Type 2 Diabetes Medicines Explained

5 min readType 2 Diabetes BasicsPart 8 of 18

In brief

Type 2 diabetes affects several organs, so different medicines work in different ways: on the liver, gut, pancreas, kidneys, muscles and brain.
Choice depends on more than blood sugar. Heart disease, kidney disease, weight, risk of lows, cost and personal preference all matter.
Needing medicine, or more of it over time, is not a failure. It reflects how type 2 diabetes naturally changes.

A generation ago, there were only a few diabetes medicines. Today there are around a dozen classes, and some protect the heart and kidneys as well as lowering blood sugar. That choice is good news, but it can be confusing. This guide explains the main types in plain language. It uses generic (non-brand) names and is not a substitute for advice from your own prescriber or pharmacist.

Where the medicines act

Each medicine type targets a different part of the problem

Liver

Metformin and pioglitazone reduce the extra sugar the liver releases.

Pancreas

GLP-1 medicines, DPP-4 inhibitors and sulfonylureas increase insulin release.

Kidneys

SGLT2 inhibitors let the kidneys pass extra sugar out in the urine.

Gut and brain

GLP-1 medicines slow stomach emptying and increase fullness.

Muscle and fat

Pioglitazone and exercise make cells more sensitive to insulin.

Whole body

Insulin directly replaces what the pancreas can no longer make.

The main medicine types

Type (examples)	How it works	Main benefits	Watch for
Metformin	Reduces sugar released by the liver	Long track record, low cost, no lows on its own, weight neutral	Stomach upset (take with food; extended-release helps); vitamin B12 levels over time
SGLT2 inhibitors (empagliflozin, dapagliflozin, canagliflozin)	Kidneys remove extra glucose in urine	Protect against heart failure and kidney decline; modest weight loss	Genital yeast infections; dehydration; rare ketoacidosis, especially when ill or fasting
GLP-1 receptor agonists (semaglutide, dulaglutide, liraglutide) and dual GIP/GLP-1 (tirzepatide)	Boost insulin when glucose is high, lower glucagon, slow digestion, reduce appetite	Strong A1C and weight reduction; several lower heart attack and stroke risk	Nausea and other stomach effects, usually early; mostly injections (one tablet form)
DPP-4 inhibitors (sitagliptin, linagliptin)	Prolong the body’s own incretin hormones	Tablet; well tolerated; no lows on their own	Modest effect; rare joint pain or pancreatitis
Sulfonylureas (gliclazide, glipizide, glimepiride)	Push the pancreas to release more insulin	Effective, fast-acting and inexpensive	Low blood sugar (hypoglycemia) and weight gain
Pioglitazone	Improves insulin sensitivity in muscle, fat and liver	Durable effect; helps fatty liver	Weight gain, fluid retention (avoid with heart failure), bone fractures
Insulin (long-acting basal, mealtime, premixed)	Replaces missing insulin	Most powerful; dose can be adjusted to any level	Low blood sugar, weight gain; needs monitoring and training

Your prescriber weighs your heart, kidney and weight goals, not just your A1C.

How doctors choose

Current guidelines from the American Diabetes Association and European Association for the Study of Diabetes ask a series of questions:

Choosing a medicine: the key questions

Heart or kidney disease?Prefer an SGLT2 inhibitor and/or a GLP-1 with proven benefit

Weight goals?GLP-1 or dual GIP/GLP-1 medicines help most

How far from target?Higher A1C may need combination therapy or insulin

Cost and preferenceTablet or injection, budget, side effects

Metformin is still a common first choice because it is effective, safe and affordable. But for people with heart disease, heart failure or chronic kidney disease, an SGLT2 inhibitor or GLP-1 medicine is now recommended from the start, whatever the A1C, because they lower the risk of serious events. Many people take two or three medicines together, often combined in a single tablet.

What about insulin?

Many people fear insulin, often because a relative started it late in their illness. In fact, insulin is simply a hormone the body is short of. It is needed when blood sugar is very high at diagnosis, during illness or pregnancy, or when other medicines are no longer enough. Modern pens have very fine needles, and many people start with just one injection of long-acting insulin a day. See When Your Type 2 Diabetes Changes.

Safety tips for any diabetes medicine

If you take insulin or a sulfonylurea, learn the signs and treatment of low blood sugar, and carry fast-acting glucose.
If you are unwell and cannot eat or drink normally, ask your care team about “sick day rules”. Some medicines (such as metformin and SGLT2 inhibitors) may need to be paused.
Tell every doctor, dentist and pharmacist what you take, including supplements.
Never stop or change a medicine without talking to your prescriber.

Common questions

Will I have to take diabetes medicine forever?

Many people do take medicine long term, because type 2 diabetes tends to progress. But some people, particularly those who lose a lot of weight early on, can reduce or stop medicines under medical supervision. See our article on when diabetes changes.

Can I take metformin if I have kidney problems?

Metformin can usually be used with mild to moderate kidney disease, sometimes at a lower dose. It is generally stopped when kidney function is severely reduced. Your doctor will check your eGFR at least yearly to decide.

Are brand-name medicines better than generics?

Approved generic medicines contain the same active ingredient and must meet the same quality standards. They are usually much cheaper. Many diabetes medicines, including metformin, most sulfonylureas, pioglitazone and several DPP-4 inhibitors and SGLT2 inhibitors in some countries, are available as generics.

Key takeaways

Different medicines act on the liver, pancreas, kidneys, gut and muscle.
SGLT2 inhibitors and GLP-1 medicines can protect the heart and kidneys.
The right plan balances blood sugar, organ protection, weight, lows, cost and preference.
Next: GLP-1 medicines: how they work and what to expect.

Type 2 Diabetes Basics: all 18 articles

Sources

Davies MJ, Aroda VR, Collins BS, et al. Management of hyperglycemia in type 2 diabetes, 2022. A consensus report by the ADA and the EASD. Diabetes Care. 2022;45(11):2753–2786.
American Diabetes Association Professional Practice Committee. 9. Pharmacologic Approaches to Glycemic Treatment: Standards of Care in Diabetes—2026. Diabetes Care. 2026;49(Suppl 1).
National Institute of Diabetes and Digestive and Kidney Diseases. Insulin, Medicines, & Other Diabetes Treatments.
Zinman B, et al. Empagliflozin, cardiovascular outcomes, and mortality in type 2 diabetes (EMPA-REG OUTCOME). N Engl J Med. 2015;373:2117–2128.
Marso SP, et al. Liraglutide and cardiovascular outcomes in type 2 diabetes (LEADER). N Engl J Med. 2016;375:311–322.

This article is for general education and is not a substitute for advice from your own doctor, diabetes educator or pharmacist.

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