What the Evidence Shows

Large studies found that babies at high risk for peanut allergy who ate peanut regularly from 4 to 11 months were far less likely to develop the allergy by age 5. The Centers for Disease Control and Prevention (CDC) and the AAP both support offering common allergens as part of normal infant and toddler nutrition once solids begin. The World Health Organization (WHO) also emphasizes continued breastfeeding alongside the gradual addition of complementary foods from about 6 months.

Who Should Start Early

Most babies can begin around 6 months. Babies with severe eczema or an existing egg allergy face higher risk and may benefit from starting peanut between 4 and 6 months, sometimes after allergy testing. If your infant falls into this group, review a plan with your pediatrician first. Our introducing solids at 6 months guide explains the readiness signs in detail.

Start small. A serving of 1 to 2 teaspoons of a new allergen is plenty for a first taste. There is no benefit to large amounts, and smaller portions make it easier to spot a reaction. Build up to about 2 tablespoons over several exposures if your baby tolerates the food well.

By now most of the top-9 should be familiar foods. Continue variety and texture progression toward finger foods. Remember that cow’s milk as a drink and honey should wait until after 12 months. See our foods to avoid before 12 months list for the full rundown.

Ground tree nuts, soft tofu, flaked fish, minced shellfish, and thinned tahini all work well. Pair new allergens with a food your baby already tolerates, and keep portions to about 1–2 teaspoons on first tries. Our iron-rich first foods article shows easy combinations.

When to Call Your Pediatrician

Call your pediatrician the same day for mild symptoms like a small rash, a few hives, or tummy upset after a new food. Call emergency services right away for swelling of the lips or face, repeated vomiting, wheezing, or any difficulty breathing. If your baby has severe eczema or a known allergy, review your introduction plan with your pediatrician before starting the top-9 allergens at home.

When should I start my baby’s first foods allergen introduction?

Most babies are ready around 6 months, once they sit with support and show food interest. The AAP recommends introducing common allergens early rather than delaying them. If your baby has severe eczema or an existing allergy, start peanut and egg between 4 and 6 months. Begin with one allergen, offer a small amount, and repeat it weekly.

What are the top-9 food allergens I should introduce?

The top-9 allergens cause about 90% of childhood food reactions: milk, egg, peanut, tree nuts, soy, wheat, fish, shellfish, and sesame. You do not need to introduce all nine at once. Offer them gradually, one at a time, over several weeks. Keep servings small—roughly 1 to 2 teaspoons—and watch your baby for about 15 minutes after each new food.

How do I serve peanut safely to my baby?

Never give a baby whole peanuts or peanut butter from a spoon. Thin 1 to 2 teaspoons of smooth peanut butter with breast milk, formula, or water to a runny paste. Offer it at the start of a calm meal. Repeat peanut 2 to 3 times weekly, since regular exposure builds tolerance better than one taste.

What are the signs of a food allergy reaction?

Mild signs include a few hives, a rash around the mouth, or mild tummy upset. More serious signs are swelling of the lips or face, repeated vomiting, wheezing, or trouble breathing. Reactions usually appear within minutes to 2 hours of eating. If you see breathing trouble, call emergency services right away. For milder symptoms, contact your pediatrician the same day.

Can I introduce allergens if my baby has eczema?

Yes, but timing matters. Babies with mild eczema can follow the usual plan starting near 6 months. Those with severe eczema or an egg allergy face higher risk and may benefit from early peanut introduction between 4 and 6 months, sometimes with allergy testing first. Always review your baby’s plan with your pediatrician before offering the top-9 allergens at home.