How long does it take for glyburide to become effective?

Varies (1 - 2 hours) Depending on the formulation ingested (micronized (glynase) or conventional Glyburide (diabeta, micronase)) onset of action ranges from about 1 to 2 hours with a maximum reduction of blood sugar seen within 3-4 hours. May last in body for over 18 to 24 hours. Should be taken with breakfast or main meal of the day to help reduce symptoms of low blood sugar (tremors, sweating, irritable, fatigue).