Does Cephalexin raise blood sugar? (+3 tips)

In this article, we will explore whether Cephalexin can cause elevated blood sugar levels or not, what is the potential link between Cephalexin and elevated blood sugar levels, what are the side effects of taking Cephalexin and what to do if Cephalexin causes elevated sugar levels in the blood.

Does Cephalexin raise blood sugar?

No, Cephalexin itself does not cause elevated blood sugar levels in patients who are not diabetic. However, it can indirectly affect your blood sugar levels and if you are already diabetic or taking hypoglycemic medications, then you need to monitor your conditions while taking Cephalexin.

Cephalexin is a cephalosporin antibiotic that works by inhibiting cell wall synthesis in bacteria or certain other microbes. It stops the growth of bacteria to prevent the further proliferation of infection. It is a beta-lactam antibiotic belonging to the first generation. It is usually prescribed to treat certain bacterial infections and sinus infections (1).

If you are taking Cephalexin and experience elevated sugar levels then you need to consult your doctor for this effect as it can be dangerous if you are a diabetic patient or have any other cardiovascular issue.

What is the link between Cephalexin and blood sugar levels?

The exact link between Cephalexin and blood sugar is not yet detemined by the researchers. Currently, there is limited evidence to support a consistently elevated blood sugar level after taking Cephalexin. However, a temporary fluctuation may occur.

Cephalexin is a Cephalosporin and some cephalosporins are known to inhibit the enzyme that causes the breakdown of metformin. This may cause a higher concentration of Metformin in blood, a diabetic medication. This may lead to a long-term effect on the blood sugar levels. However, this can cause hypoglycemia and not elevated sugar levels (2).

What side effects are common with Cephalexin use?

Cephalexin can be linked to a list of side effects. These may include the following (3).

Common side effects Uncommon side effects Rare side effects
  • Nausea
  • Vomiting
  • Diarrhea
  • Stomach pain
  • Headache
  • Dizziness
  • Allergic reaction
  • Yeast infection
Kidney issue, however, rarely affects kidney function

Not all patients taking Cephalexin might experience all these side effects. Some might not even experience a single one. This highly depends upon certain factors including individual sensitivity.

What to do if Cephalexin causes an elevated blood sugar level?

If you are taking Cephalexin and experience an elevated blood sugar level then you need to consult your healthcare provider. They will have to perform all the necessary tests to determine the exact cause of elevated blood sugar levels. Meanwhile, you need to follow the following steps.

  • Do not stop taking Cephalexin without proper advice from your doctor as it is an antibiotic and the course needs to be completed to prevent the development of resistance.
  • You need to regularly monitor your blood sugar levels and keep track or record of it.
  • You need to report to your doctor if you observe any symptoms.
  • Avoid using sugary foods and drinks.
  • You need to eat a healthy diet with balanced carbohydrate portions.

However, if Cephalexin is found to be the problem of your elevated blood sugar levels then your doctor might ask you to discontinue Cephalexin and might suggest some alternative cephalosporin or antibiotic that may not interact with any of the present conditions.

In my experience

Cephalexin is not associated with elevated blood sugar levels according to the available data. Cephalexin can interact with certain other medications or other underlying conditions to affect your blood sugar levels.

Open communication with your healthcare provider is essential as they will have to determine the exact cause of elevated sugar levels if not Cephalexin and then treat you according to the requirements. Your doctor will have to monitor your sugar levels regularly to determine if you are pre-diabetic or not as sugar levels might be rising due to this.

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Castle, S. S. (2007, January 1). Cephalexin. Elsevier eBooks.


Herman, T. F. (2023, August 17). Cephalexin. StatPearls – NCBI Bookshelf.


Cephalexin (Oral Route) Side Effects – Mayo Clinic. (n.d.).