Do drugs always degrade after they have passed their expiration date?

Do drugs always degrade after they have passed their expiration date?

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I have been wondering for some time whether several drugs really have an expiration date.

Let's narrow the scope and think about only "common" drugs, e.g NSAIDs, antibiotics etc. For example, would antibiotics in the pills get deactivated or decomposed?

Drugs do not have to degrade after their expiration date and passing the expiration date has more than one possible meaning.

First of all chemical compounds vary in their susceptibility to breakdown over time. If they are kept away from oxygen, high temperatures (or kept in very low temperatures), and they are of a robust chemical nature, they might be stored for much longer than their expiration date and remain just as strong.

Over time, pharma compounds will chemically break down and lose their potency. In many cases, you will find that they simply don't do anything when you take them. This link cites a study that many drugs can retain their potency 15 years after they are made.

There are important exceptions. Two examples are tetracycline and acetaminophen (tylenol) whose breakdown products can increase the tendency for these drugs to induce liver damage.

Why do medicines have expiry dates?

Medicines have expiry dates so you know when to use them by. After the expiry date medicines may not be safe or as effective.

You should not take medicines after their expiry date. If you've had a medicine for a while, check the expiry date before using it.

You should also make sure that you've stored the medicine properly, as described on the packaging or leaflet.

If your medicine looks, tastes or smells different to when you first got it, even if it's within the expiry date, take it to your pharmacist for advice.

Does viagra have an expiration date?

Like all medications , yes it has an expiration date.

As a drug sits around, it begins to degrade, thereby losing its effectiveness. The drug does not all degrade at the same time but rather over a period of time. The potency begins to decrease. The result is unpredictable results. The manufacturer puts an expiration date so that they can guarantee its effectiveness and potency through that date.

Take care an have a good weekend.

Note: There is only 1 manufacture of the TRUE Viagra, and that is Pfizer Pharmaceuticals.

Expiration dates can also indicate if your medicine, particularly eye drops or injected medication, is still sterile

"The second thing is, with insulin and with most injectables or eye drops, we worry about what's called sterility," Hartzell said. "Has that solution been infected or contaminated with another pathogen? Or a virus or a fungus or something? … [An expiration date] means it's not been contaminated up until that date. They can prove that what they've done in manufacturing will make sure that it's safe up until that date."

Hartzell said he usually recommends for patients to just throw away any expired medicines because of that.

"My thing that I've always told [patients] is, I can tell you from what I know that this medication will work up until that date. I can also tell you that it's safe and we're not going to have a problem up until that date because it's not contaminated," he said.

"After that date, I can't tell you anything. So it's kind of like buyer beware at that point. But if you're having an anaphylactic reaction and you have nothing else, [an expired epi-pen is] better than nothing … But I'm very leery on how I tell that to a consumer."

Types of Contacts & Their Expiration

With an estimated 45 million people in the U.S. who wear contact lenses, it is no surprise that many different types of contact lenses have been developed. There are a few main types of contact lenses, explains the FDA.

  • Soft contacts. Available in both extended wear and disposable forms, these lenses are made of soft and flexible plastics so oxygen can pass through to the cornea. They are relatively easy to adjust to and more comfortable than rigid lenses.
  • Rigid gas permeable (RGP) lenses. Although they are more rigid than soft lenses, RGP lenses are more reliable and more resistant to the buildup of deposits. They typically produce clearer vision.
  • Extended wear contacts. Designed for overnight or continuous wear, these lenses can be worn from one to six nights or for up to one month during the day. They are typically soft contact lenses, though there are a few RGP lenses approved for overnight wear.
  • Disposable contacts. As defined by the FDA, disposable contacts are meant to be used once and then discarded. A brand new pair of lenses is meant to be worn each day.
  • Replacement schedule contacts. Replacement schedule lenses are designed to be worn for a set period of time, such as one day, two weeks, or one month. The lenses may be worn continuously for the prescribed amount of time and must be then thrown away.
  • Decorative contacts. All the same rules and regulations of contact lens care and expiration apply to decorative lenses, worn for cosmetic or costume purposes. Decorative lenses should still be obtained through a prescription, whether you need them for vision correction or not.

