Peanut allergy in babies

Peanut is one of the most talked-about allergens for good reason: the landmark LEAP study found that introducing peanut early and keeping it in the diet dramatically reduced the chance of a peanut allergy developing in at-risk infants. For most babies, that means offering peanut in a safe form around 6 months rather than waiting.

Safe ways to serve peanut

Smooth peanut butter thinned with warm water, breast milk, or formula to a spreadable, non-sticky consistency
A spoon of thinned peanut butter stirred into oatmeal or yogurt
Peanut puff snacks that dissolve easily (for babies who can already manage them)

⚠️ Never give whole peanuts or thick globs of peanut butter. Both are choking hazards. Always thin it out and serve on a spoon or spread thinly.

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

Ready to start? Introducing peanut, step by step →

🛒 Our pick Want an easy option? A peanut puff (Bamba is the snack used in the LEAP study) is a simple way to get peanut in regularly. For babies under 7 months, or any baby not yet eating foods that melt in the mouth, soften the puffs with water first (NIAID’s recipe uses 4 to 6 teaspoons of water for 21 puffs).

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 peanut 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 2% of US children have a peanut allergy, the most common food allergy in kids. (FARE)
Outgrowing it: It lasts in about 3 in 4 children who have it, while most children outgrow a milk or egg allergy. (ASCIA)
Cross-reacts with: Peanut is a bean, not a tree nut, and a peanut allergy does not by itself mean a tree nut allergy. But about 40% of children with a tree nut allergy also react to peanut, so ask your allergist which nuts to test. (FARE)

Frequently asked questions

When can babies have peanut butter?

Most babies can try peanut in a safe, thinned form around 6 months, once they are developmentally ready for solids. Babies with severe eczema or an egg allergy should be evaluated by a pediatrician first, as guidelines may recommend earlier, supervised introduction.

How much peanut should I give a baby?

Start small: a tiny taste of thinned smooth peanut butter. Then, if tolerated, work up to a regular amount a few times a week. Keeping peanut in the diet regularly is part of current guidance. Ask your pediatrician about amounts.

What are signs of a peanut allergy in babies?

Watch for hives or welts (not just a mild rash around the mouth), swelling of the lips, face, or eyes, or vomiting, usually within minutes to two hours. If you see any, stop the peanut and get medical advice right away. Call emergency services for swelling of the tongue or throat, trouble breathing, wheezing, or a cough that keeps going. Also call 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.

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.

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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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