In short: Introduce a bottle once breastfeeding is well established – often after 3 to 4 weeks of exclusive breastfeeding, while for formula the NHS suggests waiting 6 to 8 weeks. Use a slow-flow teat, feed at your baby's pace (bottle almost horizontal, with pauses) and express milk whenever a breastfeed is replaced, to protect your supply.
Author: Eva Birsa, mum and co-founder of Evitas · Updated: 28 September 2026
What is combination feeding?
Combination (mixed) feeding means your baby gets some feeds at the breast and some from a bottle – with expressed breast milk, infant formula or both. Parents choose it for many reasons: going back to work, a partner helping with night feeds, low milk supply or simply more flexibility. Every feed of breast milk counts, so combination feeding is not "all or nothing".
When to introduce a bottle
Breastfeeding and milk production take a few weeks to settle, so experts advise waiting until breastfeeding is going well:
- Expressed breast milk: Nationwide Children's Hospital says it is best to breastfeed exclusively for the first 3 to 4 weeks. If you are returning to work, start offering a bottle 1 to 2 weeks beforehand so your baby can get used to it.
- Formula: the NHS (Best Start in Life) suggests starting mixed feeding 6 to 8 weeks after birth, because exclusive breastfeeding helps build your milk supply.
Offer the first bottle when your baby is calm and alert – not when they are very hungry or tired. If you are unsure, talk to your midwife, health visitor or an IBCLC lactation consultant.
Expressed milk or formula?
| Expressed breast milk | Infant formula | |
|---|---|---|
| Effect on milk supply | you maintain supply by expressing | each replaced feed without expressing lowers supply |
| What you need | breast pump, storage bottles or bags | formula, boiled water, accurate measuring |
| Preparation | warm the stored milk | make up fresh for every feed |
| When it makes sense | when you want to stay with breast milk | when there is not enough milk or you prefer not to express |
Read how to choose a pump in our guide How to choose a breast pump, and how to make up formula in Formula feeding guide.
How to protect your milk supply
- When your baby has a bottle instead of the breast, express at around the same time – this keeps signalling your body to make milk.
- Introduce bottles gradually, not overnight. The NHS warns that stopping breastfeeds suddenly increases the risk of blocked ducts and mastitis.
- To increase supply, the NHS suggests lots of skin-to-skin contact, frequent breastfeeds and expressing about 8 times a day, including once at night.
- For occasional expressing a manual pump is enough, for example the Canpol babies Basic Light; for regular expressing an electric or wearable pump is more practical, for example the Canpol babies SmartSense.
Paced (responsive) bottle feeding
At the breast your baby controls the flow and the pauses. Milk flows more easily from a bottle, so it helps to feed at your baby's pace. UNICEF UK advises:
- Hold your baby close in a semi-upright position so you can see their face.
- Gently rub the teat against their upper lip and wait for them to open their mouth and draw the teat in.
- Hold the bottle almost horizontal (slightly tipped) so the milk does not flow too fast.
- Watch for cues that they need a break (splayed fingers, milk spilling from the mouth, stopping sucking, turning the head) and pause.
- Never force your baby to finish the bottle – this helps them follow their own hunger and fullness.
Never leave your baby alone with a propped-up bottle (NHS).
Which teat and which flow?
For mixed feeding the NHS recommends a slow-flow teat that mimics the flow at the breast. At the same time, the NHS notes there is no evidence that one type of teat or bottle is better than any other – every baby is different and you may need to try a few. For breastfed babies, parents often choose a wide-based teat that encourages a wide latch.
| LOVI Mammafeel | Canpol babies Natural Shape | |
|---|---|---|
| Teat shape | wide, skin-coloured base with a soft tip made from two types of silicone | DuoFlex dual-zone teat: elastic tip and stable wide base |
| Flow (manufacturer's information) | MINI 0m+, SLOW 3m+, MEDIUM 6m+, FAST 9m+, CROSS-CUT 6m+ | mini 0m+ (150 ml), slow 3m+, medium 6m+, fast 12m+ |
| Special feature | sucking study with 102 babies (2023, according to the manufacturer) | milk flows only with active sucking; compatible with the SmartSense pump |
| In our shop | 150 ml bottle, MINI 0m+ teat | 150 ml bottle, 3m+ teats |
Read more about LOVI teat sizes in LOVI Mammafeel bottle: reviews and teat sizes. You will find all options among our baby bottles and bottle teats. How to choose a bottle with colic in mind is explained in Anti-colic bottles.
Who should give the bottle?
Let someone else (a partner or grandparent) offer the first bottles, ideally when you are not nearby – your baby can smell you and expects the breast. The NHS also suggests using a different position from breastfeeding. Once your baby is used to it, anyone close can help, although UNICEF UK recommends that in the early weeks and months most feeds are given by parents or main carers, because babies feel more secure.
When your baby refuses the bottle (or the breast)
- Offer the bottle an hour or two after a breastfeed, when your baby is alert but not crying with hunger (HealthyChildren.org).
- Put a few drops of breast milk on the teat.
- Keep attempts short; if it does not work, try again a few hours later or with a different teat.
- If your baby breastfeeds less well after bottles are introduced, reduce the number of bottles, keep feeding at their pace and ask a lactation consultant for help.
Frequently asked questions
Will a bottle ruin breastfeeding?
Not necessarily. The NHS notes a small amount of evidence that babies learn a different sucking action at the bottle, so it helps to wait until breastfeeding is established and to use paced feeding with a slow-flow teat.
How much milk should I put in the bottle?
With expressed milk, start with a small amount and follow your baby's fullness cues. With formula, follow the pack instructions and your paediatrician's advice, and never force your baby to finish.
Can I mix breast milk and formula in the same bottle?
It is usually advised to give them separately, so no breast milk is wasted if your baby does not finish. Ask your paediatrician.
When should I move to a faster flow?
Age labels are only a guide. Combination-fed babies can stay on a slow flow for longer; if your baby is clearly struggling or feeds take a very long time, try the next level.
Do I need to sterilise bottles?
Yes. The NHS advises sterilising bottles and teats until your baby is at least 12 months old.
Sources
- NHS – How to combine breast and bottle feeding
- NHS Best Start in Life – Introduction to mixed feeding
- NHS – Bottle feeding advice
- UNICEF UK Baby Friendly – Infant formula and responsive bottle feeding
- Nationwide Children's Hospital – Introducing a bottle
- HealthyChildren.org (AAP) – Introducing the bottle
- LOVI – Mammafeel
- Canpol babies – Natural Shape bottle with dual-zone teat
This content is for information only and does not replace advice from your paediatrician.
