Double Stacker King: Allergens at a Glance
The honest verdict
Double Stacker King · Burger King
The Double Stacker King is a double cheeseburger with two beef patties, two slices of American cheese, stacker sauce, and a sesame seed bun. The allergen profile is anchored by wheat (bun), milk (cheese), egg (mayo in sauce), and sesame (bun seeds). Soy appears in the stacker sauce (soybean oil) and the bun. Peanut, tree nut, fish, and shellfish are not typical ingredients. The Double Stacker King differs from the Whopper (which adds tomatoes, lettuce, onions, and ketchup) and a standard cheeseburger (single patty, no stacker sauce). Cross-contact from shared grills and prep surfaces is always possible. Always confirm with your specific Burger King location before ordering.
Allergen details change and vary by location. This is a general guide — always confirm with the restaurant before ordering. Not official or medical advice.
Key facts
The Double Stacker King contains two slices of American cheese, making milk a primary allergen in this sandwich.
The stacker sauce contains mayonnaise, which introduces egg as an allergen — ordering without sauce removes it.
Burger King's sesame seed bun contains both wheat and sesame, making it a double-allergen source for those with gluten and sesame allergies.
FDA — Food Allergen Labeling and Consumer Protection Act (FALCPA)
Every major allergen, one clear grid
Each of the nine major allergens marked for Double Stacker King at Burger King — Contains, May contain (cross-contact or varies), or Free. Anything we couldn't confirm defaults to "may contain," because a shared kitchen can't be ruled out without the restaurant's official menu.
| Allergen and notes | Status |
|---|---|
Milk Two slices of American cheese are standard on the Double Stacker King. Milk is a primary ingredient in American cheese. Removing the cheese is the only way to make this item milk-free. | Contains |
Egg The stacker sauce contains mayonnaise, which is made with egg. This is the primary source of egg in the sandwich. Ordering without stacker sauce removes this allergen. | Contains |
Wheat / Gluten The sesame seed bun is wheat-based. There is no standard gluten-free bun option at Burger King. The bun is the sole source of wheat in this sandwich. | Contains |
Soy Soybean oil is used in the stacker sauce and may appear in the bun. Highly refined soybean oil is FDA-exempt from allergen labeling and tolerated by most with soy allergy. Those with severe soy sensitivity should confirm ingredients with the restaurant. | May contain |
Peanut Peanut is not an ingredient in the Double Stacker King or its components. Cross-contact is very unlikely in Burger King's kitchen environment. | Free |
Tree Nut Tree nuts are not an ingredient in this sandwich or its components. | Free |
Fish Fish is not an ingredient in the Double Stacker King. Burger King does not typically fry fish items in the same prep area as burgers. | Free |
Shellfish Shellfish is not an ingredient in this sandwich and is not typical in Burger King's kitchen. | Free |
Sesame The bun is topped with sesame seeds. This is a direct source of sesame. Sesame is also present in some Burger King bun varieties. There is no standard sesame-free bun option. | Contains |
“May contain” means cross-contact is possible or the answer varies by location — not that the allergen is a listed ingredient. For a severe allergy, treat “may contain” the same as “contains” until the restaurant confirms otherwise.
Small changes that remove an allergen
Simple modifications that can take an allergen off your double stacker king. Always name your allergy when you order and ask staff to confirm — a modification only helps if the kitchen prepares it separately.
Order without cheese
Order without stacker sauce
Request a lettuce wrap instead of the bun
Ask for a plain burger without the bun and sauce
A modification lowers exposure but doesn't erase cross-contact from shared fryers, grills, or prep surfaces. For a severe allergy, confirm the prep with a manager before you eat.
Read this before you order
Cross-contact & severe allergies
A “free of” mark on the grid above means the allergen isn't an ingredient — it doesn't mean the item was made in an allergen-free kitchen. Two things matter most:
Shared fryers & equipment
Burger King uses shared grills for all burger patties and shared prep surfaces for bun assembly. Trace amounts of milk, egg, wheat, and sesame from other menu items can transfer during cooking and assembly. The risk is the same as with the Whopper and other BK burgers — the Double Stacker King's additional cheese and sauce do not change the cross-contact dynamics. Ask staff about grill and prep practices at your specific location.
If your allergy is severe
For anaphylactic allergy to milk, egg, wheat, or sesame, confirm ingredient details and prep practices before ordering. The Double Stacker King is not guaranteed safe for any of these allergens without restaurant-level confirmation. Carry your epinephrine auto-injector. If you cannot confirm preparation details, a plain beef patty without bun or cheese is the safest option.
This guidance is general and can't account for how any single location prepares your food. The restaurant's staff and official allergen menu are the final word — when in doubt, ask, or choose something else.
Avoidance is not the only option for milk allergy
There is no FDA-approved immunotherapy for milk allergy. Some specialist centres offer milk oral immunotherapy off-label, and Xolair is approved to reduce the severity of reactions to accidental exposure across IgE-mediated food allergies.
Beyond that, oral immunotherapy in a specialist clinic raises reaction thresholds the most of any current approach, and sublingual immunotherapy raises them less but causes markedly fewer reactions and is easier to keep up over years. Neither makes any particular dish safe to eat, and an epinephrine auto-injector stays with you throughout.
A history of anaphylaxis, or severe or poorly controlled asthma alongside the food allergy, means this belongs with an in-person allergist rather than any remote service.
Frequently Asked Questions
Both share the same sesame seed bun (wheat + sesame) and beef patties. The Whopper adds tomatoes, lettuce, onions, pickles, ketchup, and mayonnaise — the mayonnaise is the egg source. The Double Stacker King uses stacker sauce (also egg-based from mayo) and two slices of American cheese (milk). The Whopper's cheese is optional; the Double Stacker King comes with cheese standard. Both have similar cross-contact profiles from shared grills.
Yes. The sesame seed bun is wheat-based, making this sandwich a direct source of gluten. There is no standard gluten-free bun option at Burger King. Removing the bun entirely (ordering a lettuce wrap or a bunless burger) is the only way to eliminate wheat/gluten from this item. Confirm that the beef patties are not seasoned with any wheat-based fillers.
Yes, you can request the Double Stacker King without cheese. This removes the milk allergen from American cheese. The sandwich will still contain egg (stacker sauce), wheat (bun), and sesame (bun seeds). Ask the staff to prepare it on a clean surface to minimize cross-contact from cheese residue on the grill or prep area.
The stacker sauce is a proprietary sauce that contains mayonnaise as a base ingredient. This means it contains egg, similar to Burger King's regular mayonnaise. Removing the stacker sauce removes the egg source from the sandwich. If you want a burger with a sauce alternative, ask about ketchup or mustard, which are typically egg-free.
Burger King does not currently offer a standard gluten-free or sesame-free bun option at most locations. The standard sesame seed bun contains both wheat and sesame. A lettuce wrap or bunless preparation is the only way to avoid both allergens. Confirm with your specific location whether they can accommodate a bunless order on a clean prep surface.
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Read moreFind out which foods you actually react to
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Please verify before ordering
Allergen info changes and varies by location
Recipes, suppliers, and preparation methods change often and differ between locations, so the details here can go out of date or not match your specific Burger King restaurant. Always confirm directly with the restaurant and check its official allergen menu before ordering. This page is a general research summary — it is not official information from Burger King, and it is not medical advice. If you have a food allergy, decisions about what is safe to eat should be made with the restaurant and, where relevant, your healthcare provider.
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