top of page

How Long Can Formula Sit Out? [Safety Guidelines]

Updated: May 16

As a new parent, taking care of your baby's nutritional needs can be an overwhelming responsibility. If you are reading this article, you are probably considering whether to give your baby formula, either exclusively or as a supplement to breastfeeding.

This might feel like one of the weightiest decisions you've made so far for your child's health, but try not to worry!

Although formula feeding might seem daunting at first, Pathfinder Health is here to help!

In this article, we'll explain all the basics of baby formula so you feel more confident navigating this foundational step in the nutritional journey for your little one.

In this article:

What is baby formula?

Regular formula

Special formula

Is baby formula nutritious for babies?

Feeding your baby with formula

Choosing bottles

Preparing infant formula

Safety precautions

Mixing infant formula

Warming bottles

After your baby's feeding

Storing formula

Baby formula feeding FAQs

Q: Can I prepare formula ahead of time?

Q: How long is formula good in the fridge?

Q: How long can prepared formula sit out at room temperature?

Q: What if my baby doesn't finish their bottle? Is it okay to save leftover formula?

Dealing with formula shortages

Resources for parents

A note of caution: Do NOT use homemade formula

The Takeaway

What is baby formula?

Baby formula is an alternative to breast milk designed for families where (1) parents cannot--or choose not to--breastfeed or (2) babies either cannot nurse or are unable to drink breast milk for medical reasons. It is formulated to meet all of a growing baby's nutritional needs so that it can be used as a full substitute for breast milk.

For purposes of this article, we will be discussing infant formula intended for babies under one year old. After your baby turns one, they are ready to drink whole cow's milk, unless they have an allergy or other health concern.

Regular formula

Most infant formula is made with cow’s milk that has been specially formulated so it has the same balance of nutrients as breast milk but can be easily digested by a baby's delicate tummy.

Nutritionally speaking, it doesn’t matter if you buy name-brand or generic formula. However, you should choose infant formula that is fortified with iron, an essential nutrient for your baby’s growth and development.

Infant formulas come in three types

Different brands of baby formula have slightly different tastes. You might need to try more than one brand before finding one that your baby likes, especially if they have previously been breastfed, so be patient if you are making this transition.

Special formula

Most babies can easily digest cow's milk formula with no adverse reactions. However, 1-2% of infants are allergic to the proteins in cow’s milk and require special formula. Of these babies, up to 50% are also sensitive to soy protein and require an even more specialized formula.