects of a High-Protein Diet on Warfarin

A high-protein diet can interact with warfarin, a 2008 study published in "Pharmacotherapy." This occurs because excess protein may stimulate how quickly the body clears warfarin from your blood so that you require higher doses to get the same anti-clotting effect. Once your diet is normalized, however, the dose may be too high.

Protein Powder Shake Amount

Protein powders are food supplements that contain concentrated doses of protein and nutrients. Although drinking a protein shake occasionally will not raise your protein levels excessively, consuming it one or more times per day may push your total protein intake over the limit. Consuming 1/4 tablespoon or a 30-gram serving size of hemp protein powder provides 15 grams of protein, which is 30 percent of the daily recommended protein intake.