SGLT2 Inhibitors for Type 2 Diabetes: What You Need to Know About Benefits and Risks

For people with type 2 diabetes, managing blood sugar isn't just about counting carbs or taking insulin anymore. A new class of medications called SGLT2 inhibitors has changed the game-not just for blood sugar, but for the heart and kidneys too. These drugs, including Jardiance, Farxiga, Invokana, and Steglatro, were originally designed to lower glucose. But what they’ve turned out to do goes far beyond that. They reduce hospital stays for heart failure, slow kidney damage, and even lower the risk of dying from heart-related causes. And yet, they come with real risks: infections, dehydration, and rare but dangerous conditions like diabetic ketoacidosis. If you’re considering or already taking one of these drugs, you need to know both sides.

How SGLT2 Inhibitors Actually Work

Unlike most diabetes meds that push insulin or block sugar production, SGLT2 inhibitors work in the kidneys. They block a protein called SGLT2, which normally reabsorbs glucose back into the blood from urine. When this protein is turned off, excess sugar gets flushed out through the pee-about 40 to 100 grams a day. That’s like dumping two to five sugar packets into the toilet every day. The result? Blood sugar drops by 0.5% to 1% on HbA1c, without causing dangerous low blood sugar episodes. This makes them safer than sulfonylureas or insulin for many patients.

Because they’re excreting sugar, these drugs also cause a small amount of weight loss-usually 2 to 3 kilograms over a few months. Blood pressure drops too, by about 3 to 5 mmHg, just from the extra fluid loss. That’s why they’re now recommended not just for diabetes, but for heart and kidney protection, even in people without diabetes.

The Big Benefits: Heart and Kidneys First

The biggest shift in how doctors use SGLT2 inhibitors happened after large clinical trials proved they save lives. The EMPA-REG OUTCOME trial showed empagliflozin reduced cardiovascular death by 38% in patients with existing heart disease. The CREDENCE trial found canagliflozin cut the risk of kidney failure, dialysis, or death from kidney disease by 30%. These weren’t small effects-they were game-changers.

Now, the American Diabetes Association says if you have type 2 diabetes and heart failure, chronic kidney disease, or a history of heart attack, you should start an SGLT2 inhibitor right away-even before metformin in some cases. That’s a massive change from just a decade ago, when these drugs were last-resort options after other treatments failed.

Even more surprising: these drugs help people with heart failure even if they don’t have diabetes. The DAPA-HF and EMPEROR-Preserved trials showed dapagliflozin and empagliflozin cut hospitalizations for heart failure by about 30%, regardless of whether the patient had type 2 diabetes. That’s why cardiologists now prescribe them for heart failure patients across the board.

Common Side Effects: Infections and Dehydration

With benefits come trade-offs. The most common side effects are genital yeast infections and urinary tract infections. About 6 to 11% of women taking these drugs get yeast infections, compared to just 1 to 2% on placebo. Men get them too-less often, but still noticeably more than usual. These aren’t life-threatening, but they’re annoying enough that many people stop taking the drug. Recurrent infections were the top reason one patient on Drugs.com quit Farxiga after six months, even though her blood sugar was under control.

Another issue is volume depletion. Because you’re peeing out more sugar and fluid, you can get dehydrated-especially if you’re older, on diuretics, or skip meals. This can lead to dizziness, low blood pressure, or even acute kidney injury. The FDA requires a black box warning for this risk. Doctors now tell patients to drink more water, avoid excessive alcohol, and hold the medication during illness or surgery.

The Rare but Serious Risk: Euglycemic Diabetic Ketoacidosis

One of the most dangerous, yet underrecognized, risks is euglycemic diabetic ketoacidosis (euDKA). Unlike classic DKA, where blood sugar is sky-high, euDKA happens when blood sugar is only mildly elevated-sometimes even normal. That makes it easy to miss. The body starts breaking down fat for energy, producing toxic ketones. Symptoms include nausea, vomiting, abdominal pain, and confusion.

