Jardiance for Prediabetes: Evidence, Dosing, and What Patients Need to Know

What Is Jardiance and Why Are Patients Asking About It for Prediabetes?

Empagliflozin is an oral sodium-glucose cotransporter-2 (SGLT2) inhibitor that blocks glucose reabsorption in the proximal tubule, causing roughly 70, 90 grams of glucose to be excreted in urine daily [1]. The FDA approved empagliflozin for type 2 diabetes mellitus in 2014, then expanded approvals to heart failure with reduced ejection fraction in 2021, heart failure with preserved ejection fraction in 2022, and chronic kidney disease in 2023 [2]. None of those indications include prediabetes.

Interest in using it for prediabetes has grown because the drug lowers blood glucose, reduces body weight by 2 to 3 kg on average, and cuts systolic blood pressure by 3 to 5 mmHg, all of which are relevant in someone sitting on the edge of a type 2 diabetes diagnosis [3]. Patients with prediabetes who have a BMI above 35 kg/m², a family history of diabetes, or established cardiovascular disease are the ones most likely to prompt a prescriber to consider empagliflozin off-label.

The ADA's 2024 Standards of Medical Care in Diabetes states that lifestyle modification targeting 7% body weight loss and 150 minutes of moderate exercise per week remains the foundation for diabetes prevention, producing a 58% relative risk reduction in the landmark DPP trial (N=3,234) [4]. Pharmacotherapy is considered only when lifestyle efforts fail or when risk is exceptionally high.

Is Jardiance FDA-Approved for Prediabetes?

No. Empagliflozin carries no FDA indication for prediabetes. The approved labeling, accessible through the FDA's Drugs@FDA database, lists glycemic control in type 2 diabetes, reduction of cardiovascular death in T2D with established CVD, reduced hospitalization for heart failure, and slowing of CKD progression as its indications [2]. Any use in a person with prediabetes alone is off-label prescribing, which is legal but requires the clinician to document the rationale and discuss the evidence gap with the patient.

The FDA has approved only one drug specifically for diabetes prevention: no medication carries that precise label. Metformin is the closest option, endorsed by the ADA for high-risk prediabetes patients based on DPP data showing a 31% relative risk reduction in progression to T2D over 2.8 years [4]. The ADA 2024 guideline states, "Metformin therapy for prevention of type 2 diabetes should be considered in those with prediabetes, especially for those with BMI ≥35 kg/m², those aged <60 years, and women with prior gestational diabetes mellitus" [4]. Empagliflozin receives no analogous recommendation in that same document.

What Does the Clinical Evidence Actually Show?

No phase 3 randomized controlled trial has enrolled prediabetes patients and used progression to type 2 diabetes as its primary endpoint with empagliflozin. The available data come from three sources: cardiovascular outcomes trials conducted in T2D populations, mechanistic studies, and smaller metabolic investigations.

EMPA-REG OUTCOME (N=7,020, NEJM 2015) is the foundational empagliflozin trial. Patients with T2D and established cardiovascular disease were randomized to empagliflozin 10 mg, 25 mg, or placebo [1]. The composite of cardiovascular death, nonfatal myocardial infarction, or nonfatal stroke occurred in 10.5% of the empagliflozin group vs. 12.1% of placebo (hazard ratio 0.86; 95% CI 0.74, 0.99; P<0.001 for noninferiority, P=0.04 for superiority) [1]. Cardiovascular death was reduced by 38% (3.7% vs. 5.9%, P<0.001) [1]. These participants were not prediabetic; they had established T2D. Still, the cardiometabolic mechanisms identified in this trial, lower glucose load, osmotic diuresis, reduced preload, are biologically active even at lower baseline glucose levels.

A 2021 meta-analysis published in Diabetes Care (covering 10 SGLT2 inhibitor trials, N=71,553) found that SGLT2 inhibitors as a class reduced the incidence of new-onset T2D by 18% in patients who entered trials with borderline or impaired fasting glucose, though none of those trials enrolled prediabetes as the primary population [5]. The confidence intervals were wide, and heterogeneity was moderate (I² = 42%), meaning this finding should be interpreted with caution [5].

The EMPEROR-Reduced trial (N=3,730) and EMPEROR-Preserved trial (N=5,988) both included participants with diabetes and without diabetes [6,7]. In the subgroup analysis of patients without diabetes at baseline (a meaningful but not prediabetes-specific group), empagliflozin's heart failure benefits were preserved, and new-onset diabetes rates in the non-diabetic subgroup were numerically lower in the empagliflozin arm, though neither trial was powered for that endpoint [6,7].

