Soy is the FDA's third most commonly declared major food allergen after milk and wheat, and it is also one of the most heavily processed — which means it appears in an unusually wide range of derivative forms on ingredient lists. Under FALCPA, any of these derivatives that contain soy protein must be labeled as 'soy,' but knowing the derivative names helps you spot them when you are scanning quickly or dealing with a label that uses the ingredient name rather than the allergen declaration.
What FALCPA requires manufacturers to declare
Under FALCPA, a food that contains soy — or any ingredient derived from soy that still contains soy protein — must declare soy either in the ingredient name ('soy sauce,' 'tofu') or in a plain-language 'Contains: Soy' statement after the ingredient list (FDA). Highly refined soybean oil is the main exception: the FDA exempts it from allergen labeling because refining typically removes the protein that triggers allergic reactions. However, cold-pressed, expeller-pressed, and extruded soybean oil are not exempt — these retain more protein and must be declared.
Soy ingredient names to watch for
The following ingredient names indicate the presence of soy, per FDA allergen guidance and FARE: edamame (immature soybeans), miso (fermented soy paste), natto (fermented soybeans), shoyu (soy sauce), tamari (gluten-free soy sauce), tempeh (fermented soy cake), tofu (soy curd), soy protein isolate and soy protein concentrate (used in protein shakes, meat substitutes, nutrition bars), textured vegetable protein / TVP, textured soy protein, textured soy flour, hydrolyzed soy protein, soy lecithin (an emulsifier — see note below), soybean oil (unrefined forms only), yuba (soy milk skin). Manufactured foods that contain 'vegetable protein,' 'vegetable broth,' or 'natural flavors' may also derive from soy, though FALCPA's declaration requirement still applies whenever soy protein is present.
The soy lecithin exception and controversy
Soy lecithin is an emulsifier derived from soy that appears in chocolate, baked goods, and many processed foods. FDA allergen guidance notes that soy lecithin is derived from soybean oil and typically contains only trace soy protein. However, FALCPA still requires it to be labeled as containing soy, and FARE notes that most people with soy allergy can tolerate soy lecithin — but not all. As with any allergen tolerance question, that is a conversation for a physician, not a label guide. The label will show soy lecithin (or 'lecithin' with 'Contains: Soy'), giving you the signal regardless.
Hidden Allergen Names Decoder
Paste an ingredient list to highlight all soy-derived names
Open Hidden Allergen Names Decoder →Scan for soy, tofu, edamame, tamari, miso, tempeh, TVP, soy protein, and hydrolyzed soy protein. Highly refined soybean oil is exempt; unrefined forms and soy lecithin must be declared. The 'Contains: Soy' line is the fast-check — if it is not there, soy-derived protein is not an ingredient.