Indications  
 
   
     
 
Metformin
Biguanide
Indications
Interactions
Formulations
Mechanism of action
Adverse effects
Clinical pharmacology
Overdosage
The main use for metformin is in the treatment of diabetes mellitus type 2, especially when this accompanies obesity and insulin resistance. Metformin is the only anti-diabetic drug that has been proven to reduce the cardiovascular complications of diabetes, as shown in a large study of overweight patients with diabetes. Unlike the other most-commonly prescribed class of oral diabetes drugs, the sulfonylureas, metformin (taken alone) does not induce hypoglycemia. Hypoglycemia during intense exercise has been documented, but is extremely rare. It also does not cause weight gain, and may indeed produce minor weight loss. Metformin also modestly reduces LDL and triglyceride levels.

It is also being used increasingly in polycystic ovarian syndrome (PCOS), non-alcoholic fatty liver disease (NAFLD) and premature puberty, three other diseases that feature insulin resistance; these indications are still considered experimental. Although metformin is not licenced for use in PCOS, the United Kingdom's National Institute for Health and Clinical Excellence recommends that women with PCOS and a body mass index above 25 be given metformin when other therapy has failed to produce results. The benefit of metformin in NAFLD has not been extensively studied and may be only temporary.