There are roughly 30 formulas on the US market, and the marketing for all of them works hard to make each formula sound categorically different from the others. Most of those differences are smaller than the marketing suggests. A few are real and matter.
This is a brand-agnostic guide to actually picking one. What to look at, what to ignore, and what to do if your first choice isn't working.
The bottom line, up front
Every formula sold in the US is required to meet FDA nutritional standards for infant formula. The standards specify minimum amounts of about 30 nutrients. Any FDA-compliant formula will adequately feed your baby.
What varies between formulas:
- The type of milk protein (cow's milk, goat, soy, hydrolyzed)
- The type of carbohydrate (lactose, corn syrup, sucrose)
- Whether DHA, ARA, prebiotics, probiotics, or HMOs are added (most modern formulas have at least DHA and ARA)
- The presence or absence of organic ingredients
- Country of manufacture and which standards apply (FDA in the US; EU regulations elsewhere)
The "best" formula for your baby is the one they tolerate well, that fits your budget, and that's reliably available. That's it.
If you log feeds and any reactions in Tottli during the first two weeks of a new formula, the answer to "is this working?" becomes a pattern on the timeline rather than a guess from one bad afternoon.
The four main types
Almost every formula on the shelf is one of these.
1. Standard (intact) cow's milk-based formula
This is what most babies start on. The protein is regular cow's milk protein. Lactose is the primary carbohydrate. DHA, ARA, and other "extras" are typically included.
Examples: Similac Pro-Advance, Enfamil NeuroPro, Kirkland (Costco) ProCare, Up & Up (Target store brand), Parent's Choice (Walmart store brand).
Use when: your baby has no digestive issues and your pediatrician hasn't recommended otherwise.
Cost: $0.95–$1.30/oz prepared, depending on brand.
2. Partially hydrolyzed ("gentle" or "sensitive") formula
Cow's milk protein, but partially broken down into smaller pieces. Often paired with reduced lactose. Marketed for "fussy babies" and gas. The actual evidence that partial hydrolysis significantly reduces fussiness is mixed: some babies improve, others don't change.
Examples: Similac Pro-Sensitive, Enfamil Gentlease, Kirkland Gentle.
Use when: your baby has persistent gas or fussiness on standard formula and your pediatrician suggests trying a gentler option.
Cost: slightly more than standard; ~$1.10–$1.40/oz prepared.
3. Extensively hydrolyzed (hypoallergenic) formula
Cow's milk protein broken down into very small pieces, too small for most cow's milk allergic babies to react to. Used for babies with confirmed cow's milk protein allergy or severe intolerance.
Examples: Nutramigen, Alimentum, Pregestimil.
Use when: your pediatrician diagnoses a milk protein allergy or severe intolerance. These are not for general fussiness.
Cost: significantly more, ~$2.00–$2.50/oz. Often partially or fully covered by insurance with a pediatrician's prescription.
Note: these formulas have a strong, slightly unpleasant smell and taste due to the hydrolysis. Babies who start on them from birth accept them fine; switching to one later can take a few days of resistance.
4. Amino acid-based (elemental) formula
The most broken-down option, with proteins reduced to individual amino acids. Used for babies who can't tolerate even hypoallergenic formula.
Examples: EleCare, Neocate, PurAmino.
Use when: your pediatrician or pediatric GI specialist recommends. Almost always insurance-covered for diagnosed conditions.
Cost: $3.00+/oz; almost always insurance-covered when prescribed.
Other categories worth knowing about
Soy formula (Similac Soy, Enfamil ProSobee): used for babies with galactosemia or for families avoiding cow's milk for religious/dietary reasons. Not generally recommended as a fussiness fix; the AAP doesn't endorse it as a treatment for colic.
Goat milk formula (Kabrita): popular as a "gentle alternative." Some babies tolerate it well. Not a true allergy solution since most babies allergic to cow's milk are also allergic to goat. Pricier.
Toddler formula (12+ months): not necessary. After 12 months most babies transition to whole milk + a varied diet. Toddler formula is largely a marketing category.
What "European formula" actually means
European formulas (HiPP, Holle, Aptamil, Kendamil) get strong word-of-mouth among US parents. Some real differences, some marketing.
Real differences:
- EU regulations require formulas to use lactose as the primary carbohydrate (no corn syrup-based formulas allowed)
- Some EU formulas use a higher percentage of organic ingredients
- A few use whole milk fat sources (Kendamil) rather than a vegetable oil blend
- Slightly different "stages" by age, more granular than US formulas
Mostly marketing:
- "European standards are stricter." Both EU and FDA standards are robust; they emphasize different things.
- "Cleaner ingredient lists." Modern US formulas like Bobbie and ByHeart are equivalent.
- "Better for sensitive babies." No clear evidence.
Real downsides:
- Not FDA-regulated when imported. Quality control is the EU manufacturer's, but importation routes can be questionable.
