Introducing Soy to Your Baby

Soy shows up in tofu, edamame, and many packaged foods. It can be introduced around 6 months in soft, age-appropriate forms and is an easy plant protein for babies.

Safe ways to serve soy

Soft silken or firm tofu, mashed or cut into strips
Well-cooked, mashed edamame

⚠️ Serve tofu and edamame soft and in age-appropriate pieces. Mash edamame to reduce choking risk.

Want age-by-age prep, nutrition, and storage? See the full soy food guide →

Signs of an allergic reaction

Hives or welts, unless they are only around the mouth with nothing else
Swelling of the lips, face, or eyes
Vomiting
A change in behavior, like becoming very unsettled
If any of these show up soon after a food, stop that food and get medical advice right away
Call emergency services right away for swelling of the tongue, swelling or tightness in the throat or trouble swallowing, difficult or noisy breathing, wheezing, a cough that keeps going, or a hoarse voice
Also call emergency services for swelling of the lips or face that comes on suddenly or keeps spreading, vomiting that repeats, hives that spread over the body, skin or lips that turn pale or blue, a baby who goes floppy or is hard to wake, or signs in more than one part of the body, like hives plus vomiting

General tips for introducing allergens

Most babies are ready for solids around 6 months, once they can sit with support and show interest.
Introduce one new allergen at a time and let its watch window pass, about 3 days, before the next, so any reaction can be traced to a single food.
Once an allergen is tolerated, keeping it in the diet regularly is part of current guidance.
Offer allergens earlier in the day (not right before bed) so you can watch for any reaction.
If your baby has severe eczema or a known food allergy, talk to your pediatrician before introducing peanut or egg.

New to allergens? Read the complete introduction guide →

About soy allergy

General, sourced background, not medical advice and not based on your baby's logs. Your allergist decides what is right for your child, especially on cross-reactivity.

How common: About 0.4% of US infants and young children are allergic to soy. (FARE)
Outgrowing it: Most children outgrow it: in one allergy-clinic study, about half had outgrown it by age 7 and about 7 in 10 by age 10. (research study)
Cross-reacts with: Soy is a legume, but most people with a soy allergy can still eat other legumes like chickpeas, kidney beans, and lentils, so ask your allergist before cutting them. Peanut is different: in one allergy-clinic study, most children with a soy allergy also had a peanut allergy, so ask your allergist how to introduce peanut. (ASCIA) (research study)

Frequently asked questions

When can babies have tofu?

Tofu can usually be offered around 6 months as a soft first food and is a gentle way to introduce soy.

Sources

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Let the app track the big 9 for you

Log a first taste and YummyYucky opens a watch window on that allergen, tells you when it is clear to start the next, and keeps the ones that go fine in rotation. Free.

Start the allergen tracker, free

Last updated September 2026. Next review December 2026. How we write these: built from current published guidance from the AAP, CDC, FDA/EPA, NIAID, WHO, and other pediatric and public-health authorities, with sources cited on the page. See our editorial and medical policy for how we research, source, and update these, and how we double-check the food advice.

This is general information, not medical advice, and is not individualized for your baby. Always talk to your pediatrician about your baby's diet, introducing allergens, and any reaction. In an emergency, contact emergency services.

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