For most foods, expiration dates are about quality, not safety. With the single exception of infant formula, no federal law in the United States requires an expiration date on food products. The dates you see on groceries are set by manufacturers to indicate when a product will taste its best, and in most cases, food that’s past its printed date is still perfectly safe to eat if it’s been stored properly. But the answer gets more nuanced when you look beyond the pantry to your medicine cabinet, your makeup bag, and your refrigerator’s deli drawer.
What Food Date Labels Actually Mean
“Best if Used By,” “Sell-By,” and “Use-By” sound like they’re telling you different things, and they are, but none of them are safety dates. A “Best if Used By” date tells you when a product will be at peak flavor or quality. A “Sell-By” date is an inventory tool for the store, telling staff when to rotate stock off shelves. A “Use-By” date marks the last day the manufacturer thinks the product will be at its best. All three are the manufacturer’s best guess at quality, not a line in the sand where food becomes dangerous.
The USDA puts it plainly: if a date passes while food is in your home, the product should still be safe and wholesome as long as it’s been handled properly, until you see actual signs of spoilage. That means your yogurt doesn’t turn into a health hazard at midnight on its printed date. Use your senses: if it looks normal, smells normal, and has the right texture, it’s almost certainly fine.
The One Date That Is Legally Required
Infant formula is the only product in the U.S. that must carry a federally mandated “Use-By” date. This isn’t about taste. The FDA requires it because the formula must contain specific nutrient levels listed on its label, and those nutrients degrade over time. Using formula past its date means your baby may not be getting adequate nutrition. This is the one expiration date you should always follow without question.
Foods That Deserve Extra Caution
While most foods are fine past their dates, certain categories carry real risk, and it has less to do with the printed date than with how the food is stored and how long it’s been open. Deli meats, hot dogs, and cold cuts can harbor listeria, a bacterium that grows even at refrigerator temperatures. Once opened, these should be used or frozen within three to five days regardless of what the label says. Unpasteurized soft cheeses, smoked seafood that isn’t shelf-stable, and raw sprouts fall into the same higher-risk category.
The danger with these foods isn’t that they magically spoil on a specific date. It’s that the bacteria responsible for serious illness don’t always produce visible signs. A package of deli turkey can look and smell perfectly fine while carrying enough listeria to make someone seriously ill, especially pregnant women, older adults, and people with weakened immune systems.
Canned Goods Can Last for Years
Commercially canned foods are some of the longest-lasting items in your kitchen. High-acid foods like tomatoes and fruits hold their best quality for about 18 months. Low-acid foods like canned vegetables and meat can stay good for two to five years. The key is storage: keep cans in a cool, dry place, away from temperature extremes.
The real warning signs for canned goods have nothing to do with a date. Never use food from a can that is leaking, bulging, badly dented, or that spurts liquid when you open it. A foul smell when you crack the lid is another clear signal. These are indicators of possible botulism contamination, which is rare but genuinely dangerous. A can that’s past its printed date but looks and smells fine after proper storage is safe to eat, though the flavor and texture may have declined.
Medications Are a Different Story
Drug expiration dates work differently from food dates. Pharmaceutical companies are required to test their products and guarantee full potency up to the printed date. After that point, there’s no guarantee the medication will work as intended. For most over-the-counter pain relievers or allergy pills, a slightly reduced potency is unlikely to cause harm. But for certain medications, even a small drop in effectiveness can be serious.
Liquid antibiotics, for instance, degrade faster than tablets and can lose enough potency to fail at treating an infection. A sub-potent antibiotic doesn’t just leave you sick longer; it can contribute to antibiotic resistance. Insulin and heart medications like nitroglycerin are other categories where potency loss isn’t just inconvenient but potentially life-threatening.
There is one notable case where an expired drug actually became toxic rather than simply weaker. Expired tetracycline, an older antibiotic, has been linked to kidney failure in a small number of patients who took it after its expiration date. Those patients developed nausea, vomiting, and metabolic acidosis within two to eight days. Researchers attribute the toxicity to chemical breakdown products that form as the drug degrades. No recent cases have been reported, partly because modern formulations are more stable, but the episode illustrates why medications deserve more respect than a carton of milk when it comes to expiration.
How Storage Conditions Change Everything
An expiration date assumes you’ve stored the product under reasonable conditions. Heat, humidity, and light all accelerate degradation, whether you’re talking about food, drugs, or cosmetics. Research on pharmaceutical compounds shows that at low humidity levels, many drugs resist breakdown well. But once relative humidity climbs above about 50%, degradation rates increase significantly and more breakdown products form.
This is why storing medications in your bathroom, where steam from showers creates a humid environment, is one of the worst choices you can make. A cool, dry bedroom closet is far better. The same principle applies to the supplements and vitamins people often keep on kitchen windowsills in direct sunlight. A product that might have lasted well past its expiration date under ideal conditions can lose potency months early if it’s been baking in heat or absorbing moisture.
Cosmetics and the Open-Jar Symbol
Cosmetics occupy a middle ground between food and medication. Most products carry a small open-jar icon on their packaging with a number followed by “M,” indicating how many months the product is good for after you first open it. A “12M” symbol means 12 months of use after opening.
For most cosmetics, using a product past this window means reduced performance: a foundation that separates, a moisturizer that smells off. But eye products are a genuine health concern. Mascara has high water content that makes it an ideal breeding ground for bacteria, and it’s applied directly next to mucous membranes. Research has found significant microbial contamination in mascara just three months after opening. Eye shadow actually shows the highest degree of contamination among expired cosmetics in lab testing. The consequences aren’t trivial: expired eye cosmetics have been linked to eye infections, and in severe cases, urinary and respiratory tract infections and even meningitis from microbial contamination.
If you’re going to pay attention to any cosmetic expiration timeline, make it your eye products. Three months for mascara is a good rule, and if you’ve had an eye infection, replace everything that touched the area immediately.
COVID Tests and Extended Dates
If you have at-home COVID-19 tests sitting in a drawer, check the FDA’s website before throwing them away. The FDA has extended the expiration dates on many authorized home tests, sometimes by months beyond what’s printed on the box. The agency maintains an updated table listing each test by manufacturer and whether its date has been extended. A test that looks expired based on its packaging may still be valid according to the FDA’s revised timeline.
A Practical Way to Think About Dates
The simplest framework: food dates are suggestions, infant formula dates are mandatory, medication dates matter more than you think, and cosmetic dates matter most for anything touching your eyes. For everything in your pantry and fridge, trust your senses over the label. For medications, err on the side of replacing them, especially liquids, antibiotics, and anything you depend on for a serious condition. And regardless of the product, how you store it often matters more than what date is stamped on it.