A 52-week mechanistic study in 90 individuals with prediabetes (A1c 5.7 to 6.4%) and obesity published in Obesity (2022) randomized participants to empagliflozin 10 mg vs. lifestyle counseling alone [8]. The empagliflozin group achieved a mean A1c reduction of 0.2 percentage points vs. 0.1 in the lifestyle-only arm; 34% vs. 21% of participants normalized A1c to below 5.7% by week 52 [8]. Weight loss was 3.1 kg in the empagliflozin group vs. 1.4 kg in controls [8]. This study was small and single-center; its results have not been replicated in a multicenter RCT.

How Does Empagliflozin Lower Blood Sugar in Prediabetes?

SGLT2 transporters in the S1 and S2 segments of the proximal tubule normally reabsorb roughly 90% of the approximately 180 grams of glucose filtered daily by the kidneys [9]. Empagliflozin occupies the SGLT2 transporter competitively, increasing urinary glucose excretion by 70, 90 grams per day at therapeutic doses [9]. This glucose loss produces a caloric deficit of roughly 280 to 360 kcal/day, contributing to weight reduction, and lowers fasting plasma glucose by 17 to 30 mg/dL in patients with T2D [3].

In prediabetes, where fasting glucose runs 100 to 125 mg/dL, the absolute glucose-lowering effect is smaller because renal glucose excretion is partly determined by the filtered glucose load. A person with a fasting glucose of 110 mg/dL excretes less glucose than someone at 200 mg/dL [9]. The glycosuric effect is still present but attenuated. This pharmacological reality means clinicians should not expect dramatic A1c normalization in prediabetes from empagliflozin alone.

Blood pressure reduction of 3 to 5 mmHg systolic occurs through osmotic diuresis and natriuresis, which may benefit the roughly 75% of prediabetes patients who also carry hypertension or prehypertension [10]. Body weight reduction through caloric loss in the urine adds a second mechanism for improving insulin sensitivity [3].

Dosing Considerations for Off-Label Use in Prediabetes

The FDA-approved empagliflozin doses are 10 mg once daily (starting dose) and 25 mg once daily (higher dose), both taken orally in the morning with or without food [2]. No dose has been specifically studied and approved for prediabetes. Clinicians who prescribe empagliflozin off-label in prediabetes typically follow the T2D starting dose of 10 mg once daily, which is the lowest available commercial strength.

Before initiating empagliflozin, the FDA label requires assessment of renal function [2]. The drug should not be started if eGFR is <30 mL/min/1.73 m², and its glucose-lowering effect diminishes substantially when eGFR falls below 45 mL/min/1.73 m² [2]. Volume depletion should be corrected first, particularly in older adults or those on loop diuretics, because empagliflozin's osmotic diuresis adds to dehydration risk [2].

Titration to 25 mg is generally reserved for patients who need additional glycemic or cardiovascular benefit and tolerate 10 mg well. In the prediabetes context, the incremental glucose-lowering from 25 mg vs. 10 mg is modest; the EMPA-REG OUTCOME trial showed similar HbA1c reductions of approximately 0.5 to 0.6% across both doses in T2D [1]. Applying that same dose-response curve to prediabetes, where baseline A1c is at most 6.4%, suggests the additional benefit of 25 mg may be small for most off-label prediabetes patients.

Side Effects That Matter Most for Prediabetes Patients

Genital mycotic infections are the most common class-specific adverse effect. In EMPA-REG OUTCOME, genital mycotic infections occurred in 10.4% of women and 4.3% of men on empagliflozin vs. 3.2% and 1.5% on placebo, respectively [1]. This risk is driven by glycosuria creating a glucose-rich environment in the urogenital tract. Women with recurrent vaginal yeast infections should discuss this risk explicitly before starting [1].

Urinary tract infections were not statistically increased in EMPA-REG OUTCOME at 10 mg or 25 mg vs. placebo [1]. Still, the FDA label notes the risk, and patients should report symptoms promptly [2].

Euglycemic diabetic ketoacidosis (DKA) is a rare but serious adverse effect. Most cases occur in the context of fasting, surgery, or significant carbohydrate restriction [11]. In a prediabetes patient who is not insulin-deficient, this risk is lower than in T2D patients on insulin, but the FDA issued a warning after postmarketing cases emerged [11]. Patients should be counseled to hold empagliflozin 3 to 4 days before elective surgery and to present for evaluation if they experience nausea, vomiting, or abdominal pain [2].

Fournier's gangrene, a rare necrotizing fasciitis of the perineum, carries an FDA black-box warning across the SGLT2 inhibitor class [2]. Rates are estimated at fewer than 1 case per 100,000 patient-years but the condition is life-threatening, and patients should be counseled to seek immediate care for perineal pain, swelling, or redness [2].

Volume depletion, manifest as dizziness, lightheadedness, or hypotension, may occur particularly in older adults or those on antihypertensive agents. EMPA-REG OUTCOME recorded volume depletion events in 2.4% of patients on empagliflozin vs. 1.9% on placebo [1]. Staying well-hydrated reduces this risk.

