Oral Glucose Tolerance Test

The oral glucose tolerance test (OGTT) measures how well your body is able to break down glucose, or sugar. First, a blood sample will be collected, providing a baseline for comparing other glucose values. You will then be asked to quickly drink between 75 and 100 grams of a sweet liquid containing a measured amount of glucose. Blood samples will be collected at timed intervals of 1, 2, and sometimes 3 hours after you drink the glucose.