Glucose Tolerance Test (OGTT)
Type
Blood Testing
Biomarkers
3
Duration
3 hours
Results
24 hours
2-hour oral glucose tolerance test for diabetes screening.
Diabetes and metabolic screening tests measure how well your body processes glucose — your primary fuel source. Fasting glucose gives a snapshot of your blood sugar after an overnight fast, while HbA1c reveals your average blood sugar over the past 2–3 months by measuring the percentage of hemoglobin proteins coated with sugar. An insulin test can detect insulin resistance — where your cells stop responding efficiently to insulin — often years before blood sugar levels rise into the diabetic range. This early detection window is critical because prediabetes and insulin resistance are reversible with lifestyle changes, while advanced type 2 diabetes requires lifelong management.
Key Details
- Biomarkers
- 2–4 metabolic markers
- Fasting Required
- Yes, 10–12 hours for fasting glucose
- Sample Type
- Blood draw
- Turnaround
- Same day to 24 hours
- Common Use
- Diabetes screening, insulin resistance detection
Who Is This For?
Adults over 35 as part of routine screening (diabetes affects 1 in 10 adults globally). Anyone with a family history of type 2 diabetes. People who are overweight or physically inactive. Those experiencing increased thirst, frequent urination, unexplained weight loss, or fatigue. Women with a history of gestational diabetes or polycystic ovary syndrome (PCOS).
What's Included
Preparation Required
Fasting for 10–12 hours before your appointment is recommended for accurate results (water is fine). Avoid alcohol for 24 hours and intense exercise for 12 hours before the blood draw. Morning appointments are ideal for consistent hormone and glucose readings. The blood draw typically takes 5–10 minutes.
- Category
- Diagnostic
- Sample Type
- Blood draw
- Duration
- 3 hours
- Results
- 24 hours