An antihistamine, Benadryl (diphenhydramine) is used for relieving symptoms associated with hay fever, allergy, and the common cold. Symptoms typically include itching, rash, watery eyes, itchy throat/nose/eyes, runny nose, cough, and sneezing.

Benadryl also finds use in the prevention and treatment of motion-sickness related nausea, vomiting, as well as dizziness.

Expiration Date

Drug manufacturers have been mandated by a federal law passed in 1979 to provide expiration dates for their products. This date is the date until which the manufacturer guarantees the efficacy and potency of the drug.

Drug expiration dates came into existence after a study conducted by the US FDA at the request of the US military. The US military had to, every few years, toss out a large stockpile of medications and wanted to find a solution to this.

Studies conducted by the US FDA revealed that almost 90% of about 100 drugs (both OTC and prescription) were safe to use up to 15 years after their expiry.

So, Can We Still Use Expired Benadryl?

Yes, you can. A drug past its expiry does not mean it is unsafe to use.

According to medical authorities, a medication past its expiration date doesn't indicate a lack of efficacy or potency or safety. One can safely use an expired medicine, a rare exception being tetracycline.

It is a given fact that the effectiveness of medication decreases over a period, but much of its potency remains even 10 to 15 years after its expiry.

Excluding insulin, nitroglycerin, and liquid antibiotics, most of the medications are as longlasting as the medications tested by the US military.

Placing a drug in its original container, in a cool place (ideally a refrigerator), away from humidity, direct sunlight, or freezing temperature helps the medication to retain its potency for several years.