Glucose Tolerance Test (GTT), Two-hour (Oral WHO Protocol)
Access Labcorp Draw
Sample type: Serum
Requires fasting: Yes
Phlebotomy required
Details
The Glucose Tolerance Test (GTT), Two-hour (Oral WHO Protocol) evaluates the body's ability to metabolize glucose by measuring blood glucose levels before and two hours after consuming a standardized glucose solution. It is used to diagnose glucose intolerance, type 2 diabetes, and gestational diabetes in pregnant women. This test is particularly useful for patients with borderline fasting or postprandial glucose levels and in the investigation of conditions like unexplained hyperglycemia, hypertriglyceridemia, and other metabolic abnormalities.
- Glucose, 2-hour (post 75 g glucose PO)
- Glucose, Fasting
Estimated days for results: Results should arrive 1 - 2 business days after the lab receives samples.
1–2 business days
- Fasting before a blood draw means you don't eat or drink anything except water.
- Your doctor should provide any special instructions related to fasting for your test. Always follow your doctor's instructions.
If possible, stop taking nonessential medications that can affect blood sugar (glucose) at least 3 days before your blood draw. DO NOT discontinue any prescription medications without first consulting your healthcare provider.
Blood Draw Options with Fullscript
Fullscript offers several convenient phlebotomy options to complete your lab testing:
Access Labcorp Draw – Labcorp PSC
- Location: Visit a nearby Labcorp Patient Service Center.
- Cost: $10 sample collection fee (paid during checkout).
- Scheduling: Schedule your appointment here. Appointments are recommended to reduce wait times. Walk-ins are accepted, but may experience delays. Aim to arrive 15 minutes before your appointment.
- Collection Instructions:
- Bring a valid ID.
- Bring your digital or printed requisition form, available in the Labs tab of your Fullscript account.
- Check-in: Follow check-in kiosk steps when you arrive at the Labcorp draw site.
- More Info: Access Labcorp blood draw guide
Getlabs Mobile Phlebotomy
- Location: Sample collection at your home or office.
- Cost: $85 sample collection fee (paid during lab order checkout).
- Availability: Available in most locations – enter your ZIP code during checkout to confirm.
- Scheduling: Schedule your appointment here through your Fullscript account.
- Collection Instructions:
- Have your digital or printed requisition form and valid ID ready.
- Your phlebotomist will contact you by phone to coordinate arrival.
- More Info: Getlabs blood draw guide
State restrictions:
Patient can't order this test if they are located in Hawaii, Puerto Rico, New Jersey, New York, or Rhode Island




