I’ve taken Metformin since diagnosis nearly a year ago. I started on one 500mg per day and increased one tablet per week til I reached three per day. I agree with
@Freema that the reduction from Metformin appeared to be about 1mmol, which is significant if you’re near the limit. I also have benefitted from the appetite suppression gained from it, I don’t know if you’ve noticed any effect on your appetite but I know you’re looking to loose weight so that’s something to consider. Although I’m looking to reduce my Metformin at my next review in the summer I am quite comfortable staying on a smaller dose for its other benefits. A fortnight isn’t long to wait to discuss this with your GP, I’d be inclined to talk to them first before making a decision. Have a read of this before you decide too:
http://www.lifeextension.com/magazine/2001/9/report_metformin/Page-01