Alternative Site Testing (AST) for Blood Draw

Although fingers are the most common place to draw blood for testing, you can also test on your palms, forearm, upper arm, and above the knee.

Important: There are limitations with AST (Alternative Site Testing). Please consult your health care professional before you perform AST.

When to use AST?

Food, medication, illness, stress and exercise can affect ketone levels. Capillary blood at the fingertip reflects these changes faster than capillary blood at other sites. Thus, when testing ketones during or immediately after a meal, physical exercise, or any other event, take a blood sample from your finger only.

We strongly recommend that you perform AST ONLY at the following times:

• • In a pre-meal or fasted state (more than 2 hours since the last meal).
  • Two hours or more after taking insulin.
  • Two hours or more after exercise.

Do not use AST if:

• • You think your ketones are low.
  • Your AST results do not match the way you feel.
  • Your routine ketone results often fluctuate