Unopened baby formula lasts until the “use by” date printed on the container, which is typically 12 to 18 months from the date of manufacture depending on the brand and type. There is no universal shelf life in weeks or months because each manufacturer sets its own date based on testing. That printed date is the only reliable guide.
What the Use-By Date Actually Means
The FDA requires every container of infant formula sold in the United States to carry a “use by” date. This isn’t a suggestion or a rough estimate. The manufacturer must demonstrate through testing that the formula, until that date, will contain no less than the amount of every nutrient listed on the label and will still be usable (flowing properly through a bottle nipple, for example). After that date, nutrient levels may have dropped below what your baby needs, and the manufacturer no longer guarantees quality or safety.
This makes infant formula different from most other packaged foods. “Best by” dates on adult foods are often about peak quality, and the food may still be fine for weeks afterward. Formula use-by dates carry more weight because infants depend on formula as their sole or primary source of nutrition. A decline in vitamin or mineral content matters far more when the food is everything your baby eats.
Powder, Liquid Concentrate, and Ready-to-Feed
All three types of formula follow the same rule: use by the printed date. However, the timeline from manufacturing to that date varies by format. Powdered formula generally has the longest shelf life because removing moisture slows degradation. Liquid concentrate and ready-to-feed formulas contain water, which shortens their viable window. You’ll typically see a closer expiration date on liquid products compared to powder bought around the same time.
Regardless of type, once a container is opened, the shelf life changes dramatically. Powdered formula is generally good for about 30 days after opening. Liquid concentrate and ready-to-feed containers should be refrigerated and used within 48 hours of opening. But as long as the container stays sealed, the printed date is what matters.
How to Store Unopened Formula
Where you keep unopened formula affects whether it actually stays good until the use-by date. The CDC recommends storing sealed containers in a cool, dry, indoor location. A kitchen pantry or cabinet away from direct sunlight works well. Avoid storing formula in your car, garage, or anywhere exposed to temperature swings or humidity. Heat accelerates nutrient breakdown, and moisture can compromise powdered formula even through packaging over time.
There’s no need to refrigerate unopened formula. Room temperature is fine as long as the environment stays reasonably stable. The use-by date assumes normal household storage conditions, so keeping formula in an overheated space could mean the contents degrade faster than the label accounts for.
When to Throw It Out (Even If It’s Unopened)
The expiration date isn’t the only reason to discard sealed formula. Physical damage to the container can make formula unsafe regardless of the date. Do not buy or use any formula in a container that is dented, bulging, leaking, or rusty. A bulging can suggests possible bacterial contamination. A dent near the seam could compromise the seal, allowing air or moisture inside. Rust weakens metal and can introduce contaminants.
Even without visible damage, check formula before preparing it. An unusual smell or color change after opening a container that’s within its date could mean the formula has gone bad. This is rare with properly stored, undamaged containers, but it’s worth a quick check every time. If anything seems off, discard it.
Can You Use Formula Past the Use-By Date?
No. The FDA is clear that formula should not be used after its printed date. Unlike many foods where expiration is a quality guideline, formula past its date poses two distinct problems. First, the nutrient content may no longer match the label, meaning your baby could be getting less of critical vitamins and minerals than you think. Second, the physical and chemical stability of the product is no longer guaranteed, which raises the possibility of spoilage that may not be immediately obvious.
If you find a can in the back of the pantry that’s a month or two past the date, it’s not worth the risk. Formula is too central to an infant’s diet to gamble on diminished nutritional value, even if the powder looks and smells normal.
Buying and Rotating Your Supply
When stocking up, check the use-by date before purchasing. Containers at the front of store shelves sometimes have earlier dates than those behind them. If you buy in bulk, rotate your stock so older containers get used first. Write the purchase date on each can with a marker if it helps you keep track.
If you’re buying formula online or from a discount retailer, pay extra attention to the date and packaging condition on arrival. Formula that shipped in extreme heat or arrived with damaged packaging should be returned. The savings aren’t worth the uncertainty about whether storage conditions were maintained during transit.