Does losartan contain any soy-derived ingredients, and is it safe to take if I have a soy allergy?

Losartan tablets do not list soy or soy-derived ingredients on their official U.S. labels, and they are generally considered safe for people with soy allergy; however, specific inactive ingredients can vary by brand and manufacturer, so it’s wise to verify the exact product you are taking. ^{[1] [2]}

What’s in brand-name Cozaar (losartan)

• The brand formulation (Cozaar) lists the following inactive ingredients: microcrystalline cellulose, lactose hydrous, pregelatinized starch (corn starch), magnesium stearate, hydroxypropyl cellulose, hypromellose, and titanium dioxide; some strengths may also contain carnauba wax. ^{[1] [3]}
• None of these listed excipients are soy or soybean oil. ^{[1] [3]}
• The official Cozaar label reiterates the same inactive ingredients across 25 mg, 50 mg, and 100 mg tablets. ^{[2] [4]}

What about generic losartan?

• Many generic products use similar excipients (e.g., cellulose, lactose, corn starch, magnesium stearate, film-coating polymers), but the exact list can differ by manufacturer and strength. ^{[2] [5]}
• Because excipients can vary, the safest approach is to check the specific manufacturer’s label for your tablet’s National Drug Code (NDC) to confirm there is no soy-derived component. ^{[2] [5]}

Soy allergy considerations with medications

• Drug excipients are typically “inactive,” but people with food allergies can occasionally react if an excipient is derived from an allergenic source and contains residual proteins. ^{[6] [7]}
• Studies measuring proteins in excipients show that some food-derived excipients (for example, certain oils or lactose) can contain trace proteins, which in susceptible individuals could theoretically trigger symptoms; this is why verifying excipients matters for food-allergic users. ^[8]
• Importantly, the standard U.S. losartan labels do not list soybean oil or soy-based excipients, and there is no routine contraindication to losartan use solely due to soy allergy. ^{[9] [10]}

Practical safety steps

• Ask your pharmacist to print the exact inactive ingredient list for your specific losartan product and strength; pharmacists can identify the manufacturer via the pill imprint and NDC. ^[11]
• If you have a history of severe, immediate reactions (anaphylaxis) to trace soy proteins, consider selecting a product whose label you have personally reviewed and keep it consistent (same manufacturer) to avoid formulation changes. ^{[8] [6]}
• If you notice any signs of an allergic reaction after starting a new lot such as hives, swelling, wheezing, or throat tightness seek urgent care and bring the bottle for ingredient verification. ^{[6] [7]}

Bottom line

• Based on official labeling, brand-name Cozaar and commonly referenced losartan tablets do not contain soy or soybean-derived ingredients. ^{[1] [2]}
• For most people with soy allergy, losartan is considered a reasonable and safe option, provided you confirm the excipients of the specific product you receive. ^{[9] [11]}

Quick reference: Cozaar inactive ingredients

Tablet	Inactive ingredients listed	Soy present on label
Cozaar 25/50/100 mg	Microcrystalline cellulose, lactose hydrous, pregelatinized starch (corn), magnesium stearate, hydroxypropyl cellulose, hypromellose, titanium dioxide; may contain carnauba wax	Not listed

Would you like me to help check the specific manufacturer and inactive ingredients for the exact losartan tablet you have by looking up its pill imprint or NDC?