SGLT2 inhibitors: how they work and the drug class

Key takeaways

• SGLT2 inhibitors are a drug class nicknamed the gliflozins. The FDA-approved members are canagliflozin (Invokana), dapagliflozin (Farxiga), empagliflozin (Jardiance), ertugliflozin (Steglatro), and bexagliflozin (Brenzavvy) .
• The mechanism is one idea. SGLT2 sits in the kidney and pulls most of your filtered glucose back into the blood; these drugs block it, so the sugar leaves in your urine instead .
• As a blood-sugar drug the effect is modest, roughly a 0.5% to 1.0% drop in HbA1c, plus a little weight and blood-pressure reduction .
• The bigger deal is the organ protection. Dapagliflozin and empagliflozin cut heart-failure outcomes regardless of ejection fraction, and the class slows chronic kidney disease whether or not you have diabetes .
• The side effects to know are genital yeast infections, a rare ketoacidosis that can happen at near-normal blood sugar, dehydration, and, mostly with canagliflozin, a raised amputation signal in one trial program .

The gliflozin decoder: every -gliflozin and what it is for

One name to keep separate: sotagliflozin (Inpefa) is a cousin, not a pure SGLT2 drug. It blocks both SGLT2 in the kidney and SGLT1 in the gut, so it is a dual inhibitor .

How they work: your kidney recycles sugar, these pills stop it

Your kidneys filter a lot of glucose out of your blood every day, then quietly reabsorb almost all of it so you do not waste it. The protein doing most of that reabsorbing, in the early part of the kidney's plumbing, is SGLT2 .

An SGLT2 inhibitor jams that recycler. Block SGLT2 and the kidney stops clawing back so much sugar, the threshold at which glucose spills into the urine drops, and the extra glucose simply leaves your body when you pee . Across the class, that cuts glucose reabsorption by roughly 30% to 60% .

That is the answer to the most-Googled version of this question. Canagliflozin's mechanism of action, in the label's own framing, is that it inhibits SGLT2, reduces reabsorption of filtered glucose, lowers the renal threshold for glucose, and increases urinary glucose excretion . Dapagliflozin's drug classification is the same: it is a sodium-glucose cotransporter 2 (SGLT2) inhibitor .

How a sugar pill became a heart and kidney drug

This is the part that surprised cardiologists too. SGLT2 inhibitors were built to lower blood sugar, and as glucose drugs they are unremarkable, about a 0.5% to 1.0% HbA1c reduction . The outcome trials are where they earned their reputation.

Dapagliflozin and empagliflozin were shown to reduce cardiovascular death and heart-failure hospitalizations in people with heart failure, and the benefit held regardless of ejection fraction, meaning both the weak-pump and stiff-pump types . Farxiga's label now leads with exactly those heart and kidney uses .

The kidney story is similar. The class slows the decline of chronic kidney disease and lowers the chance of progressing to kidney failure, and that protection shows up whether or not the person has type 2 diabetes . That is why you now see these drugs prescribed by heart and kidney specialists, not just for diabetes .

The side effects worth knowing about

Pushing sugar into the urine has predictable downstream effects, and a couple of rarer ones that matter. None of this is meant to scare you off a drug your clinician recommended; it is what to watch for and ask about.

• Genital yeast infections are the classic one. Sugary urine feeds yeast, so genital mycotic infections are a common side effect .
• Euglycemic diabetic ketoacidosis is the rare-but-serious one. These drugs roughly triple the risk of ketoacidosis, and it can occur with blood glucose under 250 mg/dL, so it is easy to miss .
• Dehydration and low blood pressure can happen because you are losing fluid, which sometimes stresses the kidneys short term .
• Fournier gangrene, a severe genital-area infection, is rare but a known class warning .
• An amputation signal showed up specifically with canagliflozin in the CANVAS trials (about 5.9 versus 2.8 amputations per 1,000 patient-years), mostly toes and feet .

These are prescription drugs, and the dosing reflects how your kidneys are doing. Canagliflozin starts at 100 mg once daily before the first meal and can go to 300 mg ; dapagliflozin is typically 10 mg once daily, with a 5 mg starting option when it is used just for blood sugar . Below certain kidney-function cutoffs the glucose-lowering effect fades, which is why the labels stop recommending them for sugar control in advanced kidney impairment .

SGLT2 inhibitors versus GLP-1s: different tools, often used together

If you follow GLP-1 drugs like semaglutide or tirzepatide, it is worth knowing these are a separate class with a separate job. GLP-1s act on appetite and the gut to drive larger weight loss; SGLT2 inhibitors are pills that work at the kidney, lose you sugar, and shine at heart and kidney protection .

They are not rivals. They run on completely different mechanisms, so they can sit alongside each other rather than as an either-or choice. If you want the GLP-1 side of the cardiometabolic picture, GLP-1s and cardiovascular outcomes and the newer GLP-1 indications cover it.

The honest read

SGLT2 inhibitors are a clean example of a drug class that outgrew its original job. The mechanism is almost quaint, you pee out sugar, but the heart and kidney payoff is why they matter now .

So if you see a -gliflozin on a prescription, you can decode it: SGLT2 inhibitor, kidney mechanism, used for some mix of diabetes, heart failure, and kidney disease, with yeast infections and a rare ketoacidosis as the main things to watch .

For research and educational purposes only. Not medical advice.

pepSmart has not commissioned independent clinical review of this article.

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Sources: 3 entries, all primary canon (the FDA labels for Invokana and Farxiga plus the NIH StatPearls SGLT2 chapter). Last reviewed 2026-06-26.

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