Here is my understanding about glucophage and a bit of personal experience here.
I started glucophage before I started LC, I have had PCOS for years and frankly I was tired of NO help what so ever. IT seemed I was getting sicker and could find nothing to help. I had been on BCP for many years and right now I'm still afraid to stop them because I have a tendency to get endometrial hyperplasia when I'm not on them. To not treat it, would lead to cancer. I went to a new doctor he saw that I wanted to take my care in my control and suggested that I start glucophage and aldactone as both seem to help with PCOS. I can say that the glucophage helped greatly. I rarely shake anymore, I feel good. My insulin level is stable.
I would suggest to have an insulin level done. If it is high, take the glucophage, if it is not, you can decide what to do from there. Glucophage acts on the cells allowing them to not be so resistant, and it also does not effect insulin production. If you are low carbing you should not find that you get "resistant" to the medication. IT is not like an antibiotic, antibiotics effect an organism the infects the body, it is that organism that becomes reisitant to fight it's own destruction. IF you continue to eat high carb, eventually the cells will start to become more resistant and then the effect of glucophage will decrease. I have watched my mother in-law over the years get sicker and sicker, to the point she now needs insulin. can the side effects of the meds damage your system yes, but I honestly think it is the diet in this case. We are so off on what we are suppose to eat that the drugs can't work the way they should. On a low carb diet you should be able to get off the glucophage in a couple of years, if not within a year.
Tanya