MetabolicMarkers

Educational content only, not medical advice. We are not a medical provider; review your results with a licensed physician. Details

Current promotion

Prediabetes Testing: HbA1c, Fasting Insulin & Glucose Tolerance

Catch shifts in blood sugar and insulin early, while lifestyle changes have the most room to work.

Affiliate disclosure: we earn a commission when you purchase lab tests through links on this site, at no extra cost to you. Learn more

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Individual tests from $14.15 and bundled panels from $35.92 with code DH20 (promotional pricing at time of writing).

At a glance

Prediabetes testing measures the blood markers that tend to shift earliest when the body starts struggling to regulate glucose: HbA1c, fasting glucose, fasting insulin, C-peptide, and the response to a measured glucose drink. This collection lets you order those tests online without a doctor's visit and get private results to review with your clinician. It is best suited to adults with risk factors, family history, excess weight, hypertension, high triglycerides, or PCOS, who want an early, objective baseline.

Best suited for

  • Adults with a family history of type 2 diabetes who want an early, objective baseline
  • People with risk factors associated with insulin resistance, such as excess weight, hypertension, high triglycerides, or PCOS
  • Anyone told a past glucose or HbA1c result was borderline and who wants to follow the trend
  • People making diet, exercise, or sleep changes who want before-and-after markers to review with their doctor

What's included

Hemoglobin A1c (HbA1c)

Fasting Plasma Glucose

Insulin (Fasting)

C-Peptide

Glucose Tolerance Test, 2 Specimens, 75g

Insulin Response to Glucose Test, 2 Specimens

Fructosamine

Lipid Panel

C-Reactive Protein (CRP)

Urine Albumin-to-Creatinine Ratio (uACR)

Comprehensive Metabolic Panel (CMP)

DH-1 Diabetes Health Panel (CMP + HbA1c)

DH-3 Diabetes Health Panel (adds CBC, Lipid Panel, CRP, Insulin, urine microalbumin)

DH-4 Diabetes Health Panel (adds glucose tolerance and insulin response)

Deep-dive the key markers: Fasting Glucose, HbA1c, Fasting Insulin, LDL-C, HDL-C, Triglycerides, eGFR, ALT

Key biomarker ranges

Commonly used adult reference ranges for markers this panel measures, labs vary, so always interpret results against your lab's stated ranges and with your doctor.

Fasting Glucose (mg/dL)

Commonly used reference ranges place fasting glucose at 70–99 mg/dL; results vary with sleep, stress, and recent illness, and labs differ slightly.

Fasting Glucose reference ranges (mg/dL)
ZoneRange
Low5070 mg/dL
Optimal70100 mg/dL
Prediabetic range100126 mg/dL
Diabetic range126160 mg/dL
Hemoglobin A1c (%)

Commonly used reference ranges place HbA1c below 5.7%; conditions affecting red blood cells can skew results, so labs and clinicians interpret in context.

Hemoglobin A1c reference ranges (%)
ZoneRange
Optimal45.7 %
Prediabetic range5.76.5 %
Diabetic range6.510 %
Fasting Insulin (µIU/mL)

Commonly used reference ranges accept up to ~25 µIU/mL, but many clinicians view single-digit fasting insulin as the more informative target; assays vary by lab.

Fasting Insulin reference ranges (µIU/mL)
ZoneRange
Low02 µIU/mL
Optimal210 µIU/mL
Above optimal1025 µIU/mL
High2530 µIU/mL

The importance of testing

Standard checkups often stop at a single fasting glucose reading, which can stay in range for years while insulin quietly climbs to keep it there. Fasting insulin and C-peptide show how hard your body is working behind the scenes, and the two-specimen glucose tolerance and insulin response tests show what happens after a measured 75-gram glucose load. These are the markers associated with insulin resistance that many people track well before glucose itself moves.

HbA1c adds the long view, your average glucose over the past two to three months, while fructosamine reflects the most recent two to three weeks. Together with fasting glucose, they help you and your doctor distinguish a one-off reading from a genuine trend.

Context markers round out the picture, because insulin resistance rarely appears in isolation. A lipid panel, CRP, the urine albumin-to-creatinine ratio, and a comprehensive metabolic panel cover the cardiometabolic and kidney markers commonly reviewed alongside blood sugar, and the bundled DH panels combine them into single orders.

The payoff of testing early is time: an objective baseline while numbers are still borderline gives you and your clinician the widest window to act on diet, activity, and sleep, and repeat testing shows whether those changes are moving your markers.

Promo code

DH20

Save 20% with code DH20, current promotion; confirm final pricing on the partner page.

Ready to get your numbers? Order online, visit a nearby draw site, and receive private results to review with your doctor.

Order Now

Frequently asked questions

What tests screen for markers associated with prediabetes?

HbA1c and fasting glucose are the standard starting points, showing your two-to-three-month average and your current fasting level. Adding fasting insulin, C-peptide, or a two-specimen glucose tolerance test gives earlier insight into markers associated with insulin resistance, which often shift before glucose does.

Can I order prediabetes tests without seeing a doctor first?

Yes, no doctor's appointment is needed to order, because the partner lab provides the physician-authorized requisition. You order online, visit one of about 2,100 draw sites, and results post privately to your portal, often within 24 to 48 hours, to review with your own clinician.

What is the difference between fasting glucose and fasting insulin testing?

Fasting glucose measures the sugar in your blood at that moment, while fasting insulin measures the hormone your body is producing to keep that sugar in range. Insulin can rise for years while glucose stays normal, which is why many people track both when watching for markers associated with insulin resistance.

Do I need to fast before prediabetes testing?

Yes, for most of these tests, fasting glucose, fasting insulin, and lipid panels typically require 8 to 12 hours of fasting, and the glucose tolerance tests are performed fasted before the glucose drink. HbA1c usually does not require fasting; follow the prep instructions provided at checkout.

Is this testing available in every state?

No, direct-to-consumer lab testing is restricted or prohibited in New York, New Jersey, and Rhode Island, so residents of those states may be blocked at the partner's checkout. Availability of specific tests, such as the oral glucose tolerance test, can also vary by location.