The 9 common baby food allergens
Nine foods cause most allergic reactions in the U.S.: peanut, tree nuts, egg, milk (dairy), soy, wheat, sesame, fish, and shellfish. The current advice is to introduce each of them early and keep the ones that go well in the diet. Tap any allergen for a parent-friendly guide.
Peanut
the #1 to startGuide →Tree nuts
all 7, one hubGuide →Egg
well-cooked firstGuide →Dairy
yogurt & cheeseGuide →Soy
tofu & edamameGuide →Wheat
cereals & pastaGuide →Sesame
thinned tahiniGuide →Fish
cooked & flakedGuide →Shellfish
cooked, choppedGuide →01Which allergens come first?
Peanut and egg are the two most-studied first allergens — the evidence for introducing them early (around 6 months for most babies) is strongest. After those go well, work through tree nuts, dairy, soy, wheat, sesame, fish, and shellfish one at a time. There's no single "correct" order beyond starting with peanut and egg.
02The method that applies to all nine
- One new allergen at a time, in a baby-safe form, so a reaction is easy to trace.
- Offer a small taste earlier in the day, then watch for about two hours.
- Wait 2–3 days before introducing the next new allergen.
- Keep the winners in rotation — about twice a week — so tolerance sticks.
New to all of this? Start with the step-by-step guide to introducing allergens, grab the free schedule, and learn how to spot a reaction.
Frequently asked questions
What are the 9 major food allergens?
Which allergen should I introduce first?
How many allergens can I introduce at once?
One plan for all nine