5 Drugs That Should Never Be Used Past Their Expiration Date

Certain medications have a narrow therapeutic index and little decreases in the pharmacological activity can result in serious consequences for patients. Observing the expiration date is obligatory for the following medications:

  • Anticonvulsants - narrow therapeutic index
  • Dilantin, phenobarbital - very quickly lose potency
  • Nitroglycerin - very quickly lose potency
  • Warfarin - narrow therapeutic index
  • Procan SR (sustained release procainamide) - powerful antiarrhythmic agent
  • Theophylline - very quickly lose potency
  • Digoxin - narrow therapeutic index
  • Thyroid hormone preparations
  • Paraldehyde
  • Oral contraceptives
  • Epinephrine - very quickly lose potency
  • Insulin - very quickly lose potency
  • Eye drops - eyes are particularly sensitive to any bacteria that might grow in a solution once a preservative degrades.
  • Long-expired antibiotics (e.g. amoxicillin, azithromycin, cephalexin, doxycycline) can contribute to increased antibiotic resistance and treatment failure [5] .

Huge amounts of medication thrown out

They tested five types of drug, all one to four years past expiration, and compared these to fresh samples of the same medications to see if the expired versions were chemically stable and retained their active ingredient.

  • Atropine, which is used to treat certain types of pesticide or nerve agent poisonings.
  • Nifedipine, a calcium channel blocker that relaxes the heart and blood vessels in cases of high blood pressure and chest pain.
  • Fucloxacillin, an antibiotic in the penicillin family.
  • Bendroflumethiazide, a diuretic used to treat hypertension.
  • Naproxen, a nonsteroidal anti-inflammatory (NSAID) painkiller.

Researchers found that all of the tested drugs were stable, and would, theoretically, have still been effective. The researchers caution that their results are limited by the fact that they did not know the exact temperature exposures the returned drugs had experienced.

"Even in western facilities, the true longevity of medication is a relevant question," Browne said. "There are huge amounts of medication that are thrown away due to them reaching their expiry date, and this is a cost that is passed on to the public through taxes, insurance or other medical bills."

Expiration dates and stability data would be useful to discuss in terms of national stockpiles of antidotes for bioterrorism and chemical warfare, noted Dr. Patil Armenian of the University of California, San Francisco at Fresno, who wasn't involved in the study.

Armenian has studied the shelf life of naloxone, a rescue medicine for opioid overdoses, and found that it's not as stable when exposed to heat. If left in a car in hot summers in Arizona, California or other hot spots, some drugs could degrade more quickly, she noted.

"For everyday use, consumers should continue to adhere to recommended expiry dates," Browne said. "But this opens the door to further research of how expiry dates should reflect the true longevity of drugs kept in real-life environmental conditions."

Of course, all foods look older quicker if it they are not stored properly. But remember, like a lot of other condiments, it usually has a best by date and not a use by date or expiration date. Because of this distinction, you may safely use it to compliment your favorite meals, snacks or drinks even after the best before date has lapsed.

Practicing proper hygiene and food safety techniques will help prevent foodborne illness.

That's right, honey is one food that never spoils! Although the look of your product will change somewhat over time, it will never actually spoil. Honey will begin to look yellow and cloudy instead of golden and clear and will get thicker and grainy over time, eventually looking white and hard. But, it is still good. In this form, the honey may have started the process of crystallization. Crystallized honey is where some of the glucose content in the honey spontaneously crystallized. In this state, it can also be called "candied" or "granulated" but is still safe to eat. If you would like to fix the color of your honey or turn crystallized honey into its soft liquid form, see the section below on how to fix honey.

There are, of course, certain health risks associated with spoiled foods so always remember to practice food safety and enjoy your foods before their shelf life has expired!

Generally speaking, it is not recommended to take expired drugs (past the manufacturer expiration date).

The main concern is that they may not have the same effectiveness or potency they had when they were in date.

You just don't know whether or not the medication is still good and there really isn't a perfect way to tell. Having effective medication is extremely important for certain situations that may be life-threatening.

If you needed Benadryl to stem an allergic reaction, it would prudent to always have a bottle that is in date so you know it will give you an effective dose.

Drug Expiration Dates

The official definition of the manufacturer's expiration date is as follows:

"The date beyond which ideally stored medications in the unopened manufacturer's storage container or in most circumstances, the opened and intact manufacturer's storage container, should not be used."

United States Pharmacopeia (USP)

The manufacturer's expiration date is usually expressed as the month and year, or as a day, month, and year. The manufacturer of the drug determines the day the drug will expire based on the clinical trials it does for that drug.

It almost never means that the drug goes "bad" after the date. The date on the bottle is the date up to which the manufacturer knows the drug still maintains its potency and safety as advertised. Simple as that!

In reality, a drug may be good for a long time after the listed expiration date, but there just haven't been any studies on it to know one way or the other.

Do Drugs Go Bad?

Most drugs don't actually go "bad" but they may have lost potency and thus will not have the desired effect as mentioned above.

Now, manufacturers typically use 2- to 3-year expiration dates because it is convenient. They don't need to perform longer stability tests. and the short dating assures the purchase of new drugs. [1]

They might not exactly know in 2-3 years the drug is longer good, but they will put that on the bottle so they do not have to perform stability tests for longer periods of time.

