A1C

A1C (hemoglobin A1c, or HbA1c) is a blood test that reflects your average blood sugar over roughly the past 2–3 months. Unlike a finger-stick that captures one moment, A1C smooths out the daily ups and downs into a single trend number — which is why it’s the primary yardstick for diabetes management.

How to read it

A1C is reported as a percentage. The commonly used reference bands (in the US) are roughly:

• Below 5.7% — normal
• 5.7% to 6.4% — prediabetes
• 6.5% or higher — in the diabetes range

For someone managing type 2 diabetes, a prescriber sets an individual target (often around 7%, but it depends on the person). It’s the number your diabetes care largely revolves around.

Why it belongs in a GLP-1 glossary

Two reasons. First, GLP-1s were diabetes drugs first — their glucose-lowering effect is exactly what A1C measures, and a falling A1C is often the clearest sign the medication is working metabolically. Second, even for people taking a GLP-1 primarily for weight, an improving A1C is a meaningful non-scale victory — evidence of better health that the bathroom scale can’t show.

Tracking it

A1C is checked periodically by your clinician (typically every 3–6 months), not something you measure daily. Because it moves slowly, it’s a great trend to log alongside weight — watching A1C drop over successive lab draws is one of the more motivating records in treatment, and useful context for appointments. If you’re also on insulin or a sulfonylurea, discuss your targets and hypoglycemia risk with your prescriber, since GLP-1s lower glucose on top of those.