Been on Metformin 8 years, one 500mg after breakfast, lunch & supper (3 daily), it works quite well for me, my blood glucose worsens noticeably & quite quickly (within 48 hours or less) if I stop taking it (I've experimented). Now my fasting blood glucose is worsening, so am trying fasting once a week for 24 or 36 hours. Anyone care to say if I should take the 3 Metformin a day on the fasting days? Thank you.