Is omeprazole safe to take if I’m allergic to shrimp or other shellfish?

Omeprazole is generally considered safe for people with shrimp or other shellfish allergies because it does not contain shellfish-derived ingredients and shellfish allergy does not create a known cross‑reaction risk with omeprazole. ^[1] However, omeprazole can rarely cause its own allergic reactions, so it should be avoided if you have ever reacted to omeprazole or other proton pump inhibitors (PPIs). ^[2]

Key point

• Shellfish allergy does not by itself contraindicate omeprazole. Product labels warn against use only in people allergic to omeprazole (or other PPIs) or to any component of the capsule. ^{[2] [3]}
• Check the ingredient list. Common inactive ingredients include lactose, gelatin, and other excipients; these are not shellfish-derived. ^[1]

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What the official labels say

• Omeprazole is contraindicated in anyone with known hypersensitivity to substituted benzimidazoles (the drug class) or to any component of the formulation. ^[2] This includes serious reactions such as anaphylaxis, angioedema, bronchospasm, interstitial nephritis, and hives. ^[2]
• Nonprescription and prescription labels advise not to use if you are allergic to omeprazole and to stop and seek help if a rash, blistering, or other signs of a severe skin reaction occur. ^{[4] [5]}

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Ingredients and shellfish concerns

• Typical inactive ingredients in delayed‑release capsules include crospovidone, glyceryl dibehenate, hypromellose, lactose monohydrate, methacrylic acid copolymer, silicon dioxide, talc, titanium dioxide, triethyl citrate, and a gelatin capsule shell; some products may also contain sodium lauryl sulfate. ^[1] None of these are shellfish-derived. ^[1]

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Allergy to PPIs vs. shellfish allergy

• A shellfish allergy is usually due to tropomyosin proteins in crustaceans and does not imply allergy to omeprazole or other PPIs. ^[6]
• True allergy to PPIs is uncommon but documented; symptoms can include hives/angioedema and, rarely, anaphylaxis. ^[7] In small clinical series, some people allergic to omeprazole tolerated another PPI (for example, lansoprazole), while others reacted to multiple PPIs, showing that cross‑reactivity patterns can vary. ^{[8] [7]}

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Practical guidance

• If you have only a shellfish allergy and have never reacted to omeprazole or other PPIs, omeprazole can generally be used while watching for any new symptoms such as rash, swelling, wheezing, or severe dizziness. ^{[4] [2]}
• Do not take omeprazole if you have had any prior allergic reaction to omeprazole or another PPI, or if you know you are allergic to any listed inactive ingredient in the specific product you plan to use. ^{[2] [1]}
• If you need a PPI and have a history suggesting PPI allergy, an allergist can consider skin testing and/or supervised oral challenge to identify a tolerated alternative. ^{[8] [7]}

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Red‑flag symptoms that need urgent care

• Stop the drug and seek immediate help for signs of a severe reaction: widespread hives, swelling of lips/tongue/throat, trouble breathing, dizziness/fainting, or severe skin blistering/rash. ^{[4] [2]}

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Summary

• Shellfish allergy alone is not a reason to avoid omeprazole, and omeprazole products do not list shellfish-derived ingredients. ^[1]
• Only avoid omeprazole if you are allergic to omeprazole/other PPIs or to any of its components, and monitor for rare allergic reactions when starting therapy. ^{[2] [4]}