HbA1c
This blood test shows your average blood sugar over the past 3 months — a much better snapshot than a single fasting glucose reading.
Your HbA1c tells you how well your body has been handling blood sugar over the past 90 days. It's the single best marker for metabolic health — and it matters even more for Indians, who develop insulin resistance at lower BMIs than Western populations.
Good for you if: You want to understand your metabolic health, have a family history of diabetes, are over 25, or want to track the effect of dietary changes on your blood sugar.
Dive deeper into the scienceWhat is this test?
HbA1c measures the percentage of your red blood cells' haemoglobin that has glucose permanently attached to it. Since red blood cells live about 90–120 days, this gives you a rolling 3-month average of your blood sugar — not just what it was this morning.
Unlike fasting glucose, which can swing wildly based on last night's dinner, stress, or how well you slept, HbA1c smooths all of that out. Someone whose blood sugar spikes sharply after every meal but returns to normal fasting levels will show a normal fasting glucose but an elevated HbA1c — revealing the true metabolic picture.
What your number means
| HbA1c | What it means | What to do |
|---|---|---|
| <5.2% | Optimal — longevity target | Maintain current habits; test annually |
| 5.2–5.6% | Normal — room to optimise | Good range; focus on prevention |
| 5.7–6.4% | Pre-diabetic | Lifestyle intervention now; berberine; retest in 3 months |
| 6.5–7.4% | Diabetic (mild–moderate) | See your doctor; medication + lifestyle changes |
| ≥7.5% | Diabetic (poor control) | Urgent physician review |
Research shows cardiovascular risk starts climbing from HbA1c as low as 4.6% — there's no clearly "safe" plateau. For Indians with genetic susceptibility to metabolic syndrome, aiming for the low end of normal (<5.2%) rather than just "not pre-diabetic" (<5.7%) is a meaningful longevity intervention.
How to improve it
Cut refined carbs — white rice, maida, added sugar, and sweetened drinks are the primary dietary drivers of elevated glucose in India. Swap to millets, dal-rice combos, and lower-glycaemic options.
Walk after meals — a 15–20 minute walk after eating blunts your glucose spike by diverting sugar into active muscles. Simple and highly effective.
Resistance training 2–3×/week builds muscle, which is your body's primary glucose disposal organ. More muscle = better blood sugar control.
- Berberine — 500mg 3×/day with meals; comparable to metformin in several studies (0.5–1.5% HbA1c reduction)
- Myo-inositol — 2–4g/day, especially effective for insulin resistance and PCOS
- Sleep quality — even one night of poor sleep raises fasting glucose by 10–15 mg/dL; chronic sleep deprivation substantially impairs insulin sensitivity
- Stress management — cortisol directly raises blood glucose; meditation, exercise, and sleep all help
Want to track your HbA1c?
eterni connects your lab results into a trajectory — so you see trends, not just a number.
Get early accessFrequently Asked Questions
What is a good HbA1c level?
Clinical guidelines call anything below 5.7% normal. But from a longevity perspective, you want to be below 5.2%. Research shows cardiovascular risk starts rising from HbA1c as low as 4.6% — so tighter is better, especially for South Asians with higher metabolic risk.
How can I lower my HbA1c naturally?
The most effective approaches: cut refined carbs (white rice, maida, sugar), do resistance training 2–3 times a week, walk 15–20 minutes after meals, try berberine 500mg three times daily, and improve your sleep. Combined, these can reduce HbA1c by 0.5–1.5% over 3 months.
How often should I test HbA1c?
If your HbA1c is above 5.5%, test every 3 months until you get it down. Below 5.2% and stable? Once a year is fine. Since the test reflects a 90-day window, testing more often than every 8 weeks won't tell you much new.
What's the difference between HbA1c and fasting glucose?
Fasting glucose is a single-moment snapshot — affected by last night's dinner, stress, and sleep. HbA1c is your 90-day average, based on glucose permanently bonded to haemoglobin. HbA1c is more reliable. Ideally run both alongside fasting insulin for the complete metabolic picture.
How it's measured
The test is a simple blood draw — no fasting required. Labs measure the percentage of haemoglobin with glucose attached using methods like HPLC (High Performance Liquid Chromatography) or immunoassay. Results are reported as a percentage. The test costs ₹300–600 at most major Indian labs.
Clinical ranges vs optimal ranges
Standard clinical guidelines (ADA, WHO) define normal as below 5.7%, pre-diabetes as 5.7–6.4%, and diabetes as 6.5% or above. These thresholds were designed to diagnose disease — not to optimise health.
The EPIC-Norfolk study and the Emerging Risk Factors Collaboration both showed that cardiovascular risk increases linearly with HbA1c starting from 4.6%. For longevity, the target is below 5.2% — staying in the lower portion of "normal" rather than just avoiding the pre-diabetes label.
India-specific considerations
India has one of the highest rates of pre-diabetes and type 2 diabetes globally. South Asian genetics cause significant insulin resistance at lower BMI — a lean Indian may be metabolically at risk when Western charts suggest otherwise. Standard "normal" ranges were developed on Western populations and may not apply.
India also has a relatively high prevalence of haemoglobin variants (HbS, HbC, thalassaemias) that can cause falsely low or high HbA1c readings. If you're from populations with higher variant frequencies, request HPLC methodology for more accurate results.
Connected supplements
- Berberine — activates AMPK, comparable to metformin for glucose and insulin metrics
- Myo-inositol — insulin second messenger; especially effective in PCOS and metabolic syndrome
- Chromium picolinate — may modestly improve insulin sensitivity in deficient individuals
- Magnesium — deficiency impairs insulin signalling; 200–400mg/day glycinate or threonate
Know what's working. Know what's not.
eterni connects your lab results, supplements, and retests — so you can see the trajectory, not just a snapshot.
Join the waitlist