When it comes to metformin, you will be no stranger to it, it is one of the most classic glucose-lowering drugs and has an irreplaceable role in the treatment of diabetes. It is not only the preferred oral hypoglycemic agent for many type 2 diabetes patients, but also the only oral hypoglycemic agent available for children with type 2 diabetes …… And, lowering sugar doesn’t seem to be all that it is capable of. Reports show that metformin has preventive effects on many cancers, including lung, stomach, pancreatic, breast, ovarian and colorectal cancers, and recently, it has been found to have preventive effects on liver cancer, raising expectations.