hello i,ve been taking metformin for 4 years with out any problems, till about 2 months ago im sick after i take them, im on 4 tablets 500mg a day i cut down to one a day but still ill .i stop taking them a week now and im feeling better feeling better ,i can,t take anymore of them i don,t know what is happening ,i made a apointment for my GP ,any body any idea,s what it could be, there the slow release 500mg tabs 2 twice a day after foot.