Peanut introduction at 4-6 months

Track the introduction date and any reactions in the First Foods Tracker.

The LEAP study, in plain English

In 2015, the Learning Early About Peanut allergy study (LEAP) published results that changed pediatric allergy practice. They followed 640 high-risk babies (severe eczema and/or egg allergy) from infancy. Half were given peanut foods starting at 4 to 11 months. Half had peanut completely avoided until age 5.

At age 5, the avoidance group had a 17% peanut allergy rate. The early introduction group had a 3% rate. An 86% reduction in peanut allergy from early exposure.

That's a massive effect size. NIAID rewrote its guidelines in 2017 to recommend early peanut introduction. The AAP followed. Modern pediatric advice is to actively introduce peanut early, not delay.

Timing: 4 to 11 months

The window is broader than people realize. Current guidance:

• High-risk babies (severe eczema, egg allergy): Introduce at 4 to 6 months, ideally with pediatrician guidance or in-office.
• Moderate-risk babies (mild-to-moderate eczema): Introduce at 6 months at home, with your standard allergen-introduction precautions.
• Low-risk babies (no eczema, no family allergy history): Introduce at 6 months at home, alongside other solid foods.

The earlier extreme of the window is for high-risk babies because the protective effect is strongest there. For most babies, 6 months is the practical sweet spot — they're ready for solids, the protective window is still open, and you've already done a few other foods.

Get pediatric input first if your baby has these

• Severe eczema (moderate to severe, persistent, requiring prescription treatment).
• Diagnosed egg allergy.
• Sibling with a peanut allergy or other severe allergy.

Your pediatrician may want allergy testing before peanut introduction, or may want you to do it in their office. Both are reasonable. Don't bypass this step for high-risk babies.

How to actually feed peanut

Whole peanuts and globs of straight peanut butter are choking hazards. The two safe formats:

Option 1: Peanut puffs (Bamba, Mission MightyMe)

Peanut-based puffs (the snack aisle staple) dissolve in baby's mouth. They're the format used in many follow-up early-introduction studies. Easy to handle. Easy to portion. The LEAP study itself used Bamba puffs.

Offer 2 to 3 puffs softened in a little water or breast milk. Make sure they dissolve before next bite.

Option 2: Smooth peanut butter, thinned

Take 1/2 to 1 teaspoon smooth (not crunchy) peanut butter. Add 2 to 3 teaspoons of warm water, breast milk, or formula. Stir until smooth and runny. You can also mix it into oatmeal, applesauce, or yogurt.

Do NOT give straight peanut butter from a spoon. The sticky thick consistency is a serious choking risk.

The introduction procedure

1. Pick a healthy morning at home. Not sick, not vaccine day, not teething hard. Morning gives you daylight to monitor.
2. Have your tools. Phone with pediatrician's number, infant antihistamine if pediatrician has recommended one, and your address printed for an emergency.
3. Offer a tiny taste first. About an eighth of a teaspoon of prepared peanut. Rub a small amount onto the lip first if you want extra caution.
4. Wait 10 minutes. Watch for any change — redness, swelling, hives.
5. If no reaction, offer the full portion. About 2 teaspoons of prepared thinned peanut butter, or 3 to 4 peanut puffs over the course of the meal.
6. Watch for 2 hours. Most IgE-mediated reactions appear in this window. Keep baby in your field of view.
7. No other new foods that day. If a reaction happens later, you need to know what caused it.

Reaction recognition

Mild (call pediatrician, observe)

• A few hives near the mouth or face that don't spread.
• Slight lip swelling that doesn't worsen.
• Mild redness or rash that stays localized.
• One vomit without other symptoms.

Severe (call 911)

• Hives spreading across the body.
• Swelling of lips, tongue, or face that's progressing.
• Difficulty breathing, wheezing, drooling, coughing repeatedly.
• Vomiting repeatedly.
• Pale, floppy, or unresponsive baby.
• High-pitched breathing sound.

Don't wait to see if it gets better. Anaphylaxis can progress in minutes. Call 911 or get to the ER.

The "keep going" part

Introducing peanut once isn't enough. To maintain the protective effect, peanut should stay in baby's diet — about 2 grams of peanut protein, 3 times per week, through age 5 at minimum. That's roughly 2 teaspoons of peanut butter or 6 to 7 Bamba-style puffs per serving, 3 days a week.

Practical maintenance ideas:

• Thinned peanut butter swirled into oatmeal or yogurt.
• Smooth peanut butter spread thin on toast strips or banana.
• Peanut puffs as a snack.
• Peanut butter sauce on noodles (toddler-age) — Thai-style without spice.
• Peanut butter and banana sandwiches.

If you stop offering peanut for many months, the protective tolerance can fade in some kids. The LEAP-On follow-up study showed 12 months of avoidance after early intro generally maintained protection, but sustained exposure is the safer bet.

Common questions

What if my baby refuses peanut puffs or thinned PB?

Mix it into something they already eat. Oatmeal is the most common vehicle. A teaspoon of smooth PB stirred into warm oatmeal disappears. Yogurt works too.

Does the brand of peanut matter?

For natural peanut butter, the only ingredients should be peanuts (and maybe salt — but skip salted varieties for babies under 12 months when possible). Avoid honey-roasted or anything sweetened. Bamba is the studied brand for puffs but other unsweetened, peanut-based puffs work the same.

Can I give peanut at daycare?

Many daycares restrict peanut to protect allergic kids. Introduce at home first. Maintain at home or after pickup. Don't try to introduce a new allergen at daycare.

What about other tree nuts?

Tree nut (almond, cashew, walnut) is a separate allergen category. Introduce each tree nut separately, using thinned nut butter or finely ground varieties. Peanut tolerance doesn't always predict tree nut tolerance.

When to call your pediatrician

• Before introducing if baby has severe eczema, egg allergy, or family history.
• After any reaction — even mild.
• If baby refuses peanut at every attempt and you can't get any in.
• If maintenance feels overwhelming and you want a check on the schedule.
• Before age 5, if you want to discuss whether continued maintenance is still recommended.

Peanut introduction is the single most studied early-allergen exposure. The data on early introduction is overwhelming. The bigger risk to your baby is delaying — not introducing on time at home with a clear plan.