Quick Facts
- Sample: Blood draw
- Fasting: Not required
- Turn-around: 3–5 business days. May take longer based on weather, holiday, or lab delays.
Benefits
- Detect hidden glucose spikes that A1C testing might miss
- Get faster feedback on dietary and medication changes (1-2 weeks vs 2-3 months)
- Monitor post-meal blood sugar control more effectively than standard tests
- Complement A1C testing for comprehensive diabetes management
- Track SGLT2 inhibitor effectiveness with specialized interpretation guidelines
- Empower self-management with more detailed glucose control insights
Who Is This Test For?
- People with diabetes seeking to optimize glucose management between A1C tests
- Individuals with seemingly controlled A1C who suspect post-meal glucose spikes
- Patients taking SGLT2 inhibitors who need specialized monitoring
- Those making dietary changes and wanting timely feedback on effectiveness
- Anyone experiencing frequent urination, excessive thirst, or unexplained fatigue
- Patients with insulin resistance requiring detailed glucose management insights
How It Works – Just 3 Steps
- Order online – No doctor's visit required; order directly through Walk-In Lab
- Visit lab location – Quick blood draw at your nearest partner facility
- Get results – Confidential results in secure online portal within in 3-5 days
FAQ
What does the GlycoMark test measure? It measures 1,5-anhydroglucitol (1,5-AG), a biomarker that reveals recent glucose spikes over the past 1-2 weeks, particularly after meals.
How is this different from A1C testing? While A1C shows average glucose over 2-3 months, GlycoMark specifically detects postprandial glucose spikes over 1-2 weeks and responds more rapidly to treatment changes.
Do I need to fast for this test? No fasting is required. The test can be performed at any time of day, regardless of when you last ate.
What if I'm taking SGLT2 inhibitors? These medications naturally lower GlycoMark levels to ≤2 μg/mL. Levels above 2 μg/mL might indicate medication non-compliance or reduced effectiveness.
How often should I get tested? Consider testing every 2-4 weeks when monitoring treatment changes, or as recommended by your healthcare provider for ongoing diabetes management.
What do abnormal results mean? Lower GlycoMark values indicate recent hyperglycemic episodes. Levels below 2 μg/mL suggest persistent glucose spikes requiring attention.
More Details
What is the purpose of this test?
The GlycoMark test measures 1,5-anhydroglucitol (1,5-AG), a specific biomarker that provides insight into postprandial (after-meal) glucose levels over the previous 1-2 weeks (LabCorp 2025). Unlike standard glucose tests that provide point-in-time measurements or A1C tests that average glucose over 2-3 months, GlycoMark specifically detects recent hyperglycemic excursions that may not be evident from other testing methods.
This FDA-cleared test is particularly valuable for identifying "hidden" glucose spikes that can occur after meals, even when A1C levels appear to be in good control (BioSpace 2008). The test has been validated through extensive clinical research, including the DURABLE trial involving 2,094 patients from 11 countries.
Who would benefit from this test?
People with diabetes seeking intermediate-term monitoring between A1C tests would find GlycoMark particularly beneficial. This includes individuals with seemingly well-controlled diabetes based on A1C who may still experience significant postprandial hyperglycemia—a condition affecting nearly 40% of patients deemed to be in "good control" (GlycoMark Inc. 2018).
Patients taking SGLT2 inhibitors require specialized monitoring, as these medications cause persistent glycosuria that significantly affects GlycoMark interpretation (Diabetes Journals 2019). The test is also valuable for those making dietary changes or medication adjustments who want feedback sooner than A1C testing can provide.
When should I order the GlycoMark Blood Test?
Consider ordering when your A1C appears controlled but you suspect post-meal glucose spikes are occurring. The test is particularly useful when you've recently changed medications or diet and want feedback within 1-2 weeks rather than waiting 2-3 months for A1C changes to become apparent.
If you're taking SGLT2 inhibitors, regular GlycoMark testing can help assess medication effectiveness and compliance. You should also consider this test if you need more frequent monitoring between routine A1C tests or if you're experiencing symptoms like frequent urination, excessive thirst, or unexplained fatigue that might indicate glucose control issues.
How do I interpret the results?
GlycoMark ≥10 μg/mL
- What it means: Normal glucose control
- Typical action: Continue current management
GlycoMark 2–10 μg/mL
- What it means: Some glucose elevation
- Typical action: Review diet and medication timing
GlycoMark <2 μg/mL
- What it means: Persistent hyperglycemia
- Typical action: Consult provider for treatment adjustment
GlycoMark <2 μg/mL (on SGLT2 inhibitors)
- What it means: Expected medication effect
- Typical action: Normal; indicates drug is working
GlycoMark >2 μg/mL (on SGLT2 inhibitors)
- What it means: Possible non-compliance
- Typical action: Discuss medication adherence with provider
Normal GlycoMark levels are approximately 10 μg/mL, with lower values indicating recent episodes of hyperglycemia (LabCorp 2025).
Disclaimer: Reference ranges may vary by laboratory. Listed ranges are general guidelines and may differ from those used by the performing lab. Always consult your healthcare provider for interpretation.
Pre-test preparation
No special preparation or fasting is required for the GlycoMark test. Continue taking all medications as prescribed, including diabetes medications. The test can be performed at any time of day, regardless of meal timing or when you last ate.
If you're taking SGLT2 inhibitors, make sure to note this when ordering the test, as it significantly affects result interpretation. The medication causes naturally low GlycoMark levels, and this information is crucial for proper analysis of your results.
How often should I get tested?
- Monitoring treatment changes: Every 2–4 weeks
- Stable diabetes management: Every 3–6 months
- Taking SGLT2 inhibitors: Every 1–3 months
- Poor glucose control: Every 2–4 weeks
- Dietary modifications: Every 4–6 weeks
Why early detection matters
Postprandial hyperglycemia is associated with increased cardiovascular complications, making early detection crucial for preventing long-term health issues. Glycemic variability, independent of overall glycemic control, has emerged as a prognostic marker for major adverse cardiovascular events in patients with type 2 diabetes (Nature 2024).
The GlycoMark test can identify glucose control issues before they become apparent through other testing methods, allowing for earlier intervention and treatment adjustments. This proactive approach helps reduce the risk of diabetes-related complications including heart disease, nerve damage, and other serious health problems.
Related tests you may consider
Hemoglobin A1C— complements GlycoMark by providing a longer-term (2-3 month) average of blood glucose levels. Using both tests together offers comprehensive diabetes management insights.
Fasting Plasma Glucose — provides a point-in-time measure that, when paired with GlycoMark, offers insight into both fasting and postprandial glycemic control patterns.
Glucose Tolerance Test, 2-Hour — provides detailed information about how your body processes glucose over several hours, offering comprehensive insight when combined with GlycoMark's intermediate-term monitoring capabilities.
