How to introduce peanut to your baby

Why peanut early

For years, parents were told to keep peanut away from babies. In 2000, the AAP even advised waiting until age 3 for babies at high risk. That didn’t prevent peanut allergy, and the advice was dropped in 2008.

Then came the LEAP trial. Researchers in the UK followed 640 babies aged 4 to 11 months who had severe eczema, egg allergy, or both. Half ate peanut regularly, at least 6 g of peanut protein a week spread over three or more meals, until age 5. The other half avoided it. Among the babies who had a negative skin test at the start, 13.7% of the avoidance group had peanut allergy at age 5, compared with 1.9% of the group that ate peanut.

A follow-up study, LEAP-On, asked the children from both groups to avoid peanut for a year after their fifth birthday. The children who had eaten peanut since infancy stayed protected: a year without peanut didn’t significantly raise their rate of peanut allergy. At age 6, 4.8% of them had peanut allergy, compared with 18.6% of those who had avoided it. (These figures include the babies who had a positive skin test at the start, so they’re higher than the figures above.)

Based on LEAP, US guidelines from the National Institute of Allergy and Infectious Diseases (NIAID) recommend peanut in infancy for babies at every level of risk: as early as 4 to 6 months for the highest-risk babies, around 6 months for babies with mild to moderate eczema, and along with other solid foods for everyone else. A 2021 consensus from US and Canadian allergy societies goes further: introduce peanut and egg around 6 months, but not before 4 months. The NHS says delaying peanut and hen’s eggs beyond 6 to 12 months may increase the risk of allergy to them.

Talk to your doctor first if…

• your baby has severe eczema: eczema that keeps coming back or never fully clears and needs prescription creams often (AAP)
• your baby has an egg allergy, or has had an immediate allergic reaction to any food

These babies have the highest chance of peanut allergy, and early peanut matters most for them, often from around 4 to 6 months. The AAP suggests raising it early, at the 2- or 4-month checkup. NIAID suggests an allergy test for these babies, and a first taste in the doctor’s office if the result calls for it. The 2021 consensus says testing first isn’t required, though some families prefer it. Either way, don’t give the first peanut at home until your doctor has told you how. Testing can take time, so ask soon.

If your baby has mild to moderate eczema and no food allergy, NIAID says peanut can usually be introduced at home around 6 months, and testing isn’t needed. The AAP says to still talk with your pediatrician about your baby’s situation. If your baby has no eczema and no food allergy, peanut can go in with other first foods, following your family’s preferences.

Before the first taste

• Start solids first. NIAID and the AAP both say to give a few other solid foods before peanut, to show your baby is ready. The AAP suggests foods like infant cereal or puréed fruit.
• Pick a good day. Choose a day your baby is well, at home, when you can watch them for a couple of hours afterward. NIAID’s home feeding instructions say to give the first peanut at home, not at day care or a restaurant.
• Keep it separate. Offer peanut on a day you’re not trying any other new food, so you can tell what caused any reaction.

Safe forms of peanut

Peanut is safe for babies only in smooth, thinned or finely ground forms.

• Thinned smooth peanut butter. Stir about 2 teaspoons of smooth peanut butter with 2 to 3 teaspoons of hot water until it’s runny and well blended, then let it cool. NIAID’s instructions use hot water this way. You can also thin it with breast milk or formula, or stir it into infant cereal, puréed fruit or yogurt your baby has already had (AAP). See peanut butter for more ways to serve it.
• Peanut powder or peanut flour. NIAID suggests about 2 teaspoons of peanut powder or flour stirred into about 2 tablespoons of a puréed fruit or vegetable your baby already eats.
• Finely ground peanuts. The NHS and ASCIA (the Australian allergy society) also list peanuts finely ground and mixed into food.

Never give these to a baby or toddler:

• whole or chopped peanuts. The AAP says to wait until at least age 4; the NHS says no whole nuts under 5
• spoonfuls or chunks of peanut butter, which the CDC lists as a choking hazard
• chunky peanut butter (AAP)

Start with a small amount, using one of these two plans:

• NIAID’s home steps: make up the 2-teaspoon serving, offer a small taste on the tip of a spoon, and wait 10 minutes. If there’s no reaction, give the rest at your baby’s usual pace. The peanut butter page follows these steps.
• ASCIA’s build-up: start with about a quarter of a teaspoon mixed into food, and if there’s no reaction, build up over the next few times you offer it.

Either way, stay with your baby and stop if you see any sign of a reaction.

How often to keep offering peanut

Getting peanut started is only the first step. LEAP’s protection came from regular eating over years, not a single taste.

• For babies at high risk (severe eczema or egg allergy) whose doctor has cleared peanut, NIAID recommends about 6 to 7 g of peanut protein a week, over three or more feedings. About 2 teaspoons of peanut butter has about 2 g of peanut protein, so that’s roughly 2 teaspoons of peanut butter three times a week.
• For other babies, the 2021 consensus says there’s no proven exact dose. It suggests about 1 to 2 teaspoons of peanut butter at least once a week, and more if your baby enjoys it. ASCIA also says at least once a week. The AAP gives about 2 teaspoons of peanut butter as a regular portion.
• Don’t stop it once it’s in the diet, unless there are signs of an allergic reaction (2021 consensus).

For ideas on fitting peanut into a busy week along with egg, sesame and the rest, see keeping allergens in the diet.

Signs of an allergic reaction

Reactions usually start within minutes of eating, but can take up to 2 hours (NHS).

Mild to moderate: hives or a red, itchy rash, especially around the mouth; mild puffiness of the face or around the eyes; vomiting once, tummy pain or diarrhea; sneezing or a runny nose. If it’s only one of these, stop offering peanut, stay with your baby and watch them closely for the next couple of hours, and call your pediatrician before you try it again. If signs show up in more than one part of the body at once, treat it as severe (below).

Severe (anaphylaxis): trouble breathing, wheezing, or a cough that won’t stop; swelling of the tongue or throat, lips or mouth that suddenly swell, a hoarse cry, drooling or trouble swallowing; turning pale or floppy, or very sleepy or unresponsive; or signs in more than one part of the body at once, such as hives with repeated vomiting.

If your baby has an epinephrine (adrenaline) auto-injector, use it right away, then call for an ambulance. Call 911.Call 999.Call your local emergency number (such as 112 in Europe or 000 in Australia). If you don’t have an auto-injector, call straight away. Keep your baby lying down, never standing or walking (on their side if they’re vomiting, head and shoulders a little raised if breathing is hard), and go to hospital even if they seem better. See signs of anaphylaxis.

Where US and UK advice differs

• Who should check with a doctor first. US guidance singles out babies with severe eczema or egg allergy. The NHS asks you to talk to your GP or health visitor first if your baby has any eczema or a diagnosed food allergy, or if there’s a family history of food allergies, eczema, asthma or hay fever.
• How to serve peanut butter. The AAP suggests thinning it into cereal, purée or yogurt, or dissolving it in breast milk or formula. The NHS suggests spreading it onto a food such as toast (we suggest spreading it thinly), or giving crushed or ground nuts mixed into food. Both say never give nut butter on its own.
• Whole nuts. The AAP says to avoid whole peanuts until at least 4 years. The NHS, and the safety notes in the NIAID guidelines, say no whole nuts under 5.

For the other common allergens, see how to introduce allergens and the safe first form of each one. If your baby has eczema, see eczema and starting solids.