You need regular check-ups and tests with your doctor when you take metformin for diabetes. At first, your doctor needs to adjust your dose and check for side effects. Later on, you need check-ups and blood tests every 3 to 6 months to make sure your blood sugar is controlled and to check for other problems.  

Hemoglobin A1C 

Your doctor uses a blood test called the hemoglobin A1C test to find out if you are meeting your blood sugar goals. At first, your A1C is checked every 3 months. Once your blood sugar is on track, the A1C test is done every 6 months. 

Kidney Test 

It is also important to check your kidneys. The most common blood test for the kidneys is called “creatinine.” This test is usually done when you start metformin and then at least once a year. Depending on your other medical conditions, you may need this test more often.  

Metformin is removed from the body by the kidneys. If the kidneys are not working well, metformin can build up in the body. This could cause lactic acidosis, a very rare but serious side effect. Metformin does not cause kidney problems, but diabetes does. This is why people with diabetes need their kidneys checked regularly.  

Vitamin B12 

People who take metformin can sometimes have low levels of vitamin B12. This vitamin helps you make red blood cells. If your vitamin B12 is too low, you can have low numbers of red blood cells (anemia). Vitamin B12 is also important for keeping your nerves healthy. There is a blood test that can check your vitamin B12 level. This test is done at least every 2 to 3 years while you are taking metformin.  

Other Tests 

Finally, there are additional tests and exams that everyone with diabetes needs to have regularly. These are not just for people taking metformin. These include: 

  • Blood pressure checks 
  • Blood test for cholesterol levels 
  • Urine test to look for signs that diabetes is affecting your kidneys 
  • Examination of your feet 
  • Close examination of your eyes 
  • Dental check-up 


Make sure metformin is doing its best by having regular check-ups and tests!