The 9 Types Of Oral Diabetes Medications: Pros, Cons, and How They Work

Diabetes medications continue to improve, and for those with type 2 diabetes, it’s no longer a matter of just Metformin or insulin. With a growing variety of diabetes medications, each of which combats diabetes in a different way, it’s possible to change medications after one is no longer effective or be prescribed a combination pill that mixes two different medications for more effective treatment.

For those diagnosed with type 2 diabetes, changes in exercise and diet habits may be the first prescription for combating high blood sugar, but there are also 8, or perhaps 9, oral medications available to help people with type 2 win the A1C game. Here’s a quick explanation of each of the types, how they work, and their pros and cons:

Photo: AdobeStock/Monticello
Photo: AdobeStock/Monticello

1. Biguanides

How They Work:

Biguanides decrease the amount of glucose produced by the liver. Metformin, the only biguanide available in most of the world, also makes muscles more sensitive to insulin so that glucose is more readily absorbed.

How They’re Taken

Once or twice daily (usually twice) with a meal.


Biguanides are convenient and effective. Side effects might include loss of appetite, weight loss, diarrhea, nausea, vomiting, upset stomach, weakness, or a metallic taste in the mouth. For patients with kidney or liver dysfunction, biguanides may post a risk of lactic acidosis.


Metformin (Glucophage XR, Fortamet, Glumetza).

Photo: AdobeStock/Sherry Young
Photo: AdobeStock/Sherry Young

Article continues below

Our Featured Programs

See how we’re making a difference for People, Pets, and the Planet and how you can get involved!

2. Sulphonylureas

How They Works:

Sulfonylureas work by telling your beta cells to release more insulin. They stimulate insulin release right after a meal as well as for the next few hours. Sulphonylureas are often taken in combination with Metformin.

How They’re Taken:

Taken with food once or twice daily.


Sulphonylureas are convenient to take and generally result in a 1 to 2 percentage point reduction in A1C. Side effects might include hypoglycemia, weight gain, upset stomach, sensitivity to light, and allergic skin reactions. Other side effects are rare.


Glimepiride, Glyburide, Glipizide, and Micronized glyburide (Amaryl, Diabeta, Micronase, Glucotrol, Glucotrol XL, and Glynase).

Photo: AdobeStock/JJAVA
Photo: AdobeStock/JJAVA

“NEXT” for more medications

Support Research

Fund Diabetes research and care at The Diabetes Site for free!