What Is A2 Baby Formula?

A2 baby formula is made with cow’s milk that contains A2 beta-casein but no A1 beta-casein. If you are considering it because your baby seems uncomfortable after feeds, you may wonder whether that protein difference matters. 

Early infant studies report some differences in digestive comfort, but they do not show that A2 formula will help every baby. A2 formula is also not suitable as a treatment for cow’s milk protein allergy.

What Is A2 Baby Formula?

A2 refers to beta-casein, one of the proteins in cow’s milk. A1 and A2 are variants of that protein. Conventional cow’s milk commonly contains both, while milk selected for A2 formula does not contain A1 beta-casein.

The A2 label describes a milk protein, not a milk sugar. An A2 infant formula may still contain lactose, so “A2” does not mean “lactose-free.” Check the complete label to see what a particular formula contains.

How Is A2 Formula Different From Regular Formula?

A2 describes the beta-casein profile of the milk used in a formula. It does not describe the formula’s complete composition.

Two finished formulas may also differ in their fats, carbohydrates, and other ingredients. Compare their complete ingredient and nutrition labels rather than assuming an A2 formula is nutritionally superior.

Is A2 Formula Easier to Digest?

Current infant studies do not establish that A2 formula is easier to digest for most babies. They report some differences in digestive comfort, but the studies have limitations, and an individual baby may respond differently.

What Do Infant Studies Show?

In a 2025 randomized trial, healthy, mixed-fed infants aged 3 to 4 months received either formula made with milk free of A1 beta-casein or conventional cow’s milk formula. At weeks two and four, the A2 group had lower parent-reported scores for symptoms including spitting up, crying, and fussiness. 

The trial continued through week eight, but the differences cited here were measured at weeks two and four. Parents knew which formula their babies received, and mixed feeding may have influenced the results. An A2 milk company funded the research. 

A 2024 randomized trial reported softer stools and some measures of improved comfort in infants given an A2 formula. However, that formula also contained more sn-2 palmitate and added casein phosphopeptides than the comparison formula. The researchers could not isolate the effect of A2 beta-casein from those other differences. The study received industry funding.

Together, these trials make A2 formula a reasonable subject for further study. They do not prove that switching to A2 will relieve gas, spit-up, or fussiness in your baby. If digestive discomfort persists, speak with your pediatrician before changing formulas to address it.

How Does A2 Compare With Other Formula Types?

A2, hypoallergenic, and lactose-free formulas describe different changes to a formula.

Formula type	What changes	What parents need to know
A2 cow's milk formula	Its milk contains A2 beta-casein without A1 beta-casein.	It still contains cow's milk proteins and is not a milk-allergy treatment.
Standard cow's milk formula	Its milk commonly contains A1 and A2 beta-casein.	It is a routine option for many infants.
Extensively hydrolyzed formula	Milk proteins are broken into much smaller pieces.	A pediatrician may recommend it for cow's milk protein allergy.
Amino acid formula	It uses individual amino acids instead of intact milk proteins.	A pediatrician may recommend it for certain infants with milk allergy.
Lactose-free formula	Lactose is replaced with another carbohydrate.	It addresses a different issue from the A1/A2 protein distinction.

If you suspect a milk allergy or are considering lactose-free formula for ongoing symptoms, ask your pediatrician which type is appropriate. The American Academy of Pediatrics notes that significant lactose intolerance is rare in infants.

For a broader look at standard and specialized options, see our guide to choosing baby formula.

Should You Consider A2 Formula for Your Baby?

A2 formula may be one option if you are comparing routine cow’s milk-based infant formulas. The A2 label alone cannot tell you whether your baby will tolerate it better than another product.

If your baby is feeding comfortably and growing well, the current evidence does not establish a reason to switch solely for the A2 protein. When comparing formulas, look at the complete label, age suitability, availability, and cost. Infant formulas legally marketed in the United States must meet applicable FDA requirements for nutrition, safety, and labeling.

If symptoms are driving your search, avoid assuming A1 beta-casein is the cause. Contact your pediatrician about persistent discomfort, especially when it occurs with poor weight gain, blood in the stool, or repeated vomiting. Your pediatrician can assess the symptoms and advise whether a formula change is appropriate.

For help recognizing symptoms that warrant a call, read when to contact your pediatrician about formula-feeding symptoms.

Frequently Asked Questions

Can newborns drink A2 baby formula?

An A2 product labeled as infant formula for birth to 12 months may be an option for a newborn. Follow its preparation directions exactly. Ordinary cow’s milk and toddler drinks should not replace infant formula before 12 months. 

Is A2 formula the same as organic formula?

No. A2 refers to a variant of milk protein. USDA organic labeling refers to how a product is produced under organic standards. A formula may be A2, organic, both, or neither.

Is A2 formula worth the extra cost?

A higher price does not mean A2 formula will improve your baby’s digestion. Consider the complete formula, consistent availability, and your family’s circumstances. If symptoms are driving your choice, ask your pediatrician what type of formula is appropriate.

Is A2 formula the same as goat milk formula?

No. A2 describes a beta-casein variant, while goat milk identifies the milk source. Neither label makes a formula suitable for a cow’s milk protein allergy. The American Academy of Pediatrics advises against goat milk products for infants with cow’s milk allergy.

This article is for general informational and educational purposes only and is not intended as medical advice. Breastfeeding is recommended as the best source of nutrition for most infants. Always consult your pediatrician about your baby’s feeding, formula choice, and any health concerns, especially if your baby was born prematurely, has allergies, or has any underlying health condition.

References

• Li et al., Effect of Infant Formula Made With Milk Free of A1-Type β-Casein on Growth and Comfort: A Randomized Controlled Trial - https://pmc.ncbi.nlm.nih.gov/articles/PMC12264312/ PMC
• Sheng et al., An A2 β-Casein Infant Formula With High sn-2 Palmitate and Casein Phosphopeptides Supports Adequate Growth, Improved Stool Consistency, and Bone Strength in Healthy, Term Chinese Infants: A Randomized, Double-Blind, Controlled Clinical Trial - https://www.frontiersin.org/journals/nutrition/articles/10.3389/fnut.2024.1442584/full PMC
• American Academy of Pediatrics, Choosing a Baby Formula - https://www.healthychildren.org/English/ages-stages/baby/formula-feeding/Pages/Choosing-an-Infant-Formula.aspx HealthyChildren.org
• U.S. Food and Drug Administration, Infant Formula Homepage - https://www.fda.gov/food/resources-you-food/infant-formula-homepage FDA
• Centers for Disease Control and Prevention, Cow’s Milk and Milk Alternatives - https://www.cdc.gov/infant-toddler-nutrition/foods-and-drinks/cows-milk-and-milk-alternatives.html CDC
• U.S. Department of Agriculture, USDA Certified Organic: Understanding the Basics - https://www.ams.usda.gov/services/organic-certification/organic-basics