Mixed feeding – also called combination feeding – is where you combine breastfeeding your baby with bottle-feeding – filling the bottles with either formula milk or (expressed) breastmilk.


There are a number of reasons you might choose to start mixed feeding, says Jackie Hall, a Manchester-based International Board Certified Lactation Consultant (IBCLC), including:

  • You're breastfeeding but want to be able to give the odd bottle to give of expressed milk or formula milk, so your partner can help with feeds
  • You're breastfeeding but having initial difficulty establishing your supply and want, or have been advised, to give your baby some formula milk alongside
  • You're breastfeeding but are going away or going back to work, so your baby may need to take a bottle (of expressed breastmilk or formula milk) from someone else while you're away from them
  • You're currently breastfeeding but want to start giving your baby formula milk more often, and move away from exclusive breastfeeding
  • You've been expressing breastmilk and feeding it your baby (perhaps because they were born prematurely) and you now want to starting moving them (either exclusively or partially) to nursing at breast

If you're thinking of starting mixed feeding, you'll need to know what the experts say about it, how to do it – and when, how it might affect your baby and what it could mean for your own milk supply. Read on to find out...

Mixed feeding with breastmilk only

Much of the advice in this article is centred on mixed feeding using formula milk – so, for example, there is info on how mixed feeding can affect your milk supply, because you'll be feeding less frequently at the breast.

But, of course, it's perfectly possible to do mixed feeding without introducing formula and only using breastmilk in your baby's bottles. (And your milk supply shouldn't be affected, as frequent expressing will keep your supply boosted.)

What to consider before you start mixed feeding

Before you start mixed feeding, it's important to be sure you're clear why you're doing it, and that, where possible, it's a positive decision, rather than a negative one.

"If you are experiencing a specific breastfeeding problem which has reduced your confidence and is causing you pain or distress," says Jackie, "do seek out a skilled breastfeeding counsellor before you make any decisions about introducing formula. It’s so easy to look to formula as the quick and easy answer to a problem, but it’s really important to make an informed decision about this."

It's also worth knowing that there's a lot to be said for introducing mixed feeding as gradually as possible – you'll find it more comfortable (your breasts won't get so engorged with 'unused' milk) and your baby will get the benefits of breastmilk for longer.

More like this

"I would encourage anyone who is considering introducing formula to learn as much as they can about how breastmilk production works, and about the differences between formula and breastmilk in relation to health," says Jackie.

It’s important to reiterate that any amount of breastmilk is great for your baby – the more breastmilk, the more protection
Jackie Hall, lactation consultant

How soon can I try mixed feeding?

The WHO (World Health Organisation) guidelines recommend giving your baby breastmilk exclusively for 6 months but we know not everyone can – or wants to do that – for whatever reason.

That said, it's generally accepted that it's best to wait until breastfeeding is firmly established before introducing a bottle. Opinions vary on when that's likely to be but, as a rough guide, that's unlikely to be before 6 weeks and, if you can wait a few weeks longer, so much the better.

If you're introducing mixed feeding because you're going away or going back to work, then it's wise to start a few weeks before your departure/back-to-work date, so building in time for you both to adjust.


What do I need to do mixed feeding?

Whether you're planning to mix-feed with formula or expressed breastmilk, you'll need to make sure you have:

  • feeding bottles
  • formula milk or an electric/manual breastpump
  • a steriliser

Before you rush to the shops, though, it's worth considering that, if your baby's already over 6 months old and can drink from a cup or beaker, you may not need bottles at all.

OK, so how do I begin mixed feeding?

It's best to introduce the bottle feeds gradually, says Jackie – to give your breasts time to adjust to making less milk (assuming you're not also expressing breastmilk).

Start by replacing 1 breastfeed with a bottle feed, and do this for at least 2 to 3 days, at a similar time of the day – whatever time works for you – before introducing any other bottle feeds
Jackie Hall, lactation consultant

"Your body will begin to make less milk," says Jackie, "as there will be less emptying of the breast. But to begin with, your breasts may full uncomfortably full.

"If your breasts become full to the point of pain (engorged), it’s important that you use your hands to express some of the extra milk – even for just a few seconds – to keep your breasts comfortable. Otherwise, you may end up with blocked ducts or mastitis."

What if I've been told to 'top up' with formula at each breastfeed?

If you've been advised to ‘top up’ with formula during 1 or more feeds, rather than replacing an entire feed – maybe because you're having some difficulty getting breastfeeding established – it's best to breastfeed first, then offer the formula, rather than the other way round.

Doing this is likely to extend the gap between breastfeeds, as well as signalling to your breasts to make less milk. That's fine if your intention is gradually to drop breastfeeds entirely and replace them with formula. But, if you're using ‘topping up’ as a temporary measure and want to return to exclusive breastfeeding, you'll need to express milk between feeds to increase the amount of milk your breasts make and so keep up your milk supply.

How to introduce a bottle to your baby – plus tips on avoiding 'nipple confusion')

Some babies can become confused between breast and bottle, Jackie acknowledges, as feeding from a bottle is a completely different mechanism from the normal biological feeding from the breast.

"In order to reduce this confusion," she advises, "it’s really important when offering breast milk or formula from a bottle to your baby that you do this in a responsive way. I suggest that you:

  • Sit your baby semi-upright
  • Use the slowest flow teat and allow the baby to draw the teat into their mouth (rather than putting it in yourself) mouth
  • Keep the bottle at the lowest possible angle to prevent milk gushing out too fast – but making sure there is still milk filling the teat
  • Take lots of pauses throughout the feed to put your baby in control
  • Never make your baby finish the whole bottle if no sign that they want it. 

