Complete Testing & Optimization Guide
Optimal ranges, provider comparison, and strategies to improve your Hemoglobin A1c (HbA1c) levels
Included in 10 of 10 major testing providers
Metabolic Health / Glucose
Normal:<5.7%, Prediabetes:5.7-6.4%, Diabetes:≥6.5%
Abnormal Hemoglobin A1c (HbA1c) levels can indicate underlying health issues that may go undetected without proper testing. Regular monitoring helps catch problems early when they're most treatable.
Understanding your Hemoglobin A1c (HbA1c) levels enables targeted interventions, tracks treatment effectiveness, and helps optimize your overall health and performance.
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.
Bottom line: TSH and Free T4 alone miss people with conversion problems. Free T3 is the only way to know if you have enough active thyroid hormone at the tissue level.
| Range Type | Level | Clinical 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% |
Standard lab range:Normal:<5.7%, Prediabetes:5.7-6.4%, Diabetes:≥6.5%
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.
Note: >9.0%
Note: Low-Carb or Ketogenic Diet (Most Effective)
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 Test | Annual Cost | Total Biomarkers |
|---|---|---|---|
 Superpower | ✓ | $199 | 100+ |
 WHOOP Advanced Labs | ✓ | $349 | 65 |
 Labcorp OnDemand | ✓ | $398 | 30+ |
| ✓ | $486 | 40+ | |
| ✓ | $468 | 83 | |
| ✓ | $798 | 100+ | |
 InsideTracker | ✓ | $680 | 48 |
 Function Health | ✓ | $499 | 100+ |
| ✓ | $900 | 70+ | |
| ✓ | $1150 | 110 | |
| — | $Varies | 75+ |
Choose from 10 providers that include this biomarker in their panels
Hemoglobin A1c (HbA1c) is a metabolic health / glucose biomarker that Average blood sugar over past 2-3 months The normal reference range is Normal:<5.7%, Prediabetes:5.7-6.4%, Diabetes:≥6.5%. Regular testing helps track changes and identify potential health issues early.
10 out of 10 major blood testing providers include Hemoglobin A1c (HbA1c) in their standard panels. These include Superpower, Blueprint, Mito Health and others.
For most people, testing Hemoglobin A1c (HbA1c) 2-4 times per year is recommended to establish baseline levels and track trends. If you have abnormal results or are actively working to optimize this biomarker, more frequent testing (quarterly) may be beneficial. Always consult with your healthcare provider for personalized testing frequency recommendations.
The standard laboratory reference range for Hemoglobin A1c (HbA1c) is Normal:<5.7%, Prediabetes:5.7-6.4%, Diabetes:≥6.5%. However, many functional medicine practitioners recommend tighter "optimal" ranges for peak health and performance. Your ideal range may vary based on your age, sex, health goals, and other individual factors. Work with a healthcare provider familiar with optimal ranges to determine your target levels.
Most direct-to-consumer blood testing services that include Hemoglobin A1c (HbA1c) provide the physician order as part of their service. However, some states have restrictions on direct-to-consumer testing. Check with your chosen provider about availability in your state and whether they provide the necessary physician authorization.
Gold standard for diabetes diagnosis and management. Reflects glycemic control over time. Each 1% reduction decreases diabetes complications significantly.
This information is for educational purposes only and is not medical advice. Always consult with a qualified healthcare provider about your specific health needs and before making decisions about blood testing.
