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What’s the formula for formula?


Whilst breastfeeding confers myriad benefits for infants and their mothers, there are many reasons why some infants will require formula, at least at some point in their first 12 months of life. Having a basic understanding of the different products available and the way formula should be prepared and administered is important for all doctors and nurses working with young children. The variety of formulas, bottles and teats available, as well as the complexities of preparation, administration, and storage, confuses the best of us, so here’s my attempt to make it a little clearer.

What’s in formula and which one is best?

Samantha, a new mum, is unable to continue breastfeeding and seeks your advice as to which is the ‘best’ formula to use for baby Charlie. You support her choice, having gently explored her reasons and provided education and counselling where needed. You then do a quick Google search together to see what’s available at Sam’s local pharmacy, and are rapidly as overwhelmed as Samantha is by the vast array of products for sale…

As these products are often an infant’s sole source of nutrition, their formulation must be, and is, tightly regulated. In Australia, this is done under the Australia New Zealand Food Standards Code. The composition is based on breastmilk, but lacks many important components of the latter, including living cells, free amino acids, enzymes, and various other bioactive substances. So it’s not the same thing (by a long stretch), but it’s the only safe alternative we have, and we’re fortunate to have a Plan B when breastmilk isn’t available for whatever reason. 

Most infants will tolerate a cow’s milk-based formula, and despite colourful marketing campaigns, there is at present no evidence that any one product approved for use in Australia is better than any other. There is also no advantage in using a ‘follow-on’ formula for infants age 6-12 months (and ‘toddler’ formulas are almost exclusively unnecessary). The only thing to be aware of is to avoid formulas with higher protein levels, as these have been associated with excessive weight gain. Sticking to a formula with protein levels close to that of breastmilk (1-1.1g/100ml) is ideal. 


Fancy formulas

Samantha is back, having tried 3 different formulas for Charlie. He became constipated on the first, ‘vomited constantly’ with the second, and refused the third. She has no idea what to do now. Charlie is growing well and is happy, although Samantha reports he has a tendency to frequently decorate his clothes (and hers) with his stomach contents.

Everyone around Samantha has likely had an opinion on what she should feed Charlie, and formula companies seem quite keen to monopolise on parental concerns about largely normal infant behaviours (like spitting up, crying, and variable bowel habits). Frequent formula changes to ‘treat’ these normal baby things tend to just cause misery for everyone, with the poor infant’s little system struggling to adjust to the dietary twists and turns. In most cases, the advice should be to stick to whatever formula the infant seems to want to drink, and give everything time to settle. Normalising normal things is a big part of being a good children’s health professional.

Below is a bit of an overview of the variations in formula products currently available and the general advice around their use.



Soy Formulas

Potential role in cow’s milk protein allergy but big issues with cross-reactivity so not first line when exploring this. Could be used by families with cultural or religious reasons for avoiding cow’s milk. Previous concerns raised regarding phyto-oestrogens but no strong evidence at this stage that this is of clinical concern. Generally advised to avoid in babies under 6 months though.

Goat’s Milk Formulas

No advantage over cow’s milk and generally higher protein content so best avoided unless limited options or cultural issues with cow’s milk products.

Rice Milk Formulas

Can be a good alternative product for children with cow’s milk protein allergy as no known cross-reactivity as for soy.

‘Anti-reflux’ Formulas

These are typically thickened formulas, which can help some babies with significant gastro-oesophageal reflux to posset a little less. Anecdotally, they seem to cause a lot of constipation too, so they’re not for everyone! Reserve for those babies struggling with weight gain.

‘Gold’ Formulas

These formulas contain added fatty acids and other bits and pieces which do try to mimic breast milk a little better, but haven’t yet been proven to be healthier for babies. If parents want to spend the extra money, they’re welcome to, but there’s no issue with sticking with the basics.

Lactose-free formulas

Primary lactose intolerance is extremely rare in infants, so these formulas have a very limited role. Some infants may experience transient intolerance associated with gut pathologies like infective gastroenteritis, wherein these formulas may have temporary benefit. 

