Synjardy and Jardiance are not the same medication, but they share one active ingredient. Jardiance contains only empagliflozin, while Synjardy combines empagliflozin with metformin in a single tablet. Think of Synjardy as Jardiance plus metformin rolled into one pill. This distinction matters because it affects what conditions each drug can treat, who can safely take it, and what side effects to expect.
What Each Medication Contains
Jardiance is a single-ingredient medication containing empagliflozin, which belongs to a class of drugs that lower blood sugar by causing your kidneys to flush excess glucose out through urine. It works independently of insulin, which makes it useful across a range of conditions beyond diabetes.
Synjardy pairs that same empagliflozin with metformin, the most widely prescribed diabetes drug in the world. Metformin works differently: it reduces the amount of sugar your liver releases into your bloodstream and helps your body respond better to insulin. By combining two drugs that attack high blood sugar through separate pathways, Synjardy can lower blood sugar more effectively than either ingredient alone.
There’s also Synjardy XR, which uses an extended-release version of the metformin component. Standard Synjardy is typically taken twice daily with meals, while the XR version is taken once daily because the metformin dissolves more slowly.
Different Approved Uses
This is where the two medications diverge significantly. Jardiance has a broad set of FDA-approved uses. It treats type 2 diabetes, but it’s also approved on its own for heart failure and chronic kidney disease in adults, even in people who don’t have diabetes at all.
Synjardy, because it contains metformin, is limited to patients with type 2 diabetes for all of its uses. Metformin is specifically a blood sugar drug, so prescribing Synjardy to someone without diabetes wouldn’t make sense and could cause dangerously low blood sugar. That said, the empagliflozin component of Synjardy still carries cardiovascular and kidney benefits for people with type 2 diabetes. It’s approved to reduce the risk of cardiovascular death in adults with established heart disease, to reduce cardiovascular death and hospitalization for heart failure, and to slow the progression of chronic kidney disease.
In practical terms: if your doctor wants you on empagliflozin for heart failure or kidney protection and you don’t have type 2 diabetes, Jardiance is the option. If you have type 2 diabetes and are already taking metformin separately alongside Jardiance, Synjardy lets you combine both into one tablet.
Cardiovascular Benefits From the Shared Ingredient
The empagliflozin in both medications has strong evidence behind it for heart health. In a landmark trial of people with type 2 diabetes and established cardiovascular disease, empagliflozin reduced cardiovascular death by 38% and hospitalization for heart failure by 35% compared to placebo. Later trials expanded those findings beyond diabetes: in patients with heart failure and reduced heart function, empagliflozin cut the combined risk of cardiovascular death or heart failure hospitalization by 25%, driven largely by a 30% drop in heart failure hospitalizations alone. Even in patients with preserved heart function, a condition historically difficult to treat, empagliflozin reduced that same combined risk by 21%.
Both Synjardy and Jardiance deliver these benefits through their shared empagliflozin component. The metformin in Synjardy doesn’t add cardiovascular protection on this scale, so the heart and kidney benefits come from the same ingredient in both pills.
Weight Changes
Empagliflozin typically causes modest weight loss because your body is literally urinating out calories in the form of glucose. In a study of patients taking 10 mg daily for three months, the average weight loss was about 3 kg (roughly 6.5 pounds), with a corresponding drop in BMI and waist circumference of about 3 cm.
Metformin is considered weight-neutral or mildly weight-reducing, so Synjardy users can generally expect similar or slightly greater weight loss compared to Jardiance alone. Neither medication is prescribed specifically for weight loss, but this effect is a common reason patients feel better on these drugs.
Side Effects: Where They Differ Most
The side effects shared by both medications come from empagliflozin. These include urinary tract infections, genital yeast infections (more common in women), and increased urination. Because the drug works by putting sugar into your urine, it creates an environment where yeast and bacteria can thrive.
Synjardy carries an additional layer of side effects from its metformin component, and these are the main reason some people prefer taking Jardiance alone. Metformin is well known for causing gastrointestinal problems, especially when first starting. In large analyses of clinical trials, diarrhea risk was about 2.4 times higher in metformin-treated patients compared to controls, nausea risk was 1.6 times higher, and abdominal pain risk was roughly 50% higher. The overall incidence of diarrhea in metformin users runs close to 13%, with bloating around 9% and nausea around 6%.
These gut side effects often improve after a few weeks as your body adjusts. The extended-release version, Synjardy XR, tends to cause less stomach upset than the immediate-release form because the metformin dissolves more gradually.
Long-term metformin use can also reduce vitamin B12 absorption, which in rare cases leads to a type of anemia. This isn’t a concern with Jardiance alone. If you’re on Synjardy, your doctor will typically monitor your blood levels periodically.
The most serious risk unique to Synjardy is lactic acidosis, a rare but potentially life-threatening buildup of lactic acid in the blood linked to the metformin component. This is most likely to occur in people with significant kidney impairment, which is why kidney function testing is critical before and during Synjardy use.
Kidney Function Requirements
Both medications require adequate kidney function, but Synjardy has stricter limits because of metformin. Metformin is cleared through the kidneys, so impaired kidney function causes it to accumulate to dangerous levels. Jardiance should not be started in patients with an eGFR (a measure of how well the kidneys filter) below 45, and should be stopped if it stays below that threshold. It’s fully contraindicated below an eGFR of 30.
Synjardy’s metformin component adds further restrictions. Metformin is generally not recommended at lower levels of kidney function where Jardiance alone might still be cautiously continued for its heart or kidney benefits. This means some patients with declining kidney function may need to switch from Synjardy to standalone Jardiance to keep getting the empagliflozin benefits while dropping the metformin that their kidneys can no longer safely handle.
Choosing Between Them
The choice between Synjardy and Jardiance usually comes down to a simple question: do you need metformin? If you have type 2 diabetes and your doctor wants you on both empagliflozin and metformin, Synjardy consolidates two pills into one, which can simplify your routine and improve the odds you take both consistently. If you don’t have diabetes, or if you have diabetes but don’t need metformin, or if your kidneys can’t handle metformin, Jardiance is the appropriate choice.
Cost and insurance coverage also play a role. A combination pill and two separate pills may be covered differently by your plan. Some patients find it cheaper to take generic metformin alongside brand-name Jardiance than to take brand-name Synjardy, since metformin is available as a very inexpensive generic while Synjardy currently is not.