What is formula?

Formula is an alternative to breast milk. It’s made from a special dried-milk powder. Most infant formula products are made from cow’s milk, with extra vitamins and minerals. Formula also includes fat from vegetable oils.

Formula powder is mixed with cooled boiled water and offered to your baby in a bottle. You can also buy ready to drink formula.

Infant formula feeding supports your baby’s growth during their first 6 months. Once they reach 6 months, they can start eating solids as well.

The protein in most infant formula comes from cow’s milk.

Some formula products use protein from other sources like soybeans or rice. These specialty formulas are suitable for babies who cannot tolerate cow’s-milk protein or lactose. Specialty formulas should only be used under the guidance of a healthcare professional.

How is formula different from cow’s milk?

Babies under 12 months should not have cow’s milk as their main drink because they can’t digest the protein and salt very well. It can also make their blood low in iron.

Small amounts of cow’s milk can be mixed with your baby’s food after 6 months of age.

How is formula different from breast milk?

Both breast milk and formula are complete foods for babies for their first 6 months.

One of the main differences between formula and breast milk is that your breast milk contains antibodies, which help protect your baby from illness. Your baby is not born with a fully developed immune system.

The content of breast milk naturally adapts and changes according to your baby’s needs. The content of formula milk stays the same, but you can buy different types as your baby gets older.

Breast milk also has less protein than formula milk.

Why might I give my baby formula?

There are many reasons why formula might be the best option for you and your baby. You may:

• be unable to produce enough breast milk for your baby’s needs
• have a health condition or take medication that means you can’t breastfeed
• not always be with your baby, such as if you are returning to work
• not have the option to breastfeed, such as dads, transgender or non-binary parents, or you’re an adoptive or foster parent, or kinship carer
• have experienced sexual abuse or another type of trauma that involved your breasts which means that you choose to feed your baby using formula
• choose not to breastfeed for another reason, or to stop breastfeeding before 12 months

If you want to breastfeed but have difficulties or do not produce enough milk another option is mixed feeding. Mixed feeding is when your baby drinks some breast milk and some formula.

What are the different types of formula?

Most infant formula are made from dried cow's milk with added vitamins, minerals and vegetable oils and other nutrients.

There are several ways that formula is manufactured:

• milk-based formulas — based on cow's milk
• soy-based formulas — based on soybeans
• specialty formulas — made from cow's milk which has been 'predigested' and the protein removed, broken down or reduced. Hypoallergenic formulas are also available.
• added compounds — may include prebiotics, probiotics and antioxidants or long chain polyunsaturated (LCP) acids. Manufacturers claim these make the formula more like breast milk. But this doesn't mean your baby can digest these compounds in the same way as if they were breastfed.

In Australia there are 3 main types of infant formula:

1. Stage 1 or starter formulas: these are suitable for babies aged up to 6 months.
2. Stage 2 or follow-on formulas: these are for babies aged 6-12 months and they often have a higher iron content. You don’t have to change to a follow-on formula.
3. Specialty formulas: these are designed to suit babies with a food protein or milk allergy or another form of digestive, malabsorption or gut problem. Anti-reflux (AR) formulas have a thickener added that helps to keep the milk in the baby's stomach and reduce the likelihood of reflux. Specialty formulas should be used under the guidance of a health professional.

You might also choose a specialty formula for cultural or religious reasons.

Specialty baby formula can be expensive. Speak with your doctor or baby’s paediatrician about getting a prescription since this can help to reduce the cost of feeding your baby.

All formula sold in Australia needs to meet strict nutritional and hygiene standards. After the age of 12 months your baby doesn’t need formula.

Can babies be allergic to formula?

Some babies are sensitive or allergic to cow’s milk-based formula. The protein in cow’s milk might cause your baby to have a reaction.

Your health professional might suggest a hydrolysed formula instead. Hydrolysed formula contains cow’s milk protein that has been broken down into smaller particles.

How can I tell when my baby is hungry?

It can be hard to know when your baby is hungry or if there is something else making them fussy. Sometimes you won't know for sure that your baby is hungry until you offer a feed.

Babies usually cry when they are hungry. Placing the teat of the bottle in their mouth will calm them and they will start sucking.

Try to hold your baby in your arms as you would if you were breastfeeding. Cuddle them, look into their eyes and look out for their cues or signals.

Your baby will suck and swallow steadily. They may look as if they're concentrating on feeding. Your baby’s hands could be clenched and their whole body looks like it's focused on sucking. As they fill up, their hands and body become more relaxed.

Breastfed babies regulate their own milk intake. They suck when they're hungry and stop sucking when they're full. In comparison, if you are using formula in a bottle, you have more control of how much milk they drink.

Try to offer as much milk as your baby needs. This will change as they grow. Use the information on the formula container about how much a baby needs for their age or weight as a guide. Your baby may need more or less than it says on the label.

When your baby has had enough, they will usually pull away from the teat to let you know they are full. You may notice that their sucking slows down and they have longer pauses between sucks.

Other ways your baby might show you they have had enough could be milk starting to pool in their mouth or they may vomit up some milk.

How to prepare formula

Before you start:

• Read the information on the container.
• Check how much water and how many scoops of powder you will need to mix.
• Wash and dry your hands well.
• Make sure you have a clean sterilised bottle.
• Make sure you have a clean surface and space to work.

You can store sealed bottles of boiled and cooled water in the main part of the fridge for up to 24 hours. Do not store bottles in the fridge door as the temperature may be higher. Just before your baby’s feed you can add the correct number of formula scoops.

Preparation and hygiene tips

Only use bottles and feeding equipment that have been washed and sterilised.

Make up each bottle as your baby needs to be fed. If you do need to store formula, place it towards the back of the fridge where the temperature is coldest.

If your baby has not finished the formula in the bottle after an hour, throw away what is left. Formula and bottles become contaminated once the baby has fed from them. Do not store partly used bottles of formula.

If you’re going out, transport the cooled, boiled water and formula powder separately. Mix the 2 just before feeding. Otherwise, keep the prepared formula cold in an ‘esky’ (cold storage container), baby bottle pack or cold bag.

Never warm formula in a microwave. This can cause the milk to heat unevenly and lead to burns. Instead, warm up each bottle in a jug of hot water. Bottle warmers are another safe option. Follow the instructions provided.

Always make up formula according to the instructions on the tin. If the formula is made too weak, it can cause poor growth and your baby will be hungry. If it is too strong it can lead to constipation and your baby could become overweight.

Resources and support

Check with your child health nurse if you’re unsure about how much formula to offer your baby. They will guide you on the correct amount for your baby’s age and weight.

The Sydney Children’s Hospital has more information about different types of infant formula.