How to choose a formula: ignore most of the label

You're standing in the supermarket aisle staring at forty-odd tins of formula. Some promise "closer to breast milk". One has a gold star on it. Another costs twice as much and features a very serene-looking infant. Your baby is at home, hungry, and you'd quite like to just pick something and leave.

Here's the short version: for a healthy newborn, any Stage 1 (First Infant Formula) will do. The longer version explains why — and what the other tins are actually for.

What the label stages mean

UK infant formulas are regulated by the Infant Formula and Follow-on Formula Regulations 2007, which set minimum and maximum levels for every nutrient. This means every Stage 1 product on a UK shelf — own-brand or premium — meets the same legal nutritional floor. The difference between a £7 tin and a £15 tin is largely marketing.¹

The stages break down like this:

There is no clinical evidence that following the stage numbers improves outcomes. The NHS is direct about this: follow-on formula is not necessary, and you can continue using first infant formula for the whole of the first year.¹ Stage 3 toddler milks are not recommended by the NHS at all — they are higher in sugar and lower in iron than Stage 1.

Standard formula types

All standard formulas are cow's milk-based. They differ in the whey-to-casein ratio:

• Whey-dominant (Stage 1) — the protein profile is closer to breast milk. Suitable from birth.
• Casein-dominant ("hungry baby" formula) — marketed for babies who seem unsatisfied. The evidence that it keeps babies fuller for longer is weak. The NHS does not recommend it as a first choice. If your baby seems hungry, check volumes and feeding cues before switching formula.¹

Specialist formulas: only with medical advice

These are not off-the-shelf decisions:

Partially hydrolysed (HA / "comfort") formula — the proteins are partially broken down. Sometimes marketed for colic or wind. The evidence for symptom relief is poor. This formula is not suitable for treating confirmed cow's milk protein allergy (CMPA) — it is not hydrolysed enough.¹

Extensively hydrolysed formula (eHF) — proteins are broken down into small fragments. Used as first-line treatment for CMPA. Available on prescription. Do not switch to this without a GP or dietitian's guidance; CMPA diagnosis involves ruling out other causes.

Amino acid formula (AAF) — for severe CMPA or when eHF is not tolerated. Prescribed only.

Lactose-free formula — for temporary lactose intolerance following gastroenteritis, or in rare cases of congenital lactase deficiency. Not appropriate for CMPA (it still contains cow's milk proteins). Not a long-term first choice.

Soy formula — not recommended as a first choice. Around 40–60% of babies with CMPA also react to soy protein. Soy contains phytoestrogens; the long-term effects in infants are uncertain.¹ Available without prescription but should only be used after medical advice.

What to ignore on the label

"Closer to breast milk" — every formula manufacturer makes some version of this claim. Breast milk changes composition feed to feed and cannot be replicated. The claim is legal but not clinically meaningful.

Added DHA, ARA, prebiotics, probiotics, HMOs — some of these are the subject of ongoing research. None have been shown to produce outcomes different enough to justify a price premium in healthy, term babies. SACN reviewed the evidence on infant feeding and found no consistent benefit from these additions over the regulated baseline.²

Stage numbers beyond 1 — see the table above.

"Anti-reflux" or "AR" formula — thickened to reduce spitting up. Occasionally useful for significant reflux, but the evidence is mixed and thickened formula can affect how other things (like medicines) are absorbed. Speak to a GP or health visitor first.

How to actually choose

For a healthy, term baby with no suspected allergies or intolerances:

• Pick any Stage 1 (First Infant Formula) that is convenient and within your budget.
• Own-brand supermarket formulas meet exactly the same regulatory standards as premium brands.
• Stick with it unless there is a clinical reason to change — formula-switching without cause is common and usually doesn't help.
• If you move to a different brand of Stage 1, no gradual transition is needed; the nutritional profile is comparable.

When to call your pediatrician

Speak to a GP or health visitor if your baby has any of the following, rather than switching formula independently:

• Blood or mucus in stools
• Persistent vomiting beyond normal positing
• Significant eczema or skin rashes appearing after formula introduction
• Swelling, hives, or any sign of an acute allergic reaction (call 999 / go to A&E)
• Poor weight gain or failure to return to birth weight by two weeks
• Chronic diarrhoea lasting more than a week

Routine query about formula brands or stages can wait for a scheduled health visitor appointment.

Tracking tip

Logging which formula your baby is on in PooPeeMilk makes it easier to spot patterns if you ever do need to investigate a reaction — you'll have a clear record of when any formula change happened and what followed.

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Also in this cluster: How to prepare formula safely · How much formula by age · Formula intolerance vs CMPA

Sources

• NHS. Types of infant formula. https://www.nhs.uk/conditions/baby/breastfeeding-and-bottle-feeding/bottle-feeding/types-of-infant-formula/
• Scientific Advisory Committee on Nutrition (SACN). Feeding in the First Year of Life. 2018. https://www.gov.uk/government/publications/feeding-in-the-first-year-of-life-sacn-report