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Can I mix breast milk with formula?

First of all:


Breast milk, is liquid gold. If you are breastfeeding, either exclusively or combo, CONGRATULATIONS, you are doing an amazing job. ♡

Now, many moms ask me: if I give both anyway, can I mix them?

Theoretically, if the formula is correctly prepared, and mixed with breast milk afterwards... Well, yes it can be mixed. Now, is it the best thing to do? NO.


By feeding responsively, on demand, we follow our baby's cues. They won’t always take all we offer, so if we mix formula with breast milk and not all of it is taken, we are wasting breast milk. And this HURTS, only we know how much it hurts!

Let's say your baby drinks 1 oz of the mixture and then she’s done, you mixed 1 oz of breast milk with 1/2 oz of formula: she would have had the whole ounce of breast milk only, which would have been better, and you wouldn’t waste anything.

That's why it's best to offer whatever breast milk you have available first, and then formula if she wants more.

Some moms also ask me if they can add powdered formula to their breast milk to make it more nutritious: PLEASE DON'T DO THIS ⚠


▪️Powdered formula is not sterile and needs to be prepared in a certain way.

▪️ The mixture would have an overload of solutes which may be too much for your baby's kidneys

▪️ You will change the perfect composition of breast milk

If you have any questions about feeding: formula, breast milk, solids... I can help! Book a virtual feeding consultation here.

Paola Vallarino IEP IBCLC CBS. Founder of Mamas Au Lait Lactation.

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