Skip main navigation



What is alternate site testing?


The term alternate site testing (AST) means using parts of the body other than the fingertips to obtain blood for blood glucose testing. Alternate site testing offers fingertip protection and less pain. Alternate site testing areas can be the upper arm, thigh, calf and the fleshy parts of the hand.

Various blood glucose meters offer alternate site testing in addition to finger-stick testing. Our blood glucose meter comparison chart shows which meters allow AST.

When should you alternate site test (AST)?

  • In a pre-meal or fasting state (more than two hours since your last meal)
  • Two hours or more after taking insulin
  • Two hours or more after exercise

Whenever you feel that your glucose level is changing rapidly, the fingertip measurement is more accurate than alternate site testing. AST is not recommended for pregnant women. In addition, readings before meals are more accurate than after meals.

Remember: Fingerstick testing is still important.

Be sure to check your blood glucose monitor owner's manual and consult your healthcare professional or diabetes educator for information and instruction on alternate site testing.

Find comprehensive information in our Diabetes Center.

Back to Ask a Pharmacist


Answers to questions regarding information about medications or health conditions are not for diagnostic or treatment purposes and are not conclusive as to the presence or absence of any health condition. Consult your physician for diagnosis and treatment of your medical condition. The information provided is not a substitute for medical advice. Advances in medicine may cause this information to become outdated, invalid or subject to debate. Professional opinions and interpretations of the scientific literature may vary. Walgreens' terms of use and general warranty disclaimer apply to all services provided. If you are in need of immediate medical attention, contact your physician, poison control center or emergency medical professional. If you need to speak with a pharmacist for non-emergency matters, contact your local Walgreens pharmacist or call a pharmacist toll-free at 1 (877) 250-5823.

Your Digital Health Advisor. Powered by WebMD. Manage diabetes with this easy online tool.* Get started.
Your Digital Health Advisor. Powered by WebMD. Manage diabetes with this easy online tool.* Get started.

Balance Rewards for Healthy Choices

20 Points
20 Points

Now you can track your blood pressure and blood glucose.

Start earning points Go Arrow