Synjardy is a prescription medication used to lower blood sugar in people with type 2 diabetes. It combines two drugs in a single tablet: empagliflozin and metformin. The FDA has approved it for adults and children aged 10 and older as a companion to diet and exercise. It is not appropriate for type 1 diabetes and may actually increase the risk of a dangerous complication called diabetic ketoacidosis in those patients.
How Synjardy Works
Synjardy’s two ingredients attack high blood sugar from different angles. Empagliflozin works through the kidneys. Normally, your kidneys filter glucose out of the blood and then reabsorb most of it back into circulation. Empagliflozin blocks the protein responsible for that reabsorption, so excess glucose leaves your body through urine instead. The result is lower blood sugar without relying on insulin production.
Metformin, one of the most widely prescribed diabetes drugs in the world, takes a different route. It reduces the amount of sugar your liver releases into the bloodstream, slows glucose absorption from food in the intestines, and helps your cells respond more effectively to the insulin your body already makes. Together, the two components lower blood sugar more effectively than either one alone.
Beyond Blood Sugar: Heart and Kidney Benefits
Synjardy’s empagliflozin component carries additional FDA-approved indications that go well beyond glucose control. In adults with type 2 diabetes and established cardiovascular disease, it is approved to reduce the risk of death from heart-related causes. It is also approved to reduce cardiovascular death and hospitalization for heart failure in adults with heart failure, and to slow kidney disease progression in adults with chronic kidney disease at risk of getting worse.
The evidence behind these claims is substantial. In a major clinical trial, empagliflozin reduced the combined risk of cardiovascular death or heart failure hospitalization from 8.5% to 5.7% compared to placebo. Heart failure hospitalizations alone dropped from 4.1% to 2.7%. Among patients who already had kidney disease, empagliflozin cut the risk of cardiovascular death by 29% and heart failure hospitalization by 39%. For patients with peripheral artery disease, cardiovascular death dropped by 43%.
These benefits mean that Synjardy is sometimes preferred over other diabetes medications when a patient also has heart disease, heart failure, or declining kidney function. The blood sugar lowering is only part of the picture.
Available Strengths and Dosing
Synjardy comes as an immediate-release tablet taken twice daily with meals. The available strengths are 5 mg/850 mg, 5 mg/1,000 mg, 12.5 mg/850 mg, and 12.5 mg/1,000 mg (empagliflozin/metformin). Your prescriber will choose the strength based on what doses of each ingredient you need.
There is also an extended-release version called Synjardy XR, which is taken once daily. Synjardy XR is currently approved only for adults, not for pediatric patients. Taking the tablet with food helps reduce the stomach-related side effects that metformin is known for.
Common Side Effects
Because empagliflozin pushes extra sugar into your urine, it creates an environment where yeast and bacteria can thrive. Genital yeast infections are one of the more common side effects, particularly in women. Urinary tract infections also occur more frequently than with other diabetes medications. These are usually mild and treatable, but they can recur.
The metformin component commonly causes digestive issues: nausea, diarrhea, stomach pain, and gas, especially during the first few weeks. Starting at a lower dose and increasing gradually helps most people tolerate it. Because empagliflozin causes your body to excrete glucose (and water along with it), you may urinate more frequently and should stay well hydrated. Some people experience a modest drop in blood pressure, which can cause lightheadedness when standing up quickly.
Kidney Function Requirements
Synjardy requires adequate kidney function because of its metformin component. It is contraindicated in people whose estimated kidney filtration rate (eGFR) falls below 45. Your doctor will typically check kidney function before starting the medication and periodically afterward.
If you need a medical imaging procedure that uses iodinated contrast dye and your eGFR falls between 45 and 60, Synjardy should be temporarily stopped before the procedure. Kidney function is rechecked 48 hours later, and the medication is restarted once results are stable. The same temporary pause applies to patients with a history of liver disease, heavy alcohol use, or heart failure who are undergoing contrast imaging.
Lactic Acidosis Risk
Synjardy carries a boxed warning, the most serious type of FDA safety alert, for lactic acidosis. This is a rare but potentially fatal buildup of lactic acid in the blood tied to the metformin component. The risk increases when kidney function is impaired, because the body cannot clear metformin efficiently. It also rises with excessive alcohol intake, liver problems, dehydration, and during acute illness. Symptoms include unusual muscle pain, difficulty breathing, stomach discomfort, feeling unusually cold, and dizziness or lightheadedness. Lactic acidosis is a medical emergency, but the overall risk remains very low when kidney function is monitored appropriately.
Who Should Not Take Synjardy
Beyond the kidney threshold mentioned above, Synjardy is not suitable for people with type 1 diabetes or those with a history of diabetic ketoacidosis. It should not be used by anyone with severe kidney impairment or who is on dialysis. People with known hypersensitivity to either empagliflozin or metformin should avoid it as well.
If you are scheduled for surgery or any procedure requiring fasting, your prescriber may ask you to pause Synjardy temporarily. Dehydration, reduced food intake, and the stress of surgery can all increase the risk of complications from both ingredients. Restarting typically happens once you are eating and drinking normally again and kidney function is confirmed stable.