Mixing Formula and Breastmilk: Fundamentals to Know
As a parent, when it comes to feeding, no matter how many books, videos, or suggestions you go through, every second is new. And it all varies from mother to child, too!
Some moms prefer to breastfeed exclusively, others formula feed, while some find more value in combination feeds – by combination feed I mean mixing formula and breastmilk.
The combination feeding style can either depend on some unavoidable situations that enforce such decisions, or it is a personal choice – both are valuable. If your little one is healthy, there’s no guilt in feeding them with combination feed, either.
So, to ease your doubts about combination feeding, let’s talk pros and cons, and I’ll provide useful information about mixing formula and breastmilk, how long it lasts, and precautions you should take.
Table of Contents

Can You Mix Formula and Breastmilk?
Ladies, the answer is “YES”. There’s no harm in mixing formula milk with breast milk. You can mix it in the same bottle.
- We all are aware of the exceptional health benefits of breast milk. It offers good nutrition and even provides antibodies that protect your baby from infections. Also, breastfeeding helps mothers fight postpartum depression.
- On the other hand, formula milk is also a great alternative that provides sufficient minerals, nutrition, and vitamins to foster development.
So, it’s completely alright to mix formula and breast milk. All you need to do is be careful with the formula measurements first. Ensure you read the guidelines about preparing formula milk according to your little one’s age.
Why Do Mothers Combination Feed?
For some mothers, exclusive breastfeeding can be tough. And that’s where combination feeding comes in. Here are some scenarios where combination feeding becomes a necessity:

- Low Milk Supply: Sometimes a mother struggles to produce enough milk to satisfy the baby. So, mixing breast milk with formula keeps the baby full and compensates for the nutritional value too!
- Resuming Work: Isn’t it hard to say goodbye to your little one as your maternity leave ends? However, you can guide your caretaker with bottles or combination feeds your baby will need. I suggest you breastfeed your baby before leaving for the office and prepare a set of bottles for the day.
- Multiple Babies: A few mothers are blessed with twins and even triplets. And some of us may already have other babies to take care of. So, combination feeding can ease that burden a little. This way, your little ones will not get cranky, and the household becomes more manageable.
- Break: Yes, we mothers do need a break. All those sleepless nights can really take a toll on anyone. But, by mixing formula and breastmilk, you can ask your partner or relative to help feed the baby while you rest.
- Premature Babies: Many health experts suggest that a combination feed works well for premature babies. The extra nutrients can help them recover and develop at a good pace. If you’re taking care of a preemie, please follow your doctor’s advice strictly for healthy feeds.
- Transitioning to the Bottle: When the time comes for transition, many parents try to get their babies used to the bottle. And mothers who wish to drop their milk supply with time opt for combination feeds.
Another post that might interest you: Advantages and Disadvantages of Breastfeeding After 2 Years
How to Mix Formula and Breast Milk
To prepare the mix, first, get your formula milk ready. In the formula powder, add the instructed amount of water and prepare the milk.

Now that you have prepared formula milk, it’s time to add the breast milk. Give it a stir and mix it well. The feed is ready for use!
CAUTION: A few years ago, a mother asked me, “Can I mix formula with breast milk instead of water?” And it took me a minute to understand. The answer is a clear big “NO” by the way.
Always mix the formula with water, and only after do you add in the breast milk! Please do not do it otherwise!
Things to Remember
Before you prepare the milk, please keep these points in mind:
- Maintain the right temperature to keep the nutritional value of the milk intact.
- Do not add extra water, over the recommended dosage.
- Also, adding less than the recommended amount of water to the formula powder can lead to digestive issues and dehydration. Please stick to the instructions.
Back when I was still a new mother, I asked another mom if it was ideal to mix formula with breast milk and if a combination feed works well.
She said (and I’m paraphrasing here):
“I have been practicing the formula and breast milk combination from when my baby was 9 weeks old. I am not an over-supplier, so, I pump breast milk and mix it with formula. During some hours, my husband feeds the baby with a combination. That way, I get some rest and my baby is also full. She sleeps very well after the feed, too.”
Mixing Formula and Breast Milk: Pros and Cons

| Pros | Cons |
|---|---|
| For mothers struggling with breast milk supply, combination feeding helps to deliver equal nutrition to the baby. | With regular combination feeding, your breast milk supply will gradually diminish. |
| Milk from combination feeding can be stored for longer hours. | You may have to deal with milk wastage in case your baby refuses the bottle. |
| It makes the transition from breastfeeding to bottle feeding a lot easier. | |
| Mothers can share feed responsibility with their partners or relatives and enjoy breaks. |
There are enormous benefits to combination feeding, but it has its weak points too. However, if you store it well and follow good guidelines for use, the wastage can be reduced.
How Long is Breast Milk and Formula Mixed Good for?
- After you prepare the mixture, it’s best if you use it within the hour. Post that, please discard the milk.
- If you are preparing the mixture to store it, you can keep it in the fridge for 24 hours (and that’s only if your baby has not yet taken a sip of it).
Note: If your baby drinks a little of the milk and refuses the bottle or does not finish the milk completely, then, please discard it. Do not store milk that’s already been used.
Takeaway on Combination Feeding
Be it breastfeeding, formula feeding, or a combination, they all work well for your little ones. It completely depends on how you want to feed your baby.
My only advice is that you follow safety guidelines to prepare the feed.
If you feel that your little one isn’t responding well to the combination feed, or has been refusing bottles lately, do not hesitate to contact your pediatrician or lactation expert.
Until then, happy feeding, ladies.
