If you’re treating a wound that’s infected—it’s red, painful, and oozing pus—or if the wound still looks dirty after washing it, our experts say it’s fine to use Neosporin topical ointment within a year after it’s expired. That’s because some research suggests many medicines are still effective even several years after the expiration date. The date you see stamped on your medicine is the time until which the drug manufacturer can guarantee its maximum safety and potency based on product testing.

“To assure that medicines stay effective after their expiration dates, don’t store them in bathroom medicine cabinet,” suggests Marvin Lipman, chief medical consultant, Consumer Reports. “Heat and humidity accelerate how fast a drug deteriorates, so store drugs in a cool, dry place and well out of the reach of children.”

 

But there are situations when you shouldn’t use antibiotics creams at all, which have nothing to do with whether the drug is expired or not. That’s because overusing those creams, like overusing any antibiotic, and others like it—Bacitracin Plus, Curad, Mycitracin, Polysporin, and generic versions, for example—can contribute to the spread of resistant bacteria, making these drugs less likely to work when you really need them. A 2011 study found a link between using Neosporin and other over-the-counter antibiotic ointments and the spread of a resistant MRSA (methicillin-resistant staphylococcus aureus) strain of bacteria called USA300, which is now being found more commonly.

Instead of using an antibiotic ointment, a safer way to treat a minor cut, scrape, or burn is to wash it with soap and warm water to clear out any visible dirt. Then cover it with a non-stick bandage and keep an eye on it. Your wound should heal on its own in 7 to 10 days; if it doesn’t, see your doctor.

Another reason to go easy on topical antibiotics: the risk of skin reactions. Both bacitracin and neomycin carry a small risk of skin irritation and allergic reactions, such as contact dermatitis. The risk is slightly less for bacitracin.

Good to know for all your medication: Cases where you should stick closely to the expiration date include certain liquid medications such as nitroglycerin, insulin, and epinephrine, and especially the antibiotic tetracycline—which, past it expiration date can become toxic and cause kidney problems—should not be used past the expiration date.

Still to be on the safe side and be sure you’re getting a medicine’s full potency, experts advise replacing medicines that have expired years ago with a new supply. Although take-back programs are a good way to get rid of expired medications, it’s OK to toss your old tube of Neosporin in the household garbage. But you’ll want to be sure to take precautions so that children or pets don’t get their hands (or paws) on it, says Barbara Young, Pharm.D., editor of consumer-medication information for the American Society of Health-System Pharmacists. When in doubt, ask your pharmacist about proper disposal.  

These materials were made possible by a grant from the state Attorney General Consumer and Prescriber Education Grant Program, which is funded by a multistate settlement of consumer fraud claims regarding the marketing of the prescription drug Neurontin (gabapentin).