Metformin
Metformin is an oral drug used primarily to treat type II diabetes. It can be used in combination with other drugs, and cannot treat type 1 diabetes. The derivative of Metformin is a plant called Galega officinalis, which is a French lilac. In medieval Europe, this plant was thought to have had herbal benefits, containing guanidine which showed hypoglycaemic properties. Unfortunately, it was too toxic to use as a treatment[1].
Metformin works primarily by reducing hepatic gluconeogensis, ultimately lowering blood/sugar levels and preventing hyperglycemia[2].
Metformin has also shown to inhibit the growth of pancreatic cancer by disrupting crosstalk between G protein-coupled receptors and insulin receptor signalling systems in the pancreas[3].
You should not take metformin if you have any history of liver or heart disease.
References