Maybe I am being your typically over-worried mother here, but I am wondering if there are any concerns about being on Metformin when you have the flu. My 20 year-old daughter has been on Metformin for PCOS for two years. She is showing symptoms of the flu, and to make it harder on me, she's on an internship in Florida, so I can't even "see" the symptoms. She tells me she has fever, headache, sore throat, dizziness, vomiting, and general achiness.