question: Yes i just started glyburide due to gestational diabetes because the metformin was not bringing down my fast numbers as they are the ones that I m struggling with. Also metformin gave me stomach problems. I just want to know how fast does glyburide take effect and how long does it last ? My Dr has me taking 1.5 in the morning with breakfast and 2 5 with dinner. It s been a week now and I ve only seen one normal fast. I think im taking the pill too early at night and maybe it wears off before I wake. Im thinking to take anotger 1.5mg at 4am since i wake at 7am and take my blood sugar. What do you think?