Alternative Blood Sugar Testing Sites

Are They Safe and Accurate?

An alternative blood testing site is a body location other than your fingertip where you can reliably test your blood glucose. Common alternative blood testing sites include the palm, forearm, upper arm, thigh, and calf.

Blood Sugar Test Equipment Of White Background
Ulrike Hammerich / EyeEm / Getty Images

Using alternative body sites for blood sugar testing has been a relief to many with type 1 diabetes who have suffered from chronically sore fingers from multiple tests each day. Research suggests under normal circumstances, alternative test sites are as accurate as finger pricks. Also, the majority of (but not all) glucose meters are designed to support alternative testing.

Before you use an alternative site, discuss it with your healthcare provider. Read the instructions for your blood glucose meter and only use sites that are identified in the instructions.

Blood Glucose Results May Vary With Alternate Sites

It is important to know that blood sugar results can vary depending on when and where you test your blood. For example, if you get a sample of blood from a testing site on your thigh and your blood sugar is going up significantly at the time, you may get a delayed result. In other words, the result you receive may be what your blood sugar was 20 to 30 minutes ago but it is not accurate for the present moment. You might be able to speed up the process slightly by rubbing the area until it is warm to increase blood flow to that site.

This doesn’t mean you shouldn’t use alternative test sites but they may not give an accurate result when glucose levels are apt to change rapidly, such as after a meal, after taking insulin, during exercise or when you are sick or experiencing stress. When you need an immediate, present-moment result, such as when you suspect low blood sugar, always use a finger test site.

When Not to Use Alternative Site Testing

There are circumstances when alternative testing is not recommended. These include:

  • When you have just taken insulin
  • During or after exercise
  • If you feel you might be experiencing low blood sugar
  • When you are preparing to drive
  • When you are or suspect that you are ill
  • Do not use an alternative site unless you have discussed it with your healthcare provider first and you are able to follow his recommendations.,
  • Do not use an alternative site unless it is identified in the instructions for your blood glucose meter.

Hypoglycemic Awareness Factors Into Using Alternate Sites

Some people with diabetes also have difficulty sensing the bodily signals of low blood sugar. Their hypoglycemic awareness has been blunted over time and they may not be able to accurately assess when blood sugar is going low. Though blood sugar testing is the only way to know for certain whether glucose levels are dropping, alternative site testing is not recommended for people who struggle with hypoglycemic awareness. Discuss it with your healthcare provider before you do alternate site testing.

4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. U.S. Food and Drug Administration. Blood glucose monitoring devices.

  2. Lock JP, Szuts EZ, Malomo KJ, Anagnostopoulos A. Whole-blood glucose testing at alternate sites: glucose values and hematocrit of capillary blood drawn from fingertip and forearm. Diabetes Care. 2002;25(2):337-41. doi:10.2337/diacare.25.2.337

  3. U.S. Food and Drug Administration. How to safely use glucose meters and test strips for diabetes.

  4. Rosenthal M. Alternate-site testing. Haven't got time for the pain. Diabetes Self Manag. 2011;28(2):26-7.

By Gary Gilles
Gary Gilles is a licensed clinical professional counselor (LCPC) who has written about type 1 diabetes and served as a diabetes counselor. He began writing about diabetes after his son's diagnosis as an infant.