There isn’t a clear-cut answer, so discuss it with your doctor. Each tablet contains a precise dosage of glucose (4 grams.) The ADA recommends that a person take approximately 15g of glucose if there is a lowering in blood sugar. If your blood sugar level is 2.8 mmol/L (50mg) or less, increase the dose to 20g. If after 15 minutes, the levels don’t balance out, repeat the process.