Studies show euDKA occurs in about 0.1% to 0.3% of SGLT2 inhibitor users, compared to less than 0.1% in those not taking them. Most cases happen during illness, fasting, or after surgery. A 2022 study found 42% of euDKA cases occurred in patients with kidney function above normal. That means even healthy-looking patients aren’t immune. If you’re on one of these drugs and feel unwell, check for ketones with a urine strip or blood test-even if your glucose looks fine.

Who Should Avoid These Drugs

SGLT2 inhibitors aren’t for everyone. They’re not approved for type 1 diabetes-using them there increases ketoacidosis risk dramatically. They’re also not recommended if your kidney function is too low. Most require dose adjustments if your eGFR drops below 60, and should be stopped if it falls below 45. Starting them when eGFR is under 30 is contraindicated.

People with a history of recurrent genital infections or urinary tract infections may want to avoid them unless the benefits clearly outweigh the discomfort. Those with low blood pressure or on strong diuretics should be monitored closely. And while they’re great for weight loss, they’re not a magic solution-patients who combine them with poor diet or inactivity often see diminishing returns.

Cost and Access: A Real Barrier

These drugs are expensive. A 30-day supply costs around $600 out of pocket in the U.S. That’s a major reason why 33% of patients stop taking them within a year. But most insurance plans cover them, and manufacturer assistance programs can bring the monthly cost down to $10-$25. Still, many patients-especially those on high-deductible plans or without insurance-can’t afford them. That’s a problem, because the long-term savings from avoiding heart attacks, kidney failure, and hospital stays far outweigh the drug cost.

Generic versions won’t be available until 2027-2029. Until then, patients need to work with their providers to get prior authorizations or apply for patient support programs. Some clinics now use SGLT2 inhibitors as part of population health programs, prioritizing them for high-risk patients to reduce overall healthcare spending.

How to Use Them Safely

If you’re prescribed an SGLT2 inhibitor, here’s what you need to do:

1. Get your kidney function tested (eGFR) before starting and every 3-6 months after.
2. Stay hydrated-drink water regularly, especially during hot weather or exercise.
3. Watch for signs of infection: itching, burning, redness, or unusual discharge. Treat yeast infections early.
4. Know the symptoms of ketoacidosis: nausea, vomiting, stomach pain, confusion, rapid breathing. Test for ketones if you’re sick.
5. Hold the medication during acute illness, surgery, or if you can’t eat for more than a day.
6. Don’t stop taking it without talking to your doctor-even if you feel fine.

Many patients report life-changing results. One man with heart failure saw his ejection fraction rise from 28% to 42% in 18 months on Jardiance. Another lost 15 pounds and dropped his A1c from 8.2 to 6.8 without changing his diet. But these outcomes aren’t guaranteed. Success depends on using the drug correctly, monitoring for side effects, and staying in touch with your care team.

The Future of SGLT2 Inhibitors

The FDA approved dapagliflozin in October 2023 for chronic kidney disease-even in people without diabetes. That’s a huge milestone. The EMPA-KIDNEY trial showed empagliflozin slowed kidney decline in patients with advanced kidney disease, regardless of diabetes status. Research is now exploring whether these drugs can prevent heart failure in people at high risk but without symptoms yet.

They’re not perfect. They’re expensive. They have side effects. But for the right patient, they’re one of the most powerful tools we have to prevent disability and death from diabetes complications. The question isn’t whether they work-it’s whether you’re getting the right one, at the right time, with the right support.

Next Steps: What to Do If You’re Considering SGLT2 Inhibitors

If you have type 2 diabetes and heart or kidney concerns, talk to your doctor about whether an SGLT2 inhibitor could help. Bring up your history of infections, kidney function, and any recent hospitalizations. Ask for a baseline eGFR test and discuss the pros and cons specific to your situation. Don’t assume they’re right for you-or wrong for you-just because someone else had a good or bad experience.

If you’re already on one, keep your follow-up appointments. Track your weight, fluid intake, and any symptoms of infection or illness. If you feel off, don’t wait-check for ketones and call your provider. These drugs can be life-saving, but only if you use them wisely.