I have been prediabetic for several years and last October my hba1c level went to 49 and treatment initially was to be diet and exercise. This hasn't worked and my hba1c level has been creeping up until it reached 53 two months ago. I was prescribed metformin initially 500mg to be increased to 1000mg after a week. I had the usual side effects of upset stomach and tiredness initially which passed after two weeks so I increased dosage to 1000mg. The side effects were worse including severe nausea and acid reflux and fatigue and constipation and other problems. I perservered for three weeks and finally spoke to the Diabetic nurse on Monday who had no hesitation in changing to slow release of 500mg twice a day. Started Tuesday and felt really ill yesterday. My question is would I be better taking one dose of 1000mg at night as the prescription leaflet suggests.