Hi, thanks for asking in Healthcare Magic, GMET 850 or Metformin is given in Poly Cystic Ovarian Disease (PCOD). In PCOD there is insulin resistance. Insulin increases the utilization of glucose by peripheral tissues. Lack of insulin action results in increase in blood sugar levels (Diabetes). Insulin resistance means improper insulin action. Metformin is an insulin sensitiser ie., it improves insulin action. Abdominal pain, anorexia, nausea, metallic taste, mild diarrhea, weight loss and weakness are frequent side effects of Metformin. It can also result in chest discomfort, flushing and palpitation, all of which you feel as breathing problem. Lactic acidosis is a serious side effect of Metformin. Most people tolerate Metformin but in some, these troublesome side effects will necessitate discontinuation of the drug. Sustained release preparation of Metformin are available. This tablet releases Metformin slowly and so do not cause these unwanted side effects.Pioglitazone, another insulin sensitizer can be used as an alternative to Metformin in PCOD. It also reduces insulin resistance in PCOD. Both drugs has similar efficacy. You can either take sustained release preparation of Metformin or you can switch over to the alternative drug Pioglitazone. I hope this is useful.