Farxiga (dapagliflozin) most commonly causes genital yeast infections, urinary tract infections, and increased urination. These side effects stem directly from how the drug works: it lowers blood sugar by forcing your kidneys to flush excess glucose out through your urine. That extra sugar in the urinary tract creates a breeding ground for bacteria and yeast. Most side effects are mild and manageable, but a few rare ones require immediate attention.
How Farxiga Causes Side Effects
Farxiga belongs to a class of drugs called SGLT2 inhibitors. Normally, your kidneys reabsorb glucose back into your bloodstream. Farxiga blocks that process, so sugar passes into your urine instead. This is the intended effect for managing type 2 diabetes, heart failure, or chronic kidney disease, but it also means your urinary tract is regularly exposed to glucose-rich urine. That environment encourages yeast and bacteria to grow, which explains the two most common categories of side effects.
The drug also has a mild diuretic effect. By pulling more glucose into urine, it pulls water along with it. This leads to more frequent urination and, for some people, dehydration or drops in blood pressure.
Genital Yeast Infections
Genital yeast infections are the side effect most clearly linked to Farxiga compared to a placebo. In the large DAPA-CKD clinical trial, 1% of patients on Farxiga developed a genital infection versus just 0.1% of those on placebo, a tenfold difference. Women are more commonly affected, but men can develop yeast infections on the foreskin or tip of the penis as well.
Symptoms include itching, redness, irritation, and sometimes a white discharge. These infections are typically mild and respond well to standard antifungal treatments. Wearing cotton underwear and breathable clothing, and keeping the genital area clean and dry, can help reduce your risk. Some patients in clinical trials did need to pause or stop taking Farxiga because of recurring infections, though this was uncommon.
Urinary Tract Infections
UTIs occurred in about 5.2% of Farxiga patients compared to 4.9% on placebo in clinical trials. That difference is small, and researchers continue to debate how much of the UTI risk comes from the drug itself versus the underlying conditions it treats (diabetes and kidney disease both independently raise UTI risk). Still, the mechanism makes biological sense: glucose in the urine provides fuel for bacterial growth.
Watch for the typical UTI signs: burning during urination, a frequent or urgent need to go, cloudy or strong-smelling urine, or pelvic discomfort. Staying well hydrated helps flush bacteria from the urinary tract. About 1.3% of Farxiga patients in trials had a UTI serious enough to require hospitalization, compared to 0.8% on placebo.
Dehydration and Low Blood Pressure
Because Farxiga increases urine output, it can leave you mildly dehydrated. Some people experience dizziness, lightheadedness, or feeling faint when standing up, all signs of a drop in blood pressure. In clinical trials, volume depletion events (including dehydration and low blood pressure) occurred in about 1.5% to 1.7% of patients aged 65 and older on the 10 mg dose, compared to 0.4% to 0.8% on placebo.
You’re at higher risk for this side effect if you’re over 65, have reduced kidney function, or take a diuretic (water pill). Drinking enough fluids throughout the day is the simplest way to offset this. If you feel persistently dizzy or lightheaded, especially when getting up from sitting or lying down, that’s worth bringing up with your prescriber.
Kidney Function Changes
When you first start Farxiga, your kidney filtration rate typically dips slightly. This shows up in blood tests as a small rise in creatinine, a waste product the kidneys filter. These changes generally appear within the first two weeks of treatment and then stabilize. They’re considered a predictable, transient response to the drug rather than a sign of kidney damage. In fact, Farxiga is approved specifically to protect kidney function over the long term in people with chronic kidney disease.
Ketoacidosis With Normal Blood Sugar
One of the more serious risks is a condition called euglycemic ketoacidosis. Normally, diabetic ketoacidosis happens when blood sugar spikes dangerously high. But Farxiga can trigger a version where your blood builds up harmful acids (ketones) even though your blood sugar reads below 200 mg/dL. This is dangerous partly because the normal-looking glucose level can delay diagnosis.
Certain situations raise the risk: skipping meals or following a very low-carb diet, heavy alcohol use, dehydration, surgery, serious illness or infection, and reducing your insulin dose. People with a low or normal body mass index appear particularly vulnerable. Symptoms include nausea, vomiting, abdominal pain, fatigue, and difficulty breathing. If you notice these symptoms, especially in combination, seek medical attention promptly, even if your blood sugar monitor shows a normal number.
Fournier’s Gangrene
This is extremely rare but important to know about. Fournier’s gangrene is a rapidly spreading, life-threatening infection of the skin and tissue in the genital or perineal area (between the genitals and anus). The UK’s drug safety agency identified just 6 cases across an estimated 548,565 patient-years of SGLT2 inhibitor use. Both men and women can be affected.
It sometimes starts as what looks like a genital infection or abscess. The warning signs that distinguish it from an ordinary infection are severe pain, swelling, or redness in the genital area accompanied by fever or a general feeling of being unwell. This requires emergency medical care.
Who Faces Higher Risk
Age is the clearest risk modifier. In clinical trials, patients 65 and older experienced more blood pressure drops and dehydration-related events than younger adults. About 24% of Farxiga-treated patients in the main diabetes trials were over 65, giving researchers a solid dataset to identify this pattern. Reduced kidney function and concurrent use of diuretics compound the risk further.
Pregnant women face unique dangers. Pregnancy naturally shifts the body toward increased fat breakdown and ketone production, making ketoacidosis more likely with an SGLT2 inhibitor on board. Farxiga is not recommended during pregnancy.
People with type 1 diabetes are also at elevated risk for ketoacidosis if they use Farxiga, and the drug is not approved for that population. The risk applies even at normal blood sugar levels, making it especially tricky to catch early.