Glucose
Tolerance Test (GTT)

• An appointment is required for this test. To book, call your preferred collection centre. Visit our Locations pages to find the nearest centre.
• Patients in WA only: If you are unable to reach your selected collection centre by phone, please email gtt.wa@clinicallabs.com.au to begin the appointment booking process.
• You are to remain on a normal, unrestricted diet for at least 3 days prior to the test.
• You have had no significant illness for 2 weeks prior to the test.
• Fasting is required. Do not eat or drink for 10-12 hours prior to your blood test.
• Drinking water before your procedure is permitted and may help reduce the risk of fainting, as well as make it easier for the collector to locate your veins.
• Medications should only be stopped on the instructions of your doctor. Take them with water only.
• Due to the nature of the test, testing is generally done in the morning.
• Maintain normal activity prior to the test.
• Avoid smoking for 2 hours before and during the test.
• Before drinking the glucose, please inform the collection staff if you have any allergies.

Note: If you are prone to fainting, please inform the collector before the procedure.

• Collection of a fasting blood sample.
• Drinking a 75g bottle of glucose within 5 minutes.
• Collection of a blood sample 1 hour after consuming glucose.
• Collection of a blood sample 2 hours after consuming glucose.

• You must remain seated quietly during the test.
• You will be at the collection centre for a minimum of 2 hours.
• You are required to remain in the collection centre until the procedure is completed.
• Bring some reading material or other activity to pass the time.
• If you feel unwell during the test, please inform the collection staff, as you may wish to lie
  down.

Note: If insulin levels are requested along with the GTT, the collection staff will draw blood for this in a separate tube, at the same time that each glucose blood sample is collected.

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