Short answer: In the label's pooled 26-week trials, the most common Steglatro side effect was genital yeast infection: 9.1% on 5 mg and 12.2% on 15 mg vs 3.0% on placebo in women, and 3.7% and 4.2% vs 0.4% in men. Urinary tract infections, headache, vaginal itching, more urination and thirst were also more common than on placebo. Steglatro has no boxed warning.
What Steglatro is approved for: Steglatro is an SGLT2 inhibitor approved, along with diet and exercise, to improve blood sugar control in adults with type 2 diabetes. It is not recommended for blood sugar control in type 1 diabetes (section 1).
Source
STEGLATRO (ertugliflozin) tablets, for oral use, prescribing information and Medication Guide. Merck Sharp & Dohme. DailyMed, version published June 23, 2026. DailyMed setid e6f3e718-bb99-48f1-ab94-b9f0af05fed6
No. The current Steglatro label has no boxed warning.
These are the label's own numbers from the Adverse Reactions section. Where the label compares with placebo (a dummy treatment), both columns are shown, so you can see how much more often a reaction happened on Steglatro.
| Adverse reaction | Placebo (N=515) | STEGLATRO 5 mg (N=519) | STEGLATRO 15 mg (N=510) |
|---|---|---|---|
| Female genital mycotic infections | 3.0% | 9.1% | 12.2% |
| Male genital mycotic infections | 0.4% | 3.7% | 4.2% |
| Urinary tract infections | 3.9% | 4.0% | 4.1% |
| Headache | 2.3% | 3.5% | 2.9% |
| Vaginal pruritus | 0.4% | 2.8% | 2.4% |
| Increased urination | 1.0% | 2.7% | 2.4% |
| Nasopharyngitis | 2.3% | 2.5% | 2.0% |
| Back pain | 2.3% | 1.7% | 2.5% |
| Weight decreased | 1.0% | 1.2% | 2.4% |
| Thirst | 0.6% | 2.7% | 1.4% |
Three 26-week trials: one alone and two added to metformin or metformin plus sitagliptin. Female and male genital infection and vaginal itching rates use only women or only men as the denominator.
| Study and event | Placebo | STEGLATRO 5 mg | STEGLATRO 15 mg |
|---|---|---|---|
| Monotherapy (26 weeks), overall | 1 (0.7) | 4 (2.6) | 4 (2.6) |
| Monotherapy (26 weeks), severe | 0 (0.0) | 0 (0.0) | 2 (1.3) |
| Add-on to metformin (26 weeks), overall | 9 (4.3) | 15 (7.2) | 16 (7.8) |
| Add-on to insulin with or without metformin (18 weeks), overall | 130 (37.5) | 137 (39.4) | 144 (38.9) |
| Add-on to insulin with or without metformin (18 weeks), severe | 12 (3.5) | 13 (3.7) | 19 (5.1) |
| Add-on to metformin and a sulfonylurea (18 weeks), overall | 17 (14.5) | 20 (20.0) | 30 (26.5) |
Overall means glucose 70 mg/dL or lower; severe means needing help, losing consciousness or having a seizure. Values are N (%). The full table also covers add-on to metformin plus sitagliptin, to a sulfonylurea alone, and insulin users with moderate kidney impairment.
Lower limb amputation in the long-term heart outcomes study: 4.7, 5.7 and 6.0 events per 1,000 patient-years on placebo, 5 mg and 15 mg. Across seven trials: 0.1% on comparator, 0.2% on 5 mg and 0.5% on 15 mg.
Fluid-loss reactions (dehydration, dizziness on standing, fainting, low blood pressure) in people with moderate kidney impairment: 0% on placebo, 4.4% on 5 mg and 1.9% on 15 mg.
Urinary tract infections in VERTIS CV: 10.2% on placebo, 12.2% on 5 mg and 12.0% on 15 mg; serious ones 0.8%, 0.9% and 0.4%.
Phimosis (tight foreskin) was reported in 8 of 1729 (0.5%) men on ertugliflozin; four needed circumcision. Stopping for genital yeast infection: 0.6% of women and 0.2% of men on Steglatro vs 0% on placebo.
LDL cholesterol rose 2.6% on 5 mg and 5.4% on 15 mg relative to placebo at week 26. Creatinine rises and eGFR falls within weeks of starting, then stabilizes.
The Warnings and Precautions part of the label lists these. Each line gives the label's heading and what it means in plain words.
Who should not use it. Steglatro is not used by people allergic to ertugliflozin or its ingredients; angioedema has occurred.
Ketoacidosis. Steglatro greatly raises the risk of diabetic ketoacidosis in type 1 diabetes, and fatal ketoacidosis has been reported in type 2 diabetes with SGLT2 inhibitors. It can happen with blood sugar below 250 mg/dL. Triggers include lower insulin doses, fever, eating little, a ketogenic diet, surgery, fluid loss and alcohol abuse. If suspected, Steglatro is stopped.
Lower limb amputation. Amputations, mostly of toes and feet, were more frequent on Steglatro in the long-term heart outcomes study. The label stresses routine foot care and watching for leg or foot sores, ulcers and infections.
Fluid loss and kidney injury. Steglatro can lower fluid volume and cause low blood pressure or kidney changes; acute kidney injury, some needing dialysis, has been reported. Risk is higher with eGFR under 60, older age, low blood pressure or loop diuretics.
Genital and urinary infections, including Fournier's gangrene. Steglatro raises the risk of urinary and genital yeast infections. Serious infections including urosepsis, kidney infection and Fournier's gangrene, a rare life-threatening infection of the genital area, have occurred with SGLT2 inhibitors.
Low blood sugar with insulin or sulfonylureas. Steglatro may raise the risk of low blood sugar with insulin or a sulfonylurea; a lower dose of those may reduce the risk.
From the Medication Guide that comes with Steglatro:
Dose Track has a side-effect log. Each entry records the symptom, a severity (none, mild, moderate, severe or life-threatening), the date and an optional note, and can be tied to a specific dose or logged on its own. The history screen shows what you logged over time, which makes it easier to tell your prescriber when a reaction started and whether it is easing. The app records what you enter; it does not judge whether a symptom is serious. For anything on the label's call-your-doctor list, call your doctor.
This page is what the FDA label says, in plain words. It is not medical advice. Follow your prescriber, and ask them or your pharmacist about anything here.