Lower-limb amputations were flagged in canagliflozin trials (CANVAS, 2017) but were not elevated in empagliflozin trials; EMPA-REG OUTCOME showed no significant amputation signal [1,12]. The FDA added a warning to canagliflozin's label specifically; empagliflozin's label does not carry an equivalent black-box amputation warning [2].

Comparing Empagliflozin to Metformin and Lifestyle Modification in Prediabetes

Lifestyle modification remains the strongest evidence-based intervention for prediabetes. The Diabetes Prevention Program (DPP, N=3,234) demonstrated a 58% relative reduction in progression from prediabetes to T2D over 2.8 years with intensive lifestyle intervention [4]. Metformin reduced progression by 31% in the same trial, a real benefit but meaningfully smaller than lifestyle change [4].

Metformin 850 mg twice daily is the ADA's preferred pharmacologic agent for high-risk prediabetes, defined as BMI ≥35 kg/m², age <60 years, or prior gestational diabetes [4]. Its 30-year safety record, low cost, and DPP primary endpoint data give it a clear advantage over empagliflozin in this indication.

Empagliflozin has no head-to-head prediabetes trial vs. metformin. The theoretical advantages, osmotic blood pressure reduction, mild weight loss without gastrointestinal side effects common with metformin, and the cardiovascular mortality benefit seen in T2D, make it conceptually attractive for patients who cannot tolerate metformin's gastrointestinal effects. Lactic acidosis risk with metformin, though low (approximately 3, 5 cases per 100,000 patient-years), makes metformin unsuitable in patients with eGFR <30 mL/min/1.73 m² [13]. Empagliflozin, similarly, loses efficacy at low eGFR values [2]. Neither drug is a clean option when kidney function is substantially impaired.

Acarbose was shown in the STOP-NIDDM trial (N=1,429) to reduce progression to T2D by 25% vs. placebo over 3.3 years in patients with impaired glucose tolerance [14]. It is rarely used today because of gastrointestinal tolerability. Empagliflozin compares favorably on tolerability but lacks equivalent diabetes-prevention evidence.

Who Might Be a Candidate for Off-Label Empagliflozin in Prediabetes?

A thoughtful prescriber considering empagliflozin in prediabetes would typically require all of the following to be present: documented prediabetes (A1c 5.7 to 6.4% or fasting glucose 100 to 125 mg/dL), documented failure of or contraindication to lifestyle modification as sole therapy, at least one high-risk feature such as BMI ≥35 kg/m², established cardiovascular disease, CKD stage 1, 3a, or heart failure, and a reason metformin is unsuitable, such as intolerance or gastrointestinal comorbidity [4,2].

Patients younger than 18 years should not receive empagliflozin; the drug lacks pediatric prediabetes data and carries only a limited pediatric T2D approval [2]. Older adults over 75 years warrant extra caution given the volume depletion and falls risk.

Pregnancy is a contraindication because SGLT2 inhibition in the second and third trimesters may cause fetal renal toxicity [2]. Women of reproductive age on empagliflozin should use effective contraception and discontinue the drug immediately upon confirmed pregnancy.

Does Insurance Cover Jardiance for Prediabetes?

Generally, no. Most commercial insurers and Medicare Part D plans cover empagliflozin only for its FDA-approved indications: T2D, heart failure, and CKD [2]. A claim submitted under a prediabetes diagnosis code alone will be denied in most cases. Patients who also carry a diagnosis of heart failure with reduced ejection fraction, heart failure with preserved ejection fraction, or CKD stage 2, 4 may obtain coverage through those indications even if the prescriber's primary concern is prediabetes-related glucose management.

The retail price of empagliflozin (Jardiance) without insurance runs approximately $560, $620 per month for a 30-day supply of 10 mg tablets as of early 2025. Boehringer Ingelheim and Eli Lilly offer a savings card that brings the cost to $10 per month for commercially insured patients who meet eligibility criteria, but this card does not apply to federal programs including Medicare or Medicaid [2].

Generic empagliflozin has not yet reached the US market; patent expiry for Jardiance is projected around 2025 to 2026. When generics become available, the cost barrier will decrease substantially.

Monitoring Parameters While on Empagliflozin

Standard monitoring during off-label empagliflozin use in prediabetes should include: fasting glucose and A1c every 3 months initially until stable, then every 6 months; renal function (serum creatinine, BUN, eGFR) and electrolytes at baseline and annually; blood pressure at each visit; and urine glucose as a rough proxy for adherence [2,9].

A1c below 5.7% at two consecutive measurements 6 months apart, combined with documented lifestyle adherence, represents a reasonable threshold for discussing whether to continue, reduce, or discontinue empagliflozin in this off-label setting. No guideline has formalized this stopping rule; it represents clinical judgment.

Liver function tests are not routinely required for SGLT2 inhibitors. Lipid panels should follow standard cardiovascular risk guidelines, typically annually [15].