Biguanides

These reduce the amount of sugar made in the liver.

Sulfonylureas

These stimulate the beta cells in the pancreas to make more insulin. They are either short- or long-acting.

Meglitinides

These stimulate the beta cells in the pancreas to make more insulin. They work quickly. But they wear off quickly too.

Thiazolidinediones

These help insulin work better in the muscle and fat. They also reduce the amount of sugar made in the liver.

Alpha-glucosidase inhibitors

These block the enzymes that digest starches. They also help slow the breakdown of some sugars. This stops blood sugar from rising quickly after you eat.

DPP-IV inhibitors

These boost the body's own ability to lower blood sugar. They do this by blocking an enzyme called DPP-IV (dipeptidyl peptidase).

SGLT2 inhibitors 

These block the kidney's ability to reabsorb sugar from the blood. Extra sugar is passed in your urine.

Bile acid sequestrants 

These are often used to lower cholesterol. But they also lower blood sugar.

Dopamine-2 agonists

Experts think these medicines help the body's cells respond better to insulin.

GLP-1 receptor agonists

Although usually taken as an injection, this type of medicine is now available in pill form. These medicines increase the amount of insulin your body releases with meals. Some of these have also been shown to help with weight loss.