What happens to your body when you take expired medicine

Taking an expired medication may not kill you, but it's not what your body needs either. Find out why it is best to stay off expired medicines.

A man taking expired medicines

Key takeaways:

  • All FDA-approved medications have expiration dates, which indicate when the manufacturers consider the medication less effective or safe for use.
  • When you take expired medicine, it can affect your health by increasing the risk of antibiotic resistance, infections, and organ impairment.
  • Taking expired medication often does not cause urgent, life-threatening conditions. But if you mistakenly take expired medication, it is best to speak with a healthcare professional and ensure you take the medication to a medicine store around you for safe disposal.

From foods to drinks and every packaged edible, including drugs, consumers are encouraged not to consume anything that is out of date. This is for the sake of safety. 

In 1979, the US Food and Drug Administration (FDA) started requiring that drug makers put an expiration date on prescription and over-the-counter medicines. The expiry date is crucial for deciding whether a drug still works as intended or not.

A drug’s expiration date is usually found printed on the label or stamped on the carton or bottle. People must be careful to check for expiry dates before purchasing drugs, as using expired medicines is risky and can cause harm to their health. 

What happens when you take expired medicines?

Medicines undergo changes in their chemical makeup over time, which can cause contamination and a reduction in their effectiveness. When you take expired medications, it can cause:

  • Susceptibility to antibiotic resistance
  • Increased risk of infections
  • Allergies
  • Changes in metabolism and bodily functions

The expiry date is crucial for items that are susceptible to bacterial growth, such as medicines. Drugs can get contaminated with bacteria after expiration, leaving a consumer susceptible to infections. 

Also, taking expired drugs increases the risk of antibiotic resistance. When you take an antibiotic that has lost some of its potency (expired), the medication will not treat infections effectively. 

Because the medication cannot completely destroy the bacteria that invaded the body, they will transform, multiply, and come back in full force. When someone takes the antibiotic, the bacteria will resist its actions.

Also, expired drugs can cause health complications, giving rise to other diseases. In worst-case scenarios, they can cause harm to the kidneys and liver. There is the danger of developing allergies, having reduced immunity, or having changes in metabolism after taking expired medicines.

You can’t tell for sure whether an expired drug is still potent or not, which is why it is better to stock your medicine cabinet with fresh drugs and dispose of the expired ones.

What does the expiration date on drugs imply?

Medicines also have a shelf life, like most food items. When drugmakers print expiry dates (or "best before" dates) on medications, it means the day, month, or year printed is the cut-off date for when the medicines are considered safe for use.

This means when the stated date is reached, the medicines are no longer safe to use. It is also the final day that drug makers guarantee the full potency of the drug. 

Note that the potency of drugs starts decreasing starting from the moment they are manufactured. This means a drug’s potency doesn’t spontaneously disappear after its expiry date. 

After a drug’s expiration date, the medicine may still be potent; however, the date is only an assurance that its potency will last at least until that date. Whatever happens after that date, the manufacturer can no longer account for it.

Some medicines are still somewhat effective even 10 years after their expiration date. Placing a drug in a cool, dry place will help it retain its potency. 

It is similar to when you buy an electrical gadget, and it comes with a two-year warranty. The manufacturing company is only saying that it guarantees that, all things being equal, the gadget will work perfectly fine within the two years.

If anything goes wrong within that period, the gadget can be returned, but the manufacturer won’t be held accountable for damages after two years. 

What you should do if you mistakenly take expired medicine

Photo by National Cancer Institute on Unsplash

Don’t panic if you mistakenly take expired medication. Most times, taking expired drugs doesn’t mean you will die. It also doesn’t mean the drug will start causing bad reactions immediately.

Take the medicine back to the pharmacy for safe disposal and give a full report of why and when you took the drug. Your pharmacist will be better positioned to assess the situation and tell you what to do next. 

The best way to dispose of expired medicine

Expired medications shouldn’t be left lying around on the counter. This is because anybody, especially a child or an elderly person, can pick them up and ingest them. 

According to the Centers for Disease Control and Prevention (CDC), about 50,000 children end up in emergency wards every year because they consumed medicines while an adult isn't watching.

You shouldn’t flush expired drugs down the toilet or the drain, either. Drugs disposed of this way can make their way into the drinking water system. 

Some drugs come with specific disposal instructions; use the instructions. Otherwise, mix the medicine with dirt, seal it in a container, and throw it into the trash. 


  1. American Medical Association. (2015). Pharmaceutical Expiration Dates. Report 1 of the Council on Scientific Affairs. July 25, 2001.
  2. Centres for Disease Control and Prevention (CDC). (2020). Put your medicines up and away and out of sight.
  3. The U.S. Food and Drug Administration (FDA). (2021). Don’t be tempted to use expired medicines.