How Long Does Infant Formula Last?
Prepared infant formula lasts 24 hours in the fridge. At room temperature, use it within 2 hours of mixing and within 1 hour of the start of a feeding, then discard what is left. Use opened powder within 1 month.
Infant Formula — prepared
shelf life- Opened, powder: 1 month in the pantry
- Opened, ready-to-feed or concentrate: 48 hours in the fridge
Fridge at 40°F (4°C) or below · freezer at 0°F (−18°C). Freezer times are for best quality; frozen food stays safe longer.
Infant formula comes as powder, liquid concentrate or ready-to-feed liquid. Powdered formula is not sterile, and once any formula is mixed or opened it is a warm, nutrient-rich liquid in which bacteria multiply fast. Because babies are highly vulnerable to infection, the time limits are strict and much shorter than for ordinary milk.
How to store infant formula
- Wash your hands and use clean, sanitized bottles, and measure water and powder exactly as the label directs; adding extra water is dangerous for a baby.
- If you are not feeding right away, put freshly prepared bottles in the back of the fridge immediately and use them within 24 hours.
- Store the powder container with its lid on tight in a cool, dry cupboard, not in the fridge, where moisture causes clumping, and write the opening date on the lid.
- For outings, carry pre-measured powder and water separately and mix at feeding time, or keep prepared bottles in an insulated bag with ice packs.
- For babies under 2 months, born prematurely or with a weakened immune system, CDC advises extra care with powder, such as using ready-to-feed formula or mixing powder with water heated to at least 158°F (70°C) and then cooling it.
How to tell if infant formula has gone bad
- A container past its use-by date; FDA advises never using formula after that date because nutrients can no longer be guaranteed.
- Cans that are dented, bulging, leaking or rusted, or a broken seal on a new container.
- Powder that is clumped, damp or discolored, or that smells sour or stale.
- Liquid formula that has separated into lumps or curds that do not mix back in, or smells off.
- None of these signs need to be present for formula to be unsafe; bacteria do not change its look or smell, so follow the time limits.
Bacteria that cause food poisoning usually do not change the look, smell or taste of food. Go by the time limits first, and the signs above second.
Infant Formula shelf life chart
| State | Fridge | Freezer | Pantry |
|---|---|---|---|
| Prepared | 24 hours | Not recommended | 2 hours |
| Once the baby starts drinking, finish within 1 hour and throw away the rest. Never save a used bottle. | |||
| Opened, powder | Not recommended | Not recommended | 1 month |
| Keep the lid tightly closed in a cool, dry place. Unopened: use by the date on the container. | |||
| Opened, ready-to-feed or concentrate | 48 hours | Not recommended | Not safe |
| Cover the container and refrigerate immediately after opening. | |||
Not safe = perishable: no more than 2 hours at room temperature (1 hour above 90°F / 32°C). Not recommended = possible, but quality suffers or it serves no purpose.
Frequently asked questions
How long is formula good for after it is mixed?
Mixed formula is good for 2 hours at room temperature, or 24 hours if it goes into the fridge right after preparation. Once your baby begins drinking from the bottle, it must be finished within 1 hour. These are CDC's time limits, and they apply to powder, concentrate and ready-to-feed alike.
Can I save a bottle my baby did not finish?
No. Throw away any formula left in the bottle after a feeding. Your baby's saliva mixes with the formula and introduces bacteria that multiply quickly, even in the fridge. To reduce waste, prepare smaller bottles and offer more if your baby is still hungry.
How long does a can of formula powder last once opened?
Most powdered formula should be used within 1 month of opening; check the label for your product. Keep it tightly covered in a cool, dry place. Discard what is left after a month, and never use formula, opened or unopened, past the use-by date.
Can you freeze infant formula?
No. Freezing is not recommended for any type of formula. It causes the fats and proteins to separate, which changes the texture and may affect how well it mixes and feeds. Store prepared formula in the fridge for up to 24 hours instead.
What if prepared formula was left out overnight?
Discard it. Formula that has been at room temperature for more than 2 hours is not safe, and no amount of reheating makes it so. It will usually look and smell normal, which is why the clock, not your senses, has to decide.
Related foods
| Food | Fridge | Freezer | Pantry |
|---|---|---|---|
| Breast Milk Fresh |
4 days | 6 months | 4 hours |
| Baby Cereal Opened |
Not recommended | Not recommended | 1 month |
| Baby Food (Jars) Opened, fruit or vegetable |
2–3 days | 1–2 months | Not safe |
| Homemade Baby Food Homemade |
1–2 days | 1–2 months | Not safe |
| Milk Opened |
1 week | 3 months | Not safe |
| Baby Food Pouches Opened |
1 day | 1–2 months | Not safe |
Reviewed 2026-09-20. Times follow published USDA FoodKeeper / FSIS, FDA and CDC storage guidance; where sources differ we use the shorter time. How we compile this data.