HbA1c (IFCC)
MetabolicAlso known as: glycated hemoglobin, glycosylated hemoglobin, A1C, hemoglobin A1c, Zuckergedächtnis
Glycated hemoglobin according to International Federation of Clinical Chemistry standards.
It's an alternative measurement system for HbA1c that uses different units (mmol/mol) than NGSP (percentage).
Why this matters
Elevated IFCC HbA1c signals prolonged high blood sugar, contributing to long-term diabetes-related complications. Lifestyle factors affecting levels include diet (reducing added sugars and refined carbs, increasing fiber and lean protein intake), regular exercise, maintaining a healthy weight, good sleep hygiene, and stress reduction. Monitoring IFCC HbA1c helps track glucose control and supports early interventions to reduce health risks.
How this connects to other biomarkers
- HbA1c (IFCC, mmol/mol) is the international SI-unit equivalent of HbA1c (NGSP) in % — conversion: NGSP% = 0.0915 × IFCC + 2.15.
- Interpretation thresholds, confounders, and clinical relationships are identical to HbA1c (NGSP): ≥ 48 mmol/mol defines diabetes; falsely altered values occur with red-cell breakdown (hemolysis) or shortened red-cell survival.
How often should I test HbA1c (IFCC)?
Most adults benefit from one HbA1c screening test per year. If you're managing a glycemic concern such as pre-diabetes, diabetes, or actively working on insulin sensitivity, retest every three to six months.
At baseline / for screening: Once every 12 months from age 30 as part of a cardiometabolic check. More frequently, every 3 to 6 months, if you have pre-diabetes, type 2 diabetes, polycystic ovary syndrome, or a family history of any of these.
When monitoring an intervention or change: Retest 8 to 12 weeks after a sustained lifestyle change, such as reducing refined carbs and added sugars, increasing physical activity, meaningful weight loss, or improving sleep quality. The same window applies after starting or adjusting glucose-lowering medication (metformin, GLP-1 receptor agonist, SGLT2 inhibitor). If a result was above target, reconfirm sooner once you've begun addressing the most likely driver.
Note: Iron deficiency, recent transfusion, hemoglobinopathies, and stage 4 to 5 CKD distort HbA1c. In those situations, retest more frequently using fasting glucose or fructosamine (which reflects 2 to 3 weeks of glucose) while the underlying condition is addressed.
Frequently asked questions
Included in
Ready to check your health?
Get a comprehensive view of your biomarkers with our advanced check-up packages.