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Estimating Your New HbA1c When Changing Your Medications and Supplements:
Range:
7-Point Blood Glucose Average → Estimated HbA1C
Aim for at least 7 readings spaced out across the day, all in mg/dL:
Note: snacks between meals near a fingerstick reading can throw off the calculation.
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Estimated Average Glucose (eAG):
mg/dL
Estimated HbA1c:
IFCC units:
mmol/mol
0 of 7 readings entered
eAG = (Before breakfast + 2 hrs after breakfast + Before lunch + 2 hrs after lunch + Before dinner + 2 hrs after dinner + Bedtime) ÷ 7.
HbA1c estimated from eAG using the ADAG study's own reverse regression: HbA1c (%) = (eAG (mg/dL) + 46.7) ÷ 28.7,
and in IFCC units: HbA1c (mmol/mol) = 10.929 × ((eAG (mmol/L) + 2.5944) ÷ 1.5944 − 2.15). Estimate only, not a substitute for a lab-drawn HbA1c.
Nathan DM, Kuenen J, Borg R, Zheng H, Schoenfeld D, Heine RJ; A1c-Derived Average Glucose (ADAG) Study Group. Translating the A1C Assay Into Estimated Average Glucose Values. Diabetes Care. 2008;31(8):1473–1478. PMC2850190 · DOI: 10.2337/dc08-0545
Nathan DM, Kuenen J, Borg R, Zheng H, Schoenfeld D, Heine RJ; A1c-Derived Average Glucose (ADAG) Study Group. Translating the A1C Assay Into Estimated Average Glucose Values. Diabetes Care. 2008;31(8):1473–1478. PMC2850190 · DOI: 10.2337/dc08-0545
Correlating Fasting Glucose with HbA1C
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mg/dL
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Estimate HbA1C Based on Your Current Fasting Glucose:
Estimate only, using HbA1c (%) ≈ 2.6 + 0.03 × FPG (mg/dL) — a heuristic derived by inverting the ADAG eAG/HbA1c relationship under a steady-state assumption, not a directly reported clinical regression. Not a substitute for a lab-drawn HbA1c. A correction factor of +/- 0.1 for HbA1C in some results was added on by Dr. Benjamin Brewer to reflect a more precise calculation corresponding to universally accepted standards.
Source
Free
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Click “Start” to preview beginning a medication/supplement, “Continue” if unchanged, or “Stop” if discontinued since your last reading — results vary with compliance and optimal dosage. For more information, click the manufacturer link below in blue.
Medications and Supplements (use arrow keys or green bar to switch choices)
Dopamine Agonists
Bromocriptine (Cycloset) VeroScience
GLP-1 Receptor Agonists
Albiglutide (Tanzeum (Disc.)) GSK
Dulaglutide (Trulicity) Eli Lilly
Efpeglenatide (Efpeglenatide) Hanmi Pharm
Exenatide (Short-acting) (Byetta) AstraZeneca
Exenatide (Weekly) (Bydureon) AstraZeneca
Liraglutide (Victoza) Novo Nordisk
Lixisenatide (Adlyxin) Sanofi
Semaglutide (Injectable) (Ozempic/Wegovy) Novo Nordisk
Semaglutide (Oral) (Rybelsus) Novo Nordisk
Amylin Analogs
Pramlintide (Symlin) AstraZeneca
Bile Acid Sequestrants
Colesevelam (Welchol) Cosette Pharma
Dual GIP/GLP-1 Agonists
Tirzepatide (Mounjaro) Eli Lilly
SGLT2 Inhibitors
Canagliflozin (Invokana) Janssen (J&J)
Dapagliflozin (Farxiga) AstraZeneca
Empagliflozin (Jardiance) Eli Lilly
Ertugliflozin (Steglatro) Merck
Supplements II
Apple cider vinegar (Apple Cider Vinegar) Bragg
Cinnamon (Ceylon) (Ceylon Cinnamon) NOW Foods
Ginger powder (Organic Ginger) Simply Organic
Biguanides
Metformin (Glucophage) BMS
DPP-4 Inhibitors
Alogliptin (Nesina) Takeda
Linagliptin (Tradjenta) Eli Lilly/BI
Saxagliptin (Onglyza) AstraZeneca
Sitagliptin (Januvia) Merck
© 2026 Benjamin Brewer, MD
· Clinical Evidence