"I feel that the this paced bottle feeding," says Jackie, "together with using breast compressions when your baby is feeding at the breast, to make your milk flow faster – can help to avoid some of the confusion that can happen between breast and bottle."

If your baby is reluctant to take the bottle:

  • Wait till your baby is relaxed and happy and not extremely hungry
  • Ask someone else to hold the bottle, so your baby can't smell your breastmilk
  • Soften the bottle teat before a feed with warm, boiled water
  • Try a different teat

Will mixed feeding affect my milk supply?

Yes, unless you're also expressing your breastmilk. That's because breastmilk works on a supply and demand basis – so the less often your baby is feeding at your breast, the less milk they will keep producing.

"Mixed feeding will always affect your supply as your body will only make milk according to how much demand is being put in at the breast," says Jackie, "and consequently, how much emptying is going on.

"As milk comes out of the breast, your body makes more on that particular side. If formula is offered instead of feeding at the breast, your body will make less milk."

Which is – in theory at least – all perfectly fine, if you are breastfeeding less often: your supply should still match your breastfeeding needs.

"But," says Jackie, "it's true that some women do find it more of a challenge to keep breastfeeding going, if they start offering increasing amounts of formula to their baby."

For that reason, it's always best to proceed gradually with mixed feeding and be sure that, if you start to offer your baby more and more formula, you're ready for the possibility that you may find you need to give up breastfeeding sooner than you'd though.

What if I give my baby breastmilk in the day and formula at night: will that affect my supply?

Yes, it probably will, if you do it on a regular basis (say, you accept your partner's offer to do every night feed or even most of them).

"If you baby feeds at night, these feeds are critical for milk production," says Dr Danielle Prime, a lactation researcher who works for Medela. "If you skip this feed in the early months, so your partner can night-feed, it may result in down-regulation of your milk supply."

If I’m doing mixed feeding with formula, should I use a particular type?

"If you are giving formula to your baby," says Jackie, "it is recommended to use only the 'first milks', which are whey-based."

"As a lactation consultant, I can't recommend any particular brands. And I would also say that 'second milks', follow-on milks, and 'goodnight milks' are not recommended and not necessary."

How will mixed feeding affect my baby?

You might notice a few changes in your baby when you start to add formula to their diet (though not necessarily ones you might have been expecting – like finding they sleep more!).

"Babies often have change of bowel patterns when formula is given as well as breastfeeding," says Jackie. "Poos can be more formed, darker in colour and often smellier than the loose, yellow stools of a breastfed baby. Even 1 bottle of formula can change your baby's bowel pattern."


As for sleeping longer, "there is no real evidence to suggest that babies sleep more they're offered formula," says Jackie. "But some mothers would disagree. I think that's because formula, which is made from cows' milk, has a higher ratio of casein to whey protein than human milk, so it can take a baby longer to digest, and may sit in the baby’s tummy longer, meaning they might not be hungry again so quickly.

"Also, with bottle-feeding, many babies sometimes override their feelings of fullness, so may take more milk than they need, and consequently become overfull, which could potentially cause a baby to sleep longer – even though this isn’t biologically normal."

Any other changes? "Yes, maybe some extra wind," says Jackie."Babies expect to feed frequently and digest milk rapidly. If a responsive, paced bottle isn’t used (see How to introduce your baby to a bottle, above), babies can potentially become more ‘windy’."

Can I go back to exclusive breastfeeding if I change my mind about mixed feeding?

If you feel you've moved to mixed feeding too soon, yes, you can go back, says Jackie, but you may have to work at it with some determination.

"Nothing is set in stone," she says, "so it’s certainly possible to boost your supply again, if you decide to."

You'll need to do lots of regular expressing during the day and night, and lots of skin-to-skin cuddling with your baby. It's not easy but if you find people to encourage and support you, including, preferably, a skilled breastfeeding counsellor, it can make all the difference.

'How I went back to exclusive breastfeeding': one mum's story 

Mum Laura B in our Facebook community shares how she managed to return to exclusive breastfeeding with her mixed-fed premature baby:

"I had Amelie at 36 weeks. She was breastfed exclusively at first but it was a real battle as she lost too much weight. So we had to mix-feed while she was in hospital.

"Once we were home, it took a good few weeks to drop the formula. I needed lots of perseverance, and support from my local La Leche League group. So many times I was close to giving up, as she would just refuse my milk. 

"But we spent a few days skin-to-skin in bed and got it back. We kept going until I went back to work full-time when she was around 11 months."

About our expert Jackie Hall:
Jackie is an IBCLC (International Board Certified Lactation Consultant) and mum of 3, based in Manchester. She is founder of The Breastfeeding Companion which offers extensive free resources, including videos, on all numerous breastfeeding-related topics. She has a Bachelor of Nursing degree and has worked for the NHS as a Registered Nurse, Specialist Community Practitioner (Health Visitor), and, for the last 8 years, as an Infant Feeding Coordinator/Breastfeeding Specialist.

Pics: Getty




Helen Brown
Helen BrownHead of Content Delivery

Helen is author of the classic advice book Parenting for Dummies and a mum of 3. Before joining MadeForMums, she was Head of Community at Mumsnet and also the Consumer Editor of Mother & Baby.