Based on NIH | Is it safe to eat shrimp while taking warfarin, or could it interact and change my INR?

Eating shrimp in typical amounts is generally considered safe while taking warfarin, and there is no evidence that shrimp itself meaningfully raises or lowers INR for most people. ^[1] Warfarin’s well‑known food interactions are driven mainly by vitamin K content and a short list of specific foods or beverages, and shrimp is not on those lists. ^[1]

Why diet matters with warfarin

Warfarin works by blocking vitamin K’s role in making clotting factors, so sudden changes in vitamin K intake can make INR go up or down. ^[2] Because of this, guidance focuses on keeping vitamin K intake consistent and not making big day‑to‑day swings in vitamin K–rich foods. ^{[3] [4]}

Vitamin K and seafood

Vitamin K is found at high levels in leafy green vegetables and certain plant oils; these are the foods most likely to reduce warfarin’s effect if eaten in large or fluctuating amounts. ^{[5] [6]} Shrimp and most shellfish are low in vitamin K compared with leafy greens, so they are not expected to significantly impact INR when eaten in normal portions. ^[5]

What’s on the official caution lists

Authoritative guidance consistently highlights items like leafy greens (kale, spinach, broccoli), certain vegetable oils, cranberry products, alcohol, grapefruit, green tea, black licorice, and some botanicals as potential warfarin interaction concerns. ^{[1] [7]} Shrimp is not included among commonly cited foods that interact with warfarin. ^[1]

Practical tips for eating shrimp on warfarin

• Keep your overall diet steady from week to week; consistency matters more than avoiding specific low‑vitamin K foods like shrimp. ^{[3] [4]}
• If you serve shrimp with very vitamin K–rich sides (for example, large portions of kale salad) or cook regularly with high‑vitamin K oils, try to keep those amounts consistent as well. ^[5]
• If you make a significant change in your diet pattern (for example, starting a new meal plan or adding multiple servings of vitamin K–rich foods), let your care team know and consider an extra INR check. ^{[8] [4]}

Other seafood and fish oil considerations

Standard seafood intake is not a problem for warfarin users, but concentrated fish oil supplements have been listed as items to use cautiously because they may affect bleeding, especially if combined with other blood‑thinning agents; discuss supplements with your clinician and monitor INR if you start or stop them. ^{[6] [8]}

INR monitoring still comes first

Warfarin has a narrow therapeutic window, so routine INR monitoring is essential, and extra checks are reasonable after any notable changes in diet, medications, or supplements. ^[8] Keeping diet steady including seafood habits helps maintain a stable INR. ^[3]

In summary, shrimp itself is not known to interact with warfarin in a way that meaningfully changes INR, and it can generally be included in a consistent diet while you continue regular INR monitoring. ^{[1] [3]}