Formula feeding and sleep

This guide is general information only and isn't a substitute for medical advice. If you're concerned about your child's health, or they're unwell, please see a doctor.

You'll hear that formula-fed babies sleep longer. It's one of those claims that is partly true, frequently overstated, and often used to make parents feel they've chosen wrong. Here's a level-headed look at what formula does and doesn't change about sleep.

The one real difference

Infant formula is digested more slowly than breastmilk. That is the actual mechanism behind the folklore, and it is why Raising Children says that a formula-fed baby aged over six months is unlikely to be waking at night because they're hungry.

What it does not mean is that formula guarantees longer sleep. Night waking has many causes, and hunger is only one of them.

It's also worth retiring the guilt that tends to attach to this question. Whether you formula feed by choice or by necessity, it is not the reason your baby is or isn't sleeping, and the families with the worst sleep are spread evenly across both camps.

Night feeds and formula

For formula-fed babies, you can think about phasing out night feeds from around six months of age. Raising Children describes a gradual approach: if your baby is having 60 ml or less at a night feed, you can stop that feed and resettle; if they're having more than 60 ml, you can reduce the volume by about 20 to 30 ml every second night over 5 to 7 nights, resettling after each smaller feed, until you reach 60 ml or less and can stop.

Before you change anything, it's a good idea to talk with your child and family health nurse or GP for advice that suits your situation. If you have any concerns about your baby's growth, weight gain or feeding, don't start night weaning until you've talked it through with them.

The bottle-to-sleep trap

Don't put your baby to bed with a bottle. Settling a baby to sleep with a bottle can cause tooth decay, because the lactose in milk feeds the bacteria that cause decay and there's less saliva to protect the teeth during sleep. It is also a choking risk.

A bottle at the very end of the routine can also become the thing your baby needs in order to fall asleep, which tends to reappear at every overnight wake. Move the feed earlier in the wind-down if you want to loosen that link.

Safe sleep is the same

Formula or breastmilk, the rules don't change: back to sleep, in their own safe sleep space, in a clear cot.

Sources

• Raising Children Network, Night weaning and phasing out night feeds
• Raising Children Network, Tooth decay in babies and children
• Red Nose Australia, Six safe sleep recommendations

Last updated: July 2026. Sources include Red Nose Australia and Raising Children Network where cited above. This guide is general information only. For individual concerns, see your GP or child health nurse.