Average blood sugar over past 2-3 months
21 of 22 providers
Metabolic Health / Glucose
Normal:<5.7%, Prediabetes:5.7-6.4%, Diabetes:≥6.5%
HbA1c (hemoglobin A1c or glycated hemoglobin) measures the percentage of hemoglobin proteins in red blood cells that have glucose molecules attached (glycated). Because red blood cells live ~90-120 days, HbA1c reflects average blood glucose over the past 2-3 months. Unlike fasting glucose (a single snapshot), HbA1c captures long-term glycemic control and is the gold standard for diagnosing and monitoring diabetes. HbA1c ≥6.5%=diabetes;5.7-6.4%=prediabetes;<5.7%=normal (per ADA guidelines).
Here's the critical insight:"normal"HbA1c (<5.7%) is too broad and hides important metabolic risk. HbA1c of 5.5-5.7% (technically "normal") is associated with 2-3x higher risk of developing diabetes over the next decade compared to HbA1c <5.0%. For longevity optimization, target HbA1c <5.0% (ideally 4.5-5.0%)—this reflects tight glycemic control, low oxidative stress, minimal protein glycation, and optimal metabolic health. Populations with exceptional longevity (Okinawans, centenarians) have HbA1c in the 4.5-5.0% range.
HbA1c also reflects glycation burden—the non-enzymatic attachment of glucose to proteins, which causes dysfunction and accelerates aging (advanced glycation end products, or AGEs). Higher HbA1c=more systemic glycation=faster biological aging. HbA1c >5.5% is associated with increased CVD risk, cognitive decline, kidney disease, and all-cause mortality even in non-diabetics.
| Range Type | Level | Significance |
|---|---|---|
| All-cause mortality:HbA1c >5.5% (still ""normal"") associated with 10-20% higher mortality compared to <5.0%. Optimal HbA1c for longevity is 4.5-5.0%.|Biological aging (glycation):HbA1c reflects glycation burden. Advanced glycation end products (AGEs) accumulate with age and high glucose | causing protein dysfunction | inflammation |
| and accelerated aging." | Optimal (Longevity) | 4.5-5.0% |
| Exceptional glycemic control. Lowest CVD risk, mortality, and glycation burden. Target for healthspan optimization. Seen in centenarians and populations with longevity. | Good (Standard) | 5.0-5.5% |
| Normal glycemic control by standard guidelines. Acceptable for most people but room for improvement with diet optimization. | Elevated (Prediabetic Range) | 5.5-5.7% |
Prediabetes
Prediabetes per ADA criteria. 50% will develop diabetes within 10 years without intervention. Requires aggressive lifestyle changes ± metformin.
≥6.5%
Poorly Controlled Diabetes
Poor glycemic control. High risk of microvascular (retinopathy, neuropathy, nephropathy) and macrovascular (heart attack, stroke) complications. Intensify treatment.
Even modest weight loss (5-10% of body weight) significantly lowers HbA1c. Losing 10 kg (22 lbs) reduces HbA1c by 0.5-1.0%. | Visceral fat loss improves insulin sensitivity and reduces hepatic glucose production. | Combine calorie deficit with resistance training to preserve muscle mass.
Source:Exercise (Resistance + Aerobic)
Medications (if HbA1c ≥6.5% or prediabetes not responding to lifestyle)
Source:Metformin:1000-2000 mg/day. First-line for type 2 diabetes and prediabetes. Reduces hepatic glucose production, improves insulin sensitivity. Lowers HbA1c by 0.5-1.5%. | GLP-1 agonists (semaglutide, liraglutide):0.5-2.4 mg/week (injectable). Potent HbA1c reduction (1.5-2.0%), weight loss (10-15%), CV benefits. Expensive but highly effective. | SGLT2 inhibitors (empagliflozin, dapagliflozin):10-25 mg/day. Increase urinary glucose excretion. Lower HbA1c by 0.5-1.0%, reduce heart failure and kidney disease. | Insulin:Required for type 1 diabetes and advanced type 2. Titrate to HbA1c <7% (or <6.5% if safe without hypoglycemia).
HbA1c 5.7-6.4%=prediabetes (often asymptomatic). HbA1c ≥6.5%=diabetes (symptoms develop gradually).
