The best way to lose weight is through proper diet and regular exercise. There are no shortcuts to a good and healthy body. If your doctor has suggested Glucophage based on your blood tests,you can obviously take it. But if she hasn't and you are thinking of taking this medication on your own,then my suggestion would be that "don't do it". There may be side-effects and unsupervised use is never recommended.
Next Steps
Look at your diet closely. Do you overeat or skip meals instead?? Both are harmful. Visit a nutritionist and get a healthy diet chart. And also start exercising. You can even start at home with freehand exercises,if you don't have time to hit the gym.
Health Tips
Results will take time. But you need to be patient. There won't be miracles. But your hardwork will definitely show. So gear up and start from tomorrow itself!