Metformin is an efficient medicine used for the treatment of type 2 diabetes. This drug is not going to work for type 1 diabetes and is not supposed to be taken for that condition. Metformin is usually taken two or three times a day - everything depends on your individual needs that will be assessed by your health care provider. Make sure you tell your doctor if you have any medical conditions that may require a dose adjustment. It's also very important that you take the right amount of metformin and avoid using too much of it. The following symptoms are possible if you take too much of metformin: decreased appetite, extreme tiredness, vomiting, discomfort, stomach pain, weakness, lightheadedness, dizziness, nausea, and muscle pain. In case of an overdose make sure you seek emergency medical help and avoid using more of metformin in the meantime. If you are currently taking any HIV/AIDS meds, nitrates, angiotensin converting enzyme (ACE) inhibitors, propranolol, acetaminophen, aminoglycoside antibiotics, rifampin, other nonsteroidal anti-inflammatory drugs, acyclovir, lithium, sulfa antibiotics, cyclosporine, cancer chemotherapy medications, or gold compounds - let your doctor know, as interactions as possible.