Good writeup on the work being done to research the anti-aging effects of metformin:
Includes a nice discussion, towards the end, of the mechanism by which metformin may work, namely by reducing the amount of glucose produced by the liver, and in turn, the amount of insulin produced by the pancreas.
If nothing else, it’s very encouraging that there are researchers working on this, because even if it turns out that metformin is less miraculous than hoped, more research that touches on the role of insulin in aging and chronic disease should hopefully bear fruit regardless.