Biguanides are a group of oral antidiabetic agents that can be used along with exercise and diet to treat type 2 diabetes. They lower glucose (blood sugar) in the body by ensuring the liver does not make too much glucose. They also slow the absorption of glucose from food in the small intestine and increase the sensitivity of muscle tissue to insulin, a hormone that allows glucose from the bloodstream into the cells.

Biguanides can also help lower levels of blood fats (lipids) such as triglycerides and cholesterol. They may help patients lose weight by promoting feelings of fullness after meals.

Another potential benefit is that biguanides may help prevent diseases of the large blood vessels such as atherosclerosis. In addition, they are being studied as a treatment for polycystic ovarian syndrome, a female endocrine disorder.

Biguanides are not recommended for people with certain complications, including kidney disease.

The only biguanide approved by the U.S. Food and Drug Administration is metformin. It is one of the few diabetes drugs cleared for use by children. Metformin is also available in several combination drugs.