Food, cosmetics and household cleaning products are just a few of the many everyday items that carry a “best by” date. Most prescription and over-the-counter medications are also assigned a day of expiration, but it's not nearly as easy to tell when drugs go “bad.” This leaves many consumers confused as to the purpose of these seemingly arbitrary dates.

We’ve all held onto a leftover prescription just in case we can use it later on and save a trip to the doctor, and most people don’t go through big bottles or packs of OTC meds before they expire. But the question remains: do drugs really expire? Are expiration dates hard and fast rules or simply guidelines? What happens when a drug goes bad?

Why Expiration Dates Exist

Mandated by the Food and Drug Administration (FDA) in the late 1970s, prescription expiration dates are initially set by drug manufacturers. Based on when the medication was dispensed, a pharmacy may also assign their own expiration date that precedes the manufacturer's. Most prescriptions carry an expiration date of about a year from when a pharmacist opened the original package or bottle.

The idea of a pill or tablet going bad might seem doubtful, but it's important to pay attention to these dates. Expired medicines can make you sick. Not because they are spoiled, per se, but because they no longer work the way they should. An expiration date simply stipulates the date through which a manufacturer can guarantee a medication’s full potency and safety.

“Once enough time has passed, most drugs begin to lose potency,” cautions Dr. Kathryn A. Boling, a primary care physician with Mercy Medical Center in Lutherville, Maryland. Even though recent studies indicate that certain drugs retain their effectiveness beyond their official expiration date, Dr. Boling says that people who take a drug after it has expired may end up receiving an improper dosage or experience adverse effects. For example, some drugs, such as the antibiotic tetracycline, not only lose their effectiveness but can also become toxic beyond a certain date.

The Importance of Proper Storage

Ensuring the optimal effectiveness of prescription medications goes beyond just monitoring dates. “Storing drugs incorrectly can cause them to become ineffective even before the expiration date has passed,” Dr. Boling warns. “Most people keep medications in their bathroom medicine cabinet, which, when you think about it, is not the best place in the world because it probably encounters more fluctuations in humidity and temperature than anyplace else in the home. Exposure to these elements may cause the drug to lose even more potency.”

Cool, dry and dark conditions are ideal for storing most medications. If the bottle comes with a cotton plug, remove it to prevent moisture from being trapped inside the container. Be on the lookout for changes in color and texture. This applies to liquid medications and ointments as well. These basic signs indicate that a medication has gone bad and should be replaced, regardless of the date on the bottle.

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For medication-specific storage instructions, consult your pharmacist or the insert that came with the medication.

How to Properly Dispose of Medications

Leaving old, expired or unused medications in the house can pose a serious health hazard, especially for older adults, younger children and pets. Generally, there are three different options for disposing of medications properly.

  • Find a take-back program. There are both periodical National Prescription Drug Take-Back Events held throughout the year and permanent collection sites where consumers can take their medications for responsible disposal. Ask your local pharmacy, hospital or law enforcement agency if they participate in one of the these take-back programs. Choosing to drop off unneeded medications at a permanent site or use an official mail-in program is the safest and most environmentally friendly method of disposal.
  • Trash it. Prescriptions that do not come with specific disposal instructions can be safely placed in the household garbage by following a few simple steps. First, without crushing individual pills or tablets, mix the medication with an inedible material, such as soil, kitty litter or used coffee grounds, in a sealed container or bag. Throw the contained mixture into the trash, and be sure to cross out all personal information on the original medication container before disposing of it as well.
  • Flush it. A select few medications can be especially harmful (even fatal) and therefore come with instructions for immediate disposal once they are no longer needed. The recommended version of rapid disposal is to flush these drugs down the toilet. The FDA has compiled a list of these prescriptions, which you can find here: Medicines Recommended for Disposal by Flushing. Unfortunately, flushing medications increases the likelihood that these chemicals may end up in the water system, but it is crucial to quickly discard dangerous drugs, such as fentanyl patches, to reduce the household risk of accidental ingestion or misuse.