- Not always covered by WIC or insurance
- More expensive
- Cooking instructions in metric / different scoop sizes
If you want a US formula with EU-style ingredients (lactose-only, no corn syrup, whole milk fat, organic), look at Kendamil Organic, Bobbie, ByHeart, or Earth's Best Organic. These are FDA-regulated and equivalent on most measurable dimensions.
"Generic" and store brands
Store brand formulas (Kirkland Signature, Up & Up, Parent's Choice, Member's Mark) are manufactured by major formula companies (Perrigo Nutritionals primarily) and are required to meet the same FDA standards as the name brands. They are nutritionally equivalent.
The main differences:
- Sometimes slightly different "extras" (e.g., specific probiotic strains)
- Often dramatically cheaper. Store brands are typically 30–50% less than brand-name equivalents.
- Less heavy advertising
If your baby tolerates a name-brand formula, the store-brand equivalent will almost always work just as well, at a much lower cost. The store-brand formulas generally have a "Compare to [name brand]" label so you can match the equivalent line.
For an exclusively formula-fed baby, going with a store brand can save $1,500–$3,000 in the first year alone.
How to actually pick
A simple decision tree:
Has your baby been recommended a specific formula by a pediatrician? → Use it. The recommendations come from a clinical reason.
Is your baby healthy with no digestive issues? → Start with a standard cow's milk formula, name brand or store brand based on budget. Most babies do fine on these.
Has your baby tried standard formula for 5–7 days and seems persistently uncomfortable? → Talk to your pediatrician. They might suggest trying a sensitive/partially hydrolyzed formula, or might rule out other causes (overfeeding, reflux, normal newborn fussiness).
Does your baby have visible signs of allergy (blood in stool, severe eczema, persistent vomiting, hives)? → See your pediatrician. Hypoallergenic formula may be needed. Don't switch on your own without input.
Are you trying to match an "ideal" ingredient list (organic, lactose-only, no corn syrup)? → Bobbie, Kendamil, ByHeart, Earth's Best Organic are FDA-regulated US options that match EU-style ingredient lists.
Are you on WIC or budget-constrained? → Use the formula your WIC office provides, or use a store-brand equivalent. They are nutritionally complete.
The first week on a new formula
When you start a formula or switch to a new one, expect a brief adjustment:
- Stool changes for 3–5 days (different color, frequency, consistency)
- More gas for the first few days, usually settles
- Fussiness for 24–48 hours, usually settles
- One or two unusual feeds as the baby gets used to the taste
Give it at least 5–7 days before deciding it's not working. Switching every 2–3 days through multiple formulas often makes things worse, not better. Every switch causes its own adjustment period.
Real signs the formula isn't working
Genuine intolerance signs (these warrant a pediatrician call, not a self-switch):
- Blood in stool (any amount, any time, on any formula)
- Persistent vomiting (not normal spit-up; forceful and frequent)
- Severe eczema that started or worsened with formula
- Hives, rash, or facial swelling
- Severe diarrhea for more than 24 hours
- No weight gain at the next visit despite adequate intake
- Constant inconsolable crying that's not improving
Mild fussiness, gas, or stool variability is not enough to switch. Most babies on standard formula are fine.
Mixing and storage basics
A few practicals that aren't always explained well:
Powder vs. ready-to-feed (RTF): RTF is sterile, slightly more expensive, and the right choice for under-2-month-olds and immunocompromised babies. Powder is fine for healthy babies after the first 2 months, but is not sterile. The CDC recommends mixing with hot water (158°F / 70°C) and cooling before feeding to be extra cautious for newborns under 2 months, premature babies, and immunocompromised babies.
Concentrate: rarely used now, sits between powder and RTF. Half water, half formula concentrate.
Water: tap water is fine in most US locations if your tap water is generally safe to drink. Bottled water or nursery water is fine but unnecessary. Boiled-and-cooled water is the safest option for newborns under 2 months.
Storage:
- Mixed bottle: use within 1 hour at room temperature, or up to 24 hours refrigerated (some formulas say 24, some 48; check the label)
- Once a baby drinks from a bottle: discard remainder within 1 hour
- Opened powder canister: use within 1 month
- Sealed canister: check expiration date
Don't add cereal, breast milk, or anything else to formula without pediatric advice. Cereal in particular is unsafe for babies under 6 months.
A note on shortages
Following the 2022 formula shortage, supply has stabilized but isn't perfectly stable. A few defenses:
- Don't rely on one specific formula being available; know your baby's "next-best" option
- A 1–2 week buffer at home is reasonable; hoarding worsens shortages
- Generic / store brand availability is usually more stable than premium brands
- For hypoallergenic formulas, get the prescription-required version through a medical supplier
What this comes down to
"Best formula" is a label, not a real category. Pick a formula your baby tolerates, that fits your budget, and that's reliably stocked nearby. Standard cow's milk formula works for most babies. Store brands save thousands. Hypoallergenic formulas exist for genuine medical needs, not marketing-driven "sensitivity" worries.
The formula category is one of the most marketed-at corners of new parenthood. Tune most of it out. Talk to your pediatrician when something genuine seems off. Otherwise, the cheaper, simpler, store-brand option is usually the right answer.