‘HA’ (hypoallergenic) Formulas

Some of the larger protein molecules are broken down in these formulas, but there’s usually no real benefit in this. It doesn’t prevent allergies, and in infants being investigated for suspected allergies, we’d use extensively hydrolysed or amino acid based products instead (see below).

Extensively Hydrolysed Formulas (EHF)

These formulas have been extensively enzyme-treated to break down most of the cow’s milk proteins, and are great to trial for babies with suspected cow’s milk allergy (except for anaphylaxis, which requires an amino acid based formula). Some brands are available without a prescription.

Amino Acid Based Formulas

These are used for babies with cow’s milk allergy who cannot tolerated EHF, soy, or rice formulas. They are only accessible on specialist prescription.


Education and Resources

Rachel is in hospital with her newborn baby girl, Sienna. She needs to formula feed due to personal medical issues, but is confused about how to go about it. When you come to complete the newborn examination for Sienna, Rachel asks for some general advice…

Lots of education is needed for new families needing to use formula, and various health professionals can contribute to this education. Midwives and child health nurses are usually best placed to demonstrate proper preparation, administration, and sterilisation techniques, but it’s worth everyone being familiar with the processes to be able to support our families. New parents should also be encouraged to access quality sources of information such as the Raising Children’s Network website, to remind them of the steps and help to answer any further questions. Families should also be encouraged to utilise their Child Health Nurse and/or GP for ongoing support.

The situation above is a good opportunity for the health professional to support and empower families in their choices, dispel a few myths, and encourage safe practices. A few useful things to cover might include…

  • Ignore the marketing, and just pick a formula which is easy to find and comfortable financially. Any subsequent problems, be guided by a health professional, not the lady from yoga, the mother’s group girls, or a Facebook forum.
  • No bottle or teat is necessarily better than any other, provided it’s all sterile and the baby drinks comfortably.
  • Formula powder must be discarded within four weeks of opening the tin.
  • Use the guide on the formula tin to work out how much formula to make up for the baby. Each formula brand/type will be different so read it carefully, especially if changing brands.

General rules for feed volumes required by babies over 24 hours at different ages;

But all babies are different! Paced feeding (see below) can help baby to regulate their intake.

  • Feeding is an important time for carer-child bonding, no matter what the method is. When possible, feeds should occur with limited distractions, so both can enjoy the time together. Eye contact, talking, and touching are all brilliant for baby development during feeds.
  • Swap positions through the feed to stimulate senses equally (mimics swapping sides in breastfeeding).
  • Use paced feeding as much as possible – letting baby rest frequently. Babies will reflexively swallow, and bottles mostly passively deliver the milk to their mouths, so they can end up guzzling a big bottle even if their appetite didn’t require it, potentially resulting in overfeeding, with consequent spitting up and/or weight gain.
  • All equipment must be cleaned and sterilised after every feed, and discarded if cracked or broken.


Selected references

National Health and medical Research council (2012) Infant Feeding Guidelines. Canberra: national Health and medical Research council. (2018). Bottle feeding with formula. [online] Available at:

Australasian Society of Clinical Immunology and Allergy (ASCIA). (2019). Cow’s Milk (Dairy) Allergy. [online] Available at: [Accessed 13 Sep. 2019].

Raising Children Network (Australia).


  • Annabel Smith is a General Paediatrician based on the Central Coast of New South Wales, with interests in public health, the environment, and doctor's wellbeing. She is passionate about breastfeeding, good sleep practices, physical exercise, excellent nutrition, and building family resilience and cohesion to promote long term health and wellbeing for all children.


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3 thoughts on “What’s the formula for formula?”

  1. “with the poor infant’s little system struggling to adjust to the dietary twists and turns”. This suggests that formulas need to be changed gradually or infrequently. Is there any evidence for this?

    1. No hard evidence, to my knowledge – it would be challenging to quantify the effect of formula changes on infants as their behaviour changes so rapidly anyway! Anecdotally, and from my own and colleagues’ experience, rapid changes do appear often to make infants more irritable, and subsequently confuses and stresses their poor parents. Since in the vast majority of cases, babies can tolerate any standard formula, a sensible and compassionate health practitioner should be able to support parents through the normal behaviours of infancy and minimise the ‘need’ for formula changes.

      Thanks for your comments and appreciation!