Combination feeding - Breast milk and formula

Combination feeding or mixed feeding is when you combine both breastfeeding and formula milk when feeding your baby.

Breast milk production

The more you breastfeed, the higher the amount of milk you'll produce.

If you begin giving formula to your baby while you are breastfeeding, unless there is a medical reason, they'll take less of your breast milk. This means your body will produce less milk.

Exclusive breastfeeding - giving only breastfeeds and no formula - helps make sure you have enough milk supply for your baby’s needs. Introducing formula feeds can cause your milk supply to reduce.

Feeding in early weeks

Sometimes, mothers breastfeed with the desire to give their baby both breast and formula feeds. Even if this is your final goal, try exclusively breastfeeding for the early weeks of your baby’s life if possible. Breastfeeding in the early weeks is important for building up your breast milk supply. It's also useful if your baby develops an allergy to cow’s milk formula.

Before you consider combination feeding, talk to your local breastfeeding support group for help and advice.

Challenges of formula feeding

If you plan to combination feed, it may take time for your baby to adjust to feeding from both the bottle and the breast.

Bottle-feeding and breastfeeding are very different for your baby. Be patient and allow your baby plenty of time to learn how to drink from a bottle.

Breast milk supply

When you begin giving formula to your baby, they will take less of your milk. Your body then makes less milk as a result. This can mean that you may unintentionally bring breastfeeding to an early end.

By breastfeeding as many times as you can over 24 hours, you will maintain your milk supply. This means you will be able to breastfeed for longer. Even if you are bottle-feeding, try giving your baby your breast at each feed. This will help regulate your supply.


Because formula milk is not as digestible as breast milk, your baby may experience more digestive discomfort and wind. They may also get constipated.

Breastfeeding issues

Possible breastfeeding challenges such as sore nipples may develop. This is because the type of sucking action needed to breastfeed is different from that needed to bottle-feed. Your baby also uses different oral muscles for bottle-feeding and this can make breastfeeding more difficult.

Introducing formula can mean your baby feeds less at the breast. As a result, your breasts can become engorged. If this happens, it's important to remove milk by hand expression or pumping.

Your baby may learn to like the fast steady flow of the bottle and get frustrated while breastfeeding due to the initial slower flow from the breast.

Things to consider when formula feeding

When considering formula feeding, be aware of:


It is important to safely prepare your baby's formula feed

Paced bottle-feeding

When bottle-feeding your baby, it's important to pace the feed. This is so that your baby can control both the amount of feed taken and the speed of their feeds. Although paced bottle-feeding works well for all babies, it works especially well for breastfed babies.

Paced bottle-feeding is a great way for the baby and carer to get used to bottle feeding.

Follow the steps below to get started:

  1. Sit your baby on their carer’s lap.
  2. Hold the bottle almost level and offer the teat in the same way you would the breast.
  3. Tickle the top lip and allow the baby to take the teat into their mouth and suck.
  4. Tilt the bottle slightly towards the baby and when they pause, tilt the bottle down to allow the baby to rest for a moment.
  5. Repeat until the baby has taken the full feed.

This works well because your baby can control the milk flow. If your baby is over 6 months and doesn’t like a bottle, you can use a cup with handles on it. Only put a small amount of liquid into the cup so that any spills are easy to clean.

Watch a video on how to give a paced bottle feed below.

Getting help

Breastfeeding can take time and patience to learn. There is lots of support on offer from public health nurses and lactation consultants.

Page last reviewed: 28 November 2018
Next review due: 28 November 2021