On being diagnosed diabetic I was prescribed Metformin which helped me to lose weight at 1lb a month I was so pleased to lose two and half stone over 2/3 years. However my medication was changed to a slow release metformin since when I have GAINED weight at a rate of about one pound a month. there has been no change other than that of slow release metformin. Has anyone had the same experience. G.P and diabetic nurse say changing to the slow release medication would not cause weight gain.