Types of Diabetes Medication: An Educational Overview

Reviewed for accuracy against named public sources. Educational content only — see our Medical Disclaimer.

This is a general educational overview of the major classes of diabetes medication and how they broadly work in the body. It is not guidance on which medication is right for you, and it includes no dosing information — that's a decision for you and your prescribing doctor.

Metformin

Often a first-line medication for type 2 diabetes, metformin primarily works by reducing how much glucose the liver releases and improving the body's sensitivity to insulin.

Sulfonylureas

This class works by stimulating the pancreas to release more insulin. They've been used for decades and are generally taken by mouth.

SGLT2 inhibitors

These medications work in the kidneys, causing excess glucose to be excreted in urine rather than reabsorbed into the bloodstream. Some medications in this class have also shown cardiovascular and kidney benefits in research beyond blood sugar control.

GLP-1 receptor agonists

This class mimics a naturally occurring hormone that increases insulin release, slows digestion, and reduces appetite. Some are taken by injection and some in pill form, depending on the specific medication.

DPP-4 inhibitors

These work by extending the activity of naturally occurring hormones that help regulate blood sugar after meals, generally with a modest effect compared to some other classes.

Insulin

Insulin therapy replaces or supplements the body's own insulin production and comes in several types that differ mainly in how quickly they act and how long their effect lasts. Insulin is required for everyone with type 1 diabetes and is used by many people with type 2 diabetes as well, often alongside other medications.

This is general education, not a treatment plan

Medication choice depends on many individual factors — other health conditions, cost, side effect profile, and personal preference among them — and should always be decided with your prescribing doctor. This site does not calculate or suggest doses for any medication, including insulin.

Once you have a treatment plan in place, our A1C to eAG converter can help you understand how a lab result translates into an average glucose figure.

How doctors choose between classes

Medication choice typically weighs several factors together: how effectively a class is expected to work for the individual, other health conditions (some classes have added benefits for heart or kidney health), side effect profiles, cost and insurance coverage, and personal preference around how a medication is taken. There's rarely a single "best" choice independent of the person taking it.

Combination therapy

It's common for type 2 diabetes treatment to eventually involve more than one medication class working together, especially if a single medication isn't sufficiently managing blood sugar on its own. This is a normal part of how diabetes treatment often evolves over time and isn't a sign of failure — it reflects the condition's tendency to progress and treatment being adjusted accordingly.

Sources

NIDDK: Insulin, Medicines, & Other Diabetes Treatments · American Diabetes Association: Medications