What happens when you take pumpkin seeds with warfarin?
Pumpkin seeds, also called pepitas, sit in the middle of the vitamin K nut and seed ranking. They are not as high as leafy greens but they contain more vitamin K than most other commonly eaten seeds. USDA data and warfarin patient guides such as the Harris Health System foods containing vitamin K reference put dried roasted pumpkin seeds at roughly 54 mcg of vitamin K per half-cup serving. That is enough to register on a warfarin patient's vitamin K budget if eaten frequently.
Warfarin works by blocking the vitamin K cycle in the liver. Any vitamin K-containing food can shift INR if intake changes substantially, with more vitamin K pushing INR down (more clotting tendency, less warfarin effect) and less vitamin K letting INR drift up (more bleeding tendency, more warfarin effect). The clinical guidance for warfarin is to stay consistent rather than to avoid vitamin K foods entirely.
Why is this important?
Pumpkin seeds are easy to eat in larger portions than people realize. A pre-portioned 1-ounce snack pack is fine. A handful from a big bag while watching TV can easily turn into a half cup, which then carries roughly 30 to 60 mcg of vitamin K. Eat that habit for a few days, then stop for a week, and you have introduced a sizable vitamin K swing that a tight-target warfarin patient may notice.
The seeds are also commonly used as a topping on salads, soups, granolas, and energy bars. That dispersion makes intake hard to track without paying attention. A salad with leafy greens already supplies vitamin K, and adding a sprinkle of pumpkin seeds on top adds incrementally to the total.
Pumpkin seeds contain some magnesium and zinc, both of which do not directly interact with warfarin but can affect absorption of other medications. They also contain small amounts of plant-form omega-3 with a mild antiplatelet contribution at very high doses, but this is negligible at snack-sized portions.
What should you do?
Treat pumpkin seeds like a vitamin K-containing food. The clinic's standard advice applies: keep weekly intake consistent. Pick a typical pattern (for example, a quarter cup three times a week as a salad topping) and stay roughly within that pattern.
Avoid binge-then-quit cycles. If you start a habit of a half-cup daily snack of pumpkin seeds, that is a meaningful dietary change and your clinic should know. They may want to check your INR four to six weeks after the change to confirm your dose is still right. The same applies in reverse if you have been a heavy pumpkin seed eater and stop suddenly.
Read labels on packaged products. Pumpkin seed butter, pumpkin seed protein, and pumpkin seed oil concentrate the vitamin K in different ways. Pumpkin seed oil in particular has been used in some supplement contexts at higher doses than most people would eat from raw seeds, so check intake when starting any pumpkin-based supplement.
Which specific products are affected?
This guidance applies to warfarin (Coumadin, Jantoven) and other vitamin K antagonists. Direct oral anticoagulants such as apixaban (Eliquis) and rivaroxaban (Xarelto) do not depend on vitamin K, so pumpkin seed intake does not affect those drugs through the same mechanism.
Pumpkin seed products to track include raw and roasted pepitas, salted pumpkin seeds, in-shell pumpkin seeds (much smaller serving size by volume), pumpkin seed butter, pumpkin seed protein powder, pumpkin seed oil, pumpkin spice trail mixes, and seasonal pumpkin baked goods topped with seeds. Pumpkin seed-based prostate health supplements should be discussed with your clinic since dosing can be much higher than a culinary snack.
The bottom line
Pumpkin seeds carry a moderate amount of vitamin K and can affect warfarin if intake swings dramatically. Keep your routine consistent, limit single servings to about a quarter cup, and let your anticoagulation clinic know if you adopt them as a major daily snack. There is no need to avoid pumpkin seeds, just to be consistent about how often and how much you eat.