Harm from taking expired drugs is extremely rare has only been linked to degraded tetracycline. There are rare reports of kidney damage in patients who took outdated tetracycline in the 1960s. [2]

Also, some degraded drugs do have an altered taste or smell. For example, aspirin is left out too long, does degrade and has a foul odor associated with it when it is no longer good. [3]

Re-Packaged Drugs

In terms of drugs that have been repackaged (e.g. pharmacy dispensing into a prescription vial), a major regulatory body for pharmacy in the United States, known as USP, recommends no more than a one-year expiration date for drugs that are not in their original, unopened package. [4]

This is because re-packaged drugs (not in original bottle) don't have the light protection and the moisture-absorbing qualities as pharmacy prescription vials do. All in all, your Benadryl (diphenhydramine) probably isn't bad or harmful, just not as effective.

Expired Benadryl

To sum everything up, Benadryl past its expiration date likely won't harm you (from the drug itself). There have been no reports of expired Benadryl causing harm and there is no indication that it breaks down into harmful components.

However, and this is an important point, it may not be as effective as it once was.

If you are relying on Benadryl to help reduce the symptoms of an allergic reaction, it would be prudent to have an 'in-date' product so you know it will have its stated potency and work as intended.


Allen LV, Bassani GS, Elder EJ, Parr AF. “Strength and Stability Testing for Compounded Preparation.” USP Compounding Expert Committee. Published January 13, 2014. Available at: Accessed December 20, 2017.

Auerbach, Paul S., et al. Auerbachs wilderness medicine. Elsevier, 2017.

Becker G, Fritz HE, Mennicke W, et al. Temperaturbelastung von Arzneimittelen an Bord. Pharm Ztg 1983128:794-797.

Cantrell FL, Suchard JR, Wu A, Gerona RR. Stability of active ingredients in long-expired prescription medications. Arch Intern Med. 2012172(21):1685–1687.

Cantrell FL, Cantrell P, Wen A, Gerona R. Epinephrine concentrations in EpiPens after the expiration date. Ann Intern Med. 2017166:918–919.

Cohen LP. Many medicines are Potent Years Past Expiration Dates. The Wall Street Journal. Published March 28, 2000. Accessed December 15, 2017.

Church WH, Hu SS, Henry AJ. Thermal degradation of injectable epinephrine. Am J Emerg Med 199412:306.

Gill MA, Kislik AZ, Gore L, Chanda A. Stability of advanced life support drugs in the field. Am J Health Syst Pharm 200416:597.

Government Publishing Office. “Electronic Code of Federal Regulations. Title 21: Food and Drugs, Part 211, Subpart I – Laboratory Controls.” Available at: Accessed December 17, 2017.

George W. Frimpter, Alphonse E. Timpanelli, William J. Eisenmenger, Howard S. Stein, Leonard I. Ehrlich. Reversible “Fanconi Syndrome” Caused by Degraded Tetracycline. JAMA 1963184(2):111–113.

Harvard Health Publishing. “Drug Expiration Dates – Do They Mean Anything?” Published August 13, 2017. Accessed December 13, 2017.

Hogerzeil HV, Battersby A, Srdanovic V, Stjernstrom NE. Stability of essential drugs during shipment to the tropics. BMJ 1992304:210-212.

International Conference on Harmonization: “Guidance for Industry Q1A(R2) Stability Testing of New Drug Substances and Products.” Available at: Accessed December 17, 2017.

Kramer TAM. “Do Medications Really Expire?” Medscape General Medicine. 2003. Accessed December 13, 2017. Retrieved from:

Küpper TEAH, Bettina S, Burkhard R, et al. Drugs and drug administration in extreme environments. J Travel Med 200613:35–47.

Lyon RC, Taylor JS, Porter DA, et al. Stability profiles of drug products extended beyond labeled expiration dates. J Pharm Sci 200695:1549–1560.

Madden JF, O’Connor RE, Evans J. The range of medication storage temperatures in aeromedical emergency medical services. Prehosp Emerg Care 19991:27.

Ogunshe A, Adinmonyema P. Evaluation of bacteriostatic potency of expired oral paediatric antibiotics and implications on infant health. Pan Afr Med J. 201419:378.

Rawas-Qalaji M, Simons ER, Collins D, Simons KJ. Long-term stability of epinephrine dispensed in unsealed syringes for the first-aid treatment of anaphylaxis. Ann Allergy Asthma Immunol 2009102:500.

Rudland SV, Jacobs AG. Visiting bags: a labile thermal environment. BMJ 1994308:954-956.

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