The most common glucose tolerance test is the oral glucose tolerance test (OGTT ). Before the test begins, a sample of blood will be taken. The test should not be done during an illness, as results may not Usually the OGTT is performed in the morning as glucose. PREPARATION FOR THE ORAL GLUCOSE. TOLERANCE TEST (oGTT). Practice stamp: Your appointment for the oGTT: A further test* is recommended for all.
Oral glucose tolerance test preparation Video