Need dose increase.Gastric disturbance may be due to high sugars

common side effects of metformin are as follows :- Abdominal or stomach discomfort cough or hoarseness decreased appetite diarrhea fast or shallow breathing fever or chills general feeling of discomfort lower back or side pain muscle pain or cramping painful or difficult urination sleepiness Get cbc and renal function done,as sometimes ongoing renal diease may also cause similar symptoms.sometimes severe metabolic acidosis also occurs.