Oral Medications for Type 2 Diabetes: Types and How They Work

There are several oral medications for type 2 diabetes, and each works differently to lower blood sugar. Some reduce glucose production in the liver, some improve insulin sensitivity, and others help your body release insulin or remove excess glucose.

The right medication depends on your A1C, heart and kidney health, weight goals, risk of low blood sugar, side effects, cost, and other health factors. ¹

Key Takeaways

• Oral diabetes medications lower blood sugar in different ways.
• Metformin reduces glucose production by the liver and improves insulin sensitivity.
• SGLT2 inhibitors can provide heart and kidney benefits for some people.
• Sulfonylureas and meglitinides can cause low blood sugar.
• Most GLP-1 medications are injected, but semaglutide is also available as an oral medication.
• Medication choice should consider heart and kidney health, weight, hypoglycemia risk, side effects, cost, and personal preferences.¹

How Do Oral Diabetes Medications Work?

Type 2 diabetes occurs when the body becomes resistant to insulin and may gradually lose some of its ability to produce enough insulin.

Oral medications can help by:

• Reducing glucose production in the liver
• Improving insulin sensitivity
• Increasing insulin release
• Slowing carbohydrate digestion
• Reducing glucagon activity
• Helping the kidneys remove excess glucose

Because different medications target different problems, more than one may be used at the same time.²

Common Oral Medications for Type 2 Diabetes

Metformin

Metformin is a biguanide and one of the most commonly used type 2 diabetes medications.

It primarily lowers blood sugar by reducing glucose production in the liver and helping the body use insulin more effectively.²

Metformin generally has a low risk of causing hypoglycemia when used alone and is usually weight neutral or associated with modest weight loss.

Common side effects include nausea, diarrhea, and stomach discomfort. Long-term use may also contribute to vitamin B12 deficiency.¹

SGLT2 Inhibitors

Sodium-glucose cotransporter 2 (SGLT2) inhibitors lower blood sugar by helping the kidneys remove glucose through urine.

Examples include:

• Empagliflozin
• Dapagliflozin
• Canagliflozin
• Bexagliflozin

Certain SGLT2 inhibitors also provide important benefits for people with heart failure, cardiovascular disease, or chronic kidney disease.¹

Potential side effects include genital yeast infections and dehydration. A rare but serious risk is diabetic ketoacidosis (DKA).¹

DPP-4 Inhibitors

DPP-4 inhibitors allow natural incretin hormones to remain active longer. These hormones help increase insulin release when blood sugar is elevated and reduce glucagon.

Examples include:

• Sitagliptin
• Linagliptin
• Saxagliptin
• Alogliptin

These medications are generally weight neutral and have a relatively low risk of hypoglycemia when used alone.¹

Sulfonylureas

Sulfonylureas stimulate the pancreas to release more insulin.

Examples include:

• Glipizide
• Glimepiride
• Glyburide

They can lower blood sugar effectively and are relatively inexpensive, but they can cause hypoglycemia and weight gain.¹

Anyone taking type 2 diabetes medications that increases insulin release should know how to recognize the symptoms of high and low blood sugar.

Thiazolidinediones (TZDs)

Thiazolidinediones, or TZDs, make the body’s tissues more sensitive to insulin.

Pioglitazone is a commonly used medication in this class.

TZDs can lower blood sugar without a high risk of hypoglycemia when used alone, but they may cause weight gain and fluid retention and can worsen heart failure in some people.¹

Meglitinides

Meglitinides stimulate the pancreas to release insulin around meals.

Examples include:

• Repaglinide
• Nateglinide

They act quickly and can help control after-meal blood sugar, but they can cause hypoglycemia and weight gain.¹

Alpha-Glucosidase Inhibitors

Alpha-glucosidase inhibitors slow carbohydrate digestion in the intestine, helping reduce the rise in blood sugar after meals.

Examples include:

• Acarbose
• Miglitol

Gas, bloating, and diarrhea are common side effects.

Oral GLP-1 Medication

GLP-1 receptor agonists help increase insulin release when blood sugar is elevated, reduce glucagon, slow stomach emptying, and decrease appetite.

Most GLP-1 medications are injected, but semaglutide is also available as an oral medication.¹

This should not be confused with Ozempic, which is an injectable form of semaglutide. Learn more in our guide to Ozempic safety for people with and without diabetes.

GLP-1 medications can substantially lower blood sugar and support weight loss, although gastrointestinal side effects are common.¹

Less Common Oral Medications

Other oral options include colesevelam, a bile acid sequestrant, and bromocriptine, a dopamine-2 agonist.

These medications are used less commonly than options such as metformin, SGLT2 inhibitors, DPP-4 inhibitors, and GLP-1 therapies.

Which Type 2 Diabetes Medication Is Best?

There is no single best medication for everyone.

Healthcare providers may consider:

• A1C and blood sugar levels
• Cardiovascular disease
• Heart failure
• Kidney disease
• Weight goals
• Hypoglycemia risk
• Side effects
• Kidney and liver function
• Medication cost and access
• Personal preferences

If you’re monitoring longer-term glucose control, our A1C Calculator can convert an A1C result into estimated average glucose (eAG).

For people with certain heart or kidney conditions, an SGLT2 inhibitor or GLP-1 receptor agonist with proven cardiovascular or kidney benefits may be recommended even if additional glucose lowering is not the primary concern.¹

Combination therapy may also be started early when it can help a person reach individualized treatment goals more effectively.¹

Some people with type 2 diabetes may eventually need insulin in addition to or instead of oral medication as their treatment needs change.

Side Effects of Oral Diabetes Medications

Side effects vary among different oral diabetes medications and may include:

• Low blood sugar
• Nausea or diarrhea
• Genital infections
• Dehydration
• Weight gain or weight loss
• Fluid retention
• Vitamin deficiencies
• Drug interactions

Blood sugar targets vary by individual. Our blood sugar charts provide general reference ranges for fasting and after-meal glucose.

Kidney function can also affect which medications are appropriate and how they are dosed.

Do not start, stop, or change a diabetes medication without discussing it with your healthcare provider.

When to Call Your Healthcare Provider

Contact your healthcare provider if your blood sugar remains consistently outside your target range, you experience repeated hypoglycemia, or medication side effects become difficult to manage.

Seek urgent medical care for severe hypoglycemia, loss of consciousness, persistent vomiting, difficulty breathing, confusion, or possible symptoms of diabetic ketoacidosis.

Frequently Asked Questions About Oral Type 2 Diabetes Medications

Bottom Line

There are many oral medications for type 2 diabetes, and each has different benefits, risks, and effects on blood sugar.

Metformin remains an important option, while SGLT2 inhibitors, DPP-4 inhibitors, oral GLP-1 therapy, sulfonylureas, and other medications may be appropriate depending on individual needs.

The best treatment considers not only A1C but also heart health, kidney health, weight, hypoglycemia risk, side effects, cost, and personal preferences.¹

References

1. American Diabetes Association Professional Practice Committee. Pharmacologic Approaches to Glycemic Treatment: Standards of Care in Diabetes—2026. Diabetes Care. 2026;49(Supplement 1). [↩] [↩] [↩] [↩] [↩] [↩] [↩] [↩] [↩] [↩] [↩] [↩] [↩] [↩] [↩] [↩] [↩]
2. National Institute of Diabetes and Digestive and Kidney Diseases. Insulin, Medicines, & Other Diabetes Treatments. [↩] [↩]