How Long Is Formula Good For?

As an expectant parent, there are a lot of things you need to learn about, like infant formula. You and your partner may have decided to use only formula, or you may have decided to use a combination of both concentrated formula and breastmilk.

No matter what you need to learn, we’re here to help. We care about the health of expectant mothers and their babies, and we want to help them and their partners learn everything they need to know about their new addition. Knowledge can help you plan and reduce some of the stress about this new phase in life.

Although formula can be a great alternative or addition to breastfeeding, it does have a shelf-life. We want to ensure our little ones are healthy and that their food is good for them, and expired formula can be unhealthy and filled with bacteria.

With many foods, we can just look at the expiration date and determine when they typically go bad. Since it’s an estimate, it can happen a few days before or a few days after, but it still happens around that time.

Powdered infant formula is a little different. While it’s true that there are expiration dates, usually, these dates apply to sealed formula containers. This means that opened containers of formula powder and mixed formula can have different expiration dates.

So how long can formula stay good for? Let’s find out.

What Types of Baby Formula Are There?

There are three general types of baby formula that you can buy. They typically fall into two categories: ones that you can buy ready-to-use and ones that need to be mixed with water.

Ready-to-feed formula is simple. All you need to do is pour the formula into your little one’s bottle of choice and feed it to your baby. It’s as easy to use as a supplement or alternative to pumped breastmilk if you don’t have time to pump. 

This formula may be a good alternative to use if you don’t have the time for pumping or mixing formula or if you need some in an emergency. However, it may not last as long as other groups of formula.

The other two types of formula are:

  • Concentrates, which need to be diluted with warm water
  • Powders, which need water to make them liquid so your little one can drink it

Mixing Baby Formula: What To Know

It’s important to mix in the correct amount of water since too much water will reduce the amount of nutrients that your little one gets. If you don’t add enough water, it may lead to dehydration and could disrupt your baby’s 

When you mix formulas, you will want to check that the water you add is clean, so it’s important to test tap water before using it. You can also use boiled water as long as you let it cool down completely first. Bottled water can be okay, but it can easily get contaminated, so it’s better to avoid it.

It’s also important to ensure that the baby bottles and any other products used for feeding are sterilized after they are first bought and washed thoroughly after each use.

Formula can also be served without warming it, although some babies might respond better to warm formula. The best way to warm a bottle is to let it sit for a few minutes in a pot of hot water. Microwaving it will heat the formula unevenly, which can end up burning your little one’s mouth. You can also use a bottle warmer.

Always check the formula first to make sure it isn’t too hot. You can squirt a little onto your wrist to test it.

How Long Is Formula Good For?

The length of time that formula can last will depend on three things:

  • Whether it’s unopened
  • Whether it’s been mixed
  • Whether part of it has been eaten

Another factor can be how it’s stored, which can also apply to breast milk. Formula that isn’t stored properly won’t last as long, so it’s important to follow any instructions on how to store formula that you may find on the packaging.

Before you purchase the formula, it is generally a smart idea to check the seal. If it’s been broken, it can be unsafe to use since. A broken seal could suggest the formula has already gone bad, or perhaps something else may have contaminated it. Open containers of formula also go bad much faster than sealed containers.

If the formula is past the expiration date or you’ve had it open for longer than recommended, you shouldn’t use it to make food for your little one. It may have bacteria or other issues that can upset your little one’s stomach. It would be like drinking sour milk, so take care and pay attention to the expiration times.

How Long Can I Keep Unopened Infant Formula?

Generally, unopened formula is safe as long as it isn’t past the expiration date on the package. However, the expiration date will vary depending on when you buy it, the brand you buy, and what type of formula it is.

If the formula is past the expiration date, it’s better to throw it out since it can’t be used for bottle feeding. It can become contaminated, and expired infant formula also loses some of its nutritional value. Since babies grow a lot, especially in their first year, they need those nutrients, so a new can is the better option.

It’s also best to keep formula stored indoors, in a cool, dry place unless the packaging instructs that it be stored in the refrigerator. If you have any questions about whether you can use a container of formula or how to make the baby formula last, it’s best to get medical advice from your pediatrician.

What About Formula That’s Open?

Opened formula doesn’t last as long as a sealed container of formula, and the length of time that you can use it will depend on the kind you have.

Ready-made formulas and concentrates should be stored in a refrigerator after being opened since they’re already in their liquid form. Like breastmilk, they will spoil if they are left out for more than two hours at room temperature, and they should be used within 24 hours. Otherwise, they aren’t good anymore.

Powdered formula is a different story. Since it’s dried, it can last longer, but it needs to be stored in a place that is dry and cool, like an indoor pantry. Usually, an opened powdered formula can last for a month after it is opened. You should probably throw away any powdered formula within a month of opening.

However, it’s always essential to check the can for other instructions. You can also write the date that you opened it on the lid so that you have a visible reminder of when the formula is past due.

Can I Save Formula That’s Been Mixed?

If you decide to use powdered formula, you might wonder if you can save it after it’s already been mixed. Like breastmilk, ready-made formula, and concentrate, you can generally save it as long as you keep it in the fridge.

Formula can last at room temperature for about two hours, but if you won’t be feeding your baby within that time frame, it’s time to put it in the fridge.

Mixed formula in the fridge should last for 24 hours. If you’re feeding your little one at night, you can prepare bottles beforehand so that all you need to do is grab one from the fridge and feed your little one. It can make night feedings easier to have a previously prepared formula.

However, if you make too much for one night, you should be sure to try to use it the next day before that 24-hour period is up.

What If My Baby Has Leftovers? Can That Be Saved?

If your little one doesn’t finish their whole bottle, you may be thinking about hanging onto it for later. For your baby’s safety, though, it’s better to toss leftover formula out.

Babies, like us, have bacteria in their mouths. While your baby drinks, the bacteria in your baby’s mouth spreads to the nipple of the bottle, and it can multiply after your little one is done and get into the formula. It can actually cause the formula to spoil faster.

This is also why it’s critical to always wash bottles in between each infant feeding.

Keeping Your Little One Well-Fed

Feeding a bottle of formula to your little one, breastfeeding, pumping, or any mixture of those options are fabulous ways to keep your baby happy and healthy. As long as your little one is getting the nutrients that they need, you and your partner have the option to do one or both when feeding your little one.

However, to avoid upset tummies, it’s essential to make sure that the formula that you’re using is safe and healthy for your baby. Once it’s past the expiration date, it doesn’t have the same nutritional value, and it isn’t suitable for your little one.

If you need to find more information about babies or pregnancy or are looking for products that can provide some postpartum support, The Mommy Care Kit is here to help.


Formula Feeding FAQs: Preparation and Storage (for Parents) | Nemours KidsHealth

How to Prepare and Store Baby Formula | Cleveland Clinic Health Essentials

Infant Formula Preparation and Storage | Nutrition | CDC