Source:HbA1c rarely goes too low unless over-treated with insulin or sulfonylureas (causing hypoglycemia).|Hypoglycemia symptoms (blood glucose <70 mg/dL, can occur if HbA1c driven too low with medications):|Shakiness, tremors|Sweating, palpitations|Hunger, irritability|Confusion, difficulty concentrating|Dizziness, weakness|Blurred vision, headache|If severe (<50 mg/dL):Seizures, loss of consciousness, death (rare)
Type 2 diabetes:Insulin resistance + progressive beta cell failure. Caused by obesity, sedentary lifestyle, high-carb diet, genetics. Affects 10-12% of US adults.|Type 1 diabetes:Autoimmune destruction of pancreatic beta cells. No insulin production. Typically diagnosed in childhood/adolescence but can occur at any age (LADA=latent autoimmune diabetes in adults).|Prediabetes:Impaired fasting glucose (100-125 mg/dL) or impaired glucose tolerance. HbA1c 5.7-6.4%. Affects 35% of US adults.|Obesity and metabolic syndrome:Visceral fat drives insulin resistance and hyperglycemia.|Sedentary lifestyle:Physical inactivity worsens insulin resistance.|Genetics:Family history of diabetes increases risk 2-6x. Certain ethnicities (South Asian, Hispanic, African American, Native American) higher risk.|Gestational diabetes:Develops during pregnancy, resolves postpartum. 50% of women develop type 2 diabetes within 10 years.|PCOS:Insulin resistance in 70-80% of PCOS cases contributes to hyperglycemia.|Medications:Glucocorticoids (prednisone), atypical antipsychotics (olanzapine), protease inhibitors (HIV meds).|Pancreatic disease:Chronic pancreatitis, pancreatic cancer, cystic fibrosis destroy beta cells.
Source:Type 1 diabetes with excessive insulin:Over-treatment causes frequent hypoglycemia, driving HbA1c too low (<4.5%).|Type 2 diabetes with excessive sulfonylureas or insulin:Risk of hypoglycemia if HbA1c <5.5% while on these medications.|Hemolytic anemia or rapid RBC turnover:Shortened RBC lifespan means less time for glycation, falsely lowering HbA1c. Check fructosamine or continuous glucose monitoring (CGM).|Chronic kidney disease:Uremia can interfere with HbA1c assay (usually falsely lowers it).|Recent blood transfusion:Transfused RBCs haven't been exposed to patient's glucose, falsely lowering HbA1c.
HbA1c and Diabetes Diagnosis
Source:HbA1c ≥6.5% is diagnostic for diabetes (must be confirmed with repeat test). HbA1c 5.7-6.4%=prediabetes. ADA recommends HbA1c over fasting glucose or OGTT due to convenience (no fasting required) and better reflection of long-term glycemic control. However, HbA1c may miss some cases detected by OGTT (post-meal glucose spikes).
| Provider | Includes | Annual Cost | Biomarkers |
|---|---|---|---|
 Superpower | ✓ | $199 | 100+ (150 with ratios) |
 WHOOP Advanced Labs | ✓ | $349 | 65 |
 Labcorp OnDemand | ✓ | $398 | 30+ |
| ✓ | $486 | 40+ | |
| ✓ | $468 | 83 | |
| ✓ | $349 | 100+ | |
 InsideTracker | ✓ | $680 | 54 |
 Function Health | ✓ | $365 | 100+ |
| ✓ | $250 | 65 | |
| ✓ | $495 | 70+ | |
| ✓ | $895 | 100+ | |
| ✓ | $1950 | 150+ | |
| — | $399 | 100+ | |
| — | $Varies | 75+ | |
| ✓ | $190 | 100+ | |
| ✓ | $99 | 50 | |
| ✓ | $125 | 60 | |
| ✓ | $199 | 50 | |
| ✓ | $499 | 120+ | |
| ✓ | $4188 | 80+ | |
| ✓ | $375 | 85 | |
| ✓ | $700 | 129 |
21 providers include this biomarker in their panels
This information is for educational purposes only and is not medical advice. Always consult with a qualified healthcare provider about your specific health needs.
