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Body measures and lab tests

A1C

A1C is a blood test that reflects your average blood sugar over roughly the past 3 months, reported as a percentage.

Clinician review pending Updated Body measures and lab tests
DefinitionA1C is a blood test that reflects your average blood sugar over roughly the past 3 months, reported as a percentage.

What it means

Sugar in the blood sticks to hemoglobin in red blood cells. Since red cells live about 3 months, the share of hemoglobin carrying sugar gives a running average.

  • Below 5.7%: normal
  • 5.7% to 6.4%: prediabetes
  • 6.5% or higher: diabetes

Lowering A1C was the first goal GLP-1 medicines were approved for. Many people on Ozempic or Mounjaro track A1C alongside weight. Conditions that affect red blood cells, like anemia, can make A1C less accurate.

Many adults with diabetes aim for an A1C under 7%, but the right target depends on age, other conditions and the risk of lows. Your care team sets that goal with you. Labs report it the same way across the US, so results from different clinics can usually be compared.

Why it matters

A1C is how diabetes benefit is measured in trials, separate from weight change.

Related terms

Type 2 diabetesHypoglycemiaIncretinOzempic (semaglutide)Mounjaro (tirzepatide)

Clinician review pending. Drafted from primary sources and waiting for sign-off by a licensed clinician (MD, DO or PharmD) before launch. Every number is checked against its source. Drug facts are re-checked quarterly, prices monthly and whenever a label changes. How we review · Report an error