Is my doctor being cautious? My recent labs: non fasting glucose was154 and AC1 was 6.5. He put me on metformin 250mg. Side-affects were severe headache,nausea, chest pain, stomach cramps, watery stools and insommia(34 hrs). Next he tried 1/2 pill evey other day and I have the same side affects only insommia is 20 hours and counting.