Quick answer
Yes. Never use infant formula after its printed use-by date. Opened powder also has a label-specific after-opening limit; whichever comes first applies. Mixed bottles have much shorter limits. This guide covers routine commercial powdered infant formula, not specialist prescribed feeds, toddler drinks or ordinary powdered milk. FDA formula advice
The tin and bottle have different deadlines
| What you have | What to follow |
|---|---|
| Unopened powder | Package storage instructions and use-by date. |
| Opened dry powder | Label's after-opening limit and use-by date, whichever comes first. |
| Freshly prepared bottle, not yet used | Use within two hours of preparation. If saving for later, refrigerate immediately and use within 24 hours of preparation. |
| Feeding has begun | Use within one hour of starting, without exceeding an earlier applicable deadline. Discard the remainder after feeding. |
The bottle limits follow CDC storage guidance. Keep the fridge at 40°F (4°C) or below; a warm fridge does not qualify. Do not substitute these rules for instructions on liquid concentrate or ready-to-feed formula. FDA refrigerator guidance
Read the opening instruction before the first scoop
Enfamil's US guide gives 30 days after opening or the expiration date, whichever is sooner. That maker's example is not permission to assign 30 days to every formula. Keep the actual container and follow its wording. Enfamil storage guide
Write the opening date on the lid. Store powder tightly closed in a cool, dry indoor place, rather than in the fridge. FDA says a washed scoop must be completely air-dried before reuse. Keep water out of the powder and retain the package's batch and expiry information.
The use-by date is more than a flavor preference. FDA explains that it reflects evidence about nutrient levels and acceptable quality when the formula is stored as directed. Do not stretch it because the powder looks normal. FDA formula questions and answers
Starting a feed does not restart the clock
If you mix a room-temperature bottle at 10 a.m. and start feeding at 11:30 a.m., its two-hour preparation limit arrives at noon. Starting the feed does not extend it to 12:30. If feeding ends sooner, discard what remains then.
For advance preparation, refrigerate promptly and mark the preparation time. Do not deliberately leave a bottle out for two hours before chilling it. Follow your product's water quantity, scoop and mixing instructions; another tin's recipe is not interchangeable.
FAQs
Can I save a half-used bottle?
No. Discard formula remaining after feeding rather than refrigerating it for the next feed. Saliva can introduce bacteria; use a clean, sanitized bottle next time. CDC Cronobacter prevention
Does refrigeration extend opened powder's life?
No. Store dry powder as its label directs, cool and dry with the lid closed. Chilling powder does not add days to its opening limit or printed use-by date.
Is powder sterile before its date?
No. Babies younger than two months, those born prematurely and those with weakened immune systems need extra preparation precautions. Follow CDC's linked guidance and your clinician's advice; this expiry guide is not a complete bottle-making procedure. Check current FDA safety notices and recalls too.
Sources
Sources and draft evidence reviewed October 31, 2026. Manufacturer advice applies to the named product; follow stricter local guidance and your package. How we research our guides.