Does Cephalexin expire? 

Does Cephalexin expire? 

Yes, Cephalexin does expire. If we talk about solid oral dosage form, the drug may have an expiry date of about 3 to 6 years, depending on the preservatives and excipients used by different pharmaceutical manufacturers. 

If we talk about liquid oral dosage form, it has a short expiry date. This is because oral liquid dosage forms are more susceptible to microbial contamination because of their physical instability. This antibiotic should not be consumed after it has expired. 

It does not necessarily cause toxicity if consumed after it expires, but it may cause therapeutic failure, which is an entire problem on its own, especially when you’re dealing with an active bacterial infection. This is why it is best to avoid expired medication (1).

What are the dangers associated with consuming expired Cephalexin? 

Cephalexin is an antibiotic and it needs to be effective enough to help you fight against your active bacterial infection. 

If you have consumed an expired medication or you continue to do so, there are changes in some of the complications that may occur in some people, while others may get away with it. Some of the possible complications include:

  • Therapeutic failure 
  • Antibiotic resistance 
  • An inevitable allergic reaction 
  • Possible damage to the liver and kidneys 

Therapeutic failure 

Therapeutic failure is the biggest concern when it comes to using expired Cephalexin. If your antibiotic is not active enough, it will not hinder the growth of infectious bacteria. This will lead to no changes in your condition and the bacteria will continue to thrive. 

This can make your infection worse and your symptoms may become more disturbing. This is why it is extremely important to use safe and effective antibiotics to help kill the infection-causing bacteria. 

Antibiotic resistance 

Antibiotic resistance is another problem that can make you say goodbye to Cephalexin for your entire life. If you continue to take Cephalexin in its effective form, the bacteria may become resistant to the entire chemical structure of the drug.

Experts believe that bacteria evolve to create a stubborn type of resistance against such an antibiotic and no matter how effective the antibiotic you use the next time, it won’t work. Your doctor may need to switch you to another antibiotic.

An inevitable allergic reaction

Another important risk associated with the use of expired Cephalexin is an inevitable allergic reaction. As this antibiotic can become ineffective after its expiry date, the inactivated drug moiety may cause an allergic reaction in your body. 

Some of the common symptoms associated with such an allergic reaction include:

  • Redness of skin 
  • Itching 
  • Burning sensation 
  • Blue-purple patches 
  • Tightness of chest or chest pain
  • Inability to breathe 
  • Wheezing 
  • Hoarseness 
  • Swelling of lips, tongue, eyes, throat 

Possible damage to the liver and kidneys 

An expired Cephalexin may end up affecting your liver and kidneys. These two organs are primarily involved in the processes carried out by your body when you take Cephalexin or any other medication. 

Not only this but the liver and kidneys help to eliminate the drug from your body as well, as the liver metabolises the drug and the kidney removes it from your body via urine. If the drug affects these two organs, it may become accumulated in the body and cause further damage.

What to do if you have taken an expired Cephalexin tablet? 

If you have accidentally consumed an expired Cephalexin tablet, you may not suffer from any significant side effects. However, it is not recommended to take an expired antibiotic, but these meds usually stay fine after 4 to 6 years of their expiry date. 

So, if you feel nothing at all after taking an expired Cephalexin, there is nothing to worry about. If you do feel anything, immediately call your medical emergency helpline and seek professional help. 

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U.S. Food and Drug Administration. Don’t Be Tempted to Use Expired Medicines [Internet]. Silver Spring (MD): U.S. Food and Drug Administration; 2021 [cited 2022 Sep 26]. Available from: