Most healthy, full-term newborns do well on a standard cow’s milk-based formula. It’s the most widely available type, designed to closely mirror breast milk in its balance of protein, fat, and carbohydrates. But “standard” is just one category among several, and the right choice depends on your baby’s digestion, any allergies in the family, and specific medical conditions. Here’s what separates each type and when it matters.
Standard Cow’s Milk Formula
This is the default recommendation for most newborns. Manufacturers adjust the protein in cow’s milk to approximate the ratio found in human breast milk, typically around 40% casein to 60% whey protein. The primary sugar is lactose, the same carbohydrate in breast milk, though some brands also include maltodextrin. Fat comes from a blend of vegetable oils, sometimes with added milk fat.
If your pediatrician hasn’t flagged a specific concern like a milk protein allergy or digestive issue, a standard cow’s milk formula is almost certainly where you’ll start. Store brands and name brands sold in the U.S. must meet the same federal nutrient requirements, so the nutritional content is effectively the same regardless of price.
What the FDA Requires in Every Formula
Every infant formula sold in the United States must meet minimum (and in some cases maximum) levels for over 30 nutrients per 100 kilocalories. That includes 1.8 to 4.5 grams of protein, 3.3 to 6.0 grams of fat (providing 30% to 54% of calories), at least 250 IU of vitamin A, at least 40 IU of vitamin D, and at least 0.15 milligrams of iron, among many others. Sodium, potassium, chloride, and iodine all have upper limits to protect a newborn’s developing kidneys and heart.
This means no formula on U.S. shelves can legally skip a critical nutrient. The differences between brands come down to optional ingredients and protein processing, not whether basic nutrition is covered.
Formulas With DHA and ARA
Many U.S. formulas add two fatty acids, DHA and ARA, that are naturally present in breast milk. These support brain and eye development. In clinical studies, infants who received formula with DHA and ARA had measurably sharper visual acuity than those who didn’t. Follow-up testing showed benefits in vocabulary and verbal IQ at ages five and six, along with better performance on tasks involving rule-learning and impulse control between ages three and five.
DHA and ARA also play a role in reducing inflammation and may lower allergy risk in early childhood. In the European Union, DHA is a required ingredient in all infant formulas. In the U.S., it’s optional, so you’ll want to check the label if this matters to you. Most major U.S. brands include it, but not all do.
Partially Hydrolyzed Formula
In a partially hydrolyzed formula, the milk proteins are broken into smaller fragments. This makes digestion easier and can be a good middle-ground option for babies who seem fussy or gassy on standard formula but don’t have a diagnosed milk allergy. These formulas are sometimes labeled “gentle” or “comfort.”
Research shows partially hydrolyzed formula reduced the risk of eczema by about 29% and the risk of wheezing by 50% in children under two, compared to standard cow’s milk formula. That protective effect tends to fade after age two as the immune system matures. If you have a family history of eczema or allergies, this type is worth discussing with your pediatrician as a preventive step.
Extensively Hydrolyzed Formula
Extensively hydrolyzed formulas break proteins down even further, into fragments so small that the immune system is unlikely to recognize them as cow’s milk protein. Over 95% of the protein pieces weigh less than 3,000 daltons, compared to the 3,000 to 10,000 dalton range in partially hydrolyzed versions. This is the primary formula recommended for infants with a confirmed cow’s milk protein allergy.
In children under two, extensively hydrolyzed formula reduced the risk of cow’s milk allergy by 38% compared to standard formula. It also showed a long-term benefit against eczema after age two, likely because ongoing exposure to tiny protein fragments helps train the immune system toward tolerance. These formulas taste more bitter than standard options, so some babies need a transition period. They also cost significantly more.
Amino Acid Formula
For the small number of infants who still react to extensively hydrolyzed formula, amino acid-based formulas exist. These contain no intact protein at all, only individual amino acids. They’re used for severe cow’s milk allergy or conditions like protein-induced enterocolitis, where the gut lining becomes inflamed from milk protein exposure.
Soy-Based Formula
Soy formula replaces cow’s milk protein with soy protein and swaps lactose for a different sugar, typically sucrose. According to the American Academy of Pediatrics, the clear medical reasons to choose soy formula are narrow: galactosemia (a rare condition where the body can’t process the sugar in milk), hereditary lactase deficiency (extremely rare in newborns), or a family preference for a vegetarian diet.
Soy formula is not a reliable alternative for babies with cow’s milk protein allergy. Infants with documented cow’s milk protein-related gut inflammation are frequently just as sensitive to soy protein and should use a hydrolyzed or amino acid formula instead. Soy formula is also specifically contraindicated for babies with certain enzyme deficiencies that prevent them from digesting sucrose or fructose.
Anti-Reflux (Thickened) Formula
If your newborn spits up frequently and isn’t gaining weight well, your pediatrician may suggest an anti-reflux formula. These contain a thickening agent, usually rice starch or carob bean gum, that increases the formula’s viscosity so it’s more likely to stay down.
Clinical evidence confirms that thickened formulas reduce both the frequency and severity of regurgitation and can improve weight gain. They’re intended for formula-fed infants with persistent spit-up that hasn’t improved with smaller, more frequent feedings. They’re not necessary for the occasional spit-up that most newborns experience, which typically resolves on its own.
Goat’s Milk Formula
Goat’s milk formula is a newer option in the U.S. market. Some goat milk formulas have completed the required FDA premarket review, but others have been sold without it. In 2024, the FDA flagged an imported goat milk formula for dangerously high potassium and chloride levels (which can strain a newborn’s kidneys and heart) and low vitamin A (which can impair vision over time). If you’re interested in goat’s milk formula, verify that the specific brand has gone through FDA review. The protein in goat’s milk is structurally similar to cow’s milk, so it’s generally not appropriate for babies with a confirmed cow’s milk protein allergy.
Ready-to-Feed vs. Powdered vs. Concentrate
Formula comes in three physical forms, and the distinction matters most in the first two months of life.
- Ready-to-feed liquid is sterile straight from the container. You pour it into a bottle and serve. No mixing, no water concerns. This is the safest option for newborns under two months, premature babies, and infants with weakened immune systems, because it eliminates the small risk of bacterial contamination found in powdered products.
- Powdered formula is the most affordable and most popular. However, it is not sterile. It can occasionally harbor harmful bacteria like Cronobacter. For babies under two months, health authorities recommend mixing powdered formula with water that has been boiled and then cooled to about 70°C (158°F), which takes roughly 30 minutes after boiling. Water at this temperature kills potential bacteria in the powder itself.
- Liquid concentrate requires mixing with equal parts water. It’s a middle option in terms of cost and convenience, but still requires clean water.
Ready-to-feed is the most expensive per ounce, but many parents use it for the first few weeks and then transition to powder once their baby’s immune system is a bit more developed.
U.S. vs. European Formula
Some parents seek out European brands, believing them to be higher quality. There are real regulatory differences. The EU requires DHA in all infant formulas, while the U.S. does not. European formulas also typically contain less iron than their American counterparts. U.S. regulations require that any formula with at least 1 mg of iron per liter be labeled “iron-fortified,” while formulas with less iron must be labeled “low iron.” No similar labeling rule exists in Europe.
Importing European formula comes with practical risks. Shipping conditions may not maintain proper storage temperatures, labels may not be in English, and the product hasn’t gone through the FDA’s safety review process. The nutritional profiles are broadly similar, but the safeguards around distribution and labeling are not.