Medically reviewed by a licensed healthcare professional. Last updated March 2026.
SURMOUNT-1 Results at Each Dose
The SURMOUNT-1 trial is the landmark study for Zepbound. It enrolled 2,539 adults with BMI 30+ (or BMI 27+ with a comorbidity), without diabetes, and ran for 72 weeks:
- SURMOUNT-1 trial: 20.9% average weight loss at 15 mg over 72 weeks. That is about 48 pounds for a 230-pound person.
- Over half of patients on the highest dose lost 20% or more of their body weight, previously a threshold reserved for bariatric surgery.
- Tirzepatide consistently outperforms semaglutide in weight loss. SURMOUNT-1 results exceed STEP 1 by approximately 6 percentage points.
- Visual changes often become noticeable earlier with Zepbound than semaglutide, typically by weeks 4 to 6.
| Dose | Average Weight Loss | Average Lbs Lost (230 lb start) | Lost 10%+ | Lost 15%+ | Lost 20%+ |
|---|---|---|---|---|---|
| 5 mg | 15.0% | 34.5 lbs | 69.5% | 50.2% | 33.9% |
| 10 mg | 19.5% | 44.9 lbs | 78.9% | 65.0% | 49.1% |
| 15 mg | 20.9% | 48.1 lbs | 83.5% | 70.6% | 56.7% |
| Placebo | 3.1% | 7.1 lbs | 13.5% | 6.0% | 1.3% |
These numbers are worth pausing on. At the 15 mg dose, the average participant lost nearly 50 pounds. More than half crossed the 20% threshold, which transforms not just appearance but metabolic health, joint function, sleep quality, and cardiovascular risk.
Month-by-Month: What to Realistically Expect
Month 1 (2.5 mg)
Typical weight loss: 3 to 6 pounds
The starting dose is about adjusting to the medication. But even at 2.5 mg, tirzepatide's dual mechanism begins working. Patients commonly report a dramatic reduction in food noise and cravings. The GIP receptor activation may contribute to earlier appetite effects compared to GLP-1-only medications.
Visual changes: minimal. Internal changes: significant. Your relationship with food begins shifting.
Month 2 (5 mg)
Typical cumulative weight loss: 8 to 14 pounds
At 5 mg, you are on a dose that produced 15% average weight loss in clinical trials (over 72 weeks). Weight loss is accelerating. Your face may look thinner. You are probably noticing your belt needs tightening or your pants are looser.
Month 3 (7.5 mg)
Typical cumulative weight loss: 14 to 22 pounds
This is when the visual transformation becomes apparent to people around you. A loss of 14+ pounds is typically visible in the face, neck, and midsection. Many patients drop their first full clothing size during month 3.
Month 4 (10 mg)
Typical cumulative weight loss: 20 to 30 pounds
The 10 mg dose is where many patients find their optimal balance of results and tolerability. Weight loss is consistent at 1.5 to 2+ pounds per week for many. Lab values for cholesterol, blood pressure, and blood sugar often show meaningful improvement.
Month 6 (10 to 15 mg)
Typical cumulative weight loss: 30 to 42 pounds
By the half-year mark, the transformation is dramatic. For someone who started at 230 pounds, being down 30+ pounds is life-changing. Multiple clothing sizes, visible muscle definition (if exercising), comments from everyone you know.
Month 9 (Maintenance dose)
Typical cumulative weight loss: 38 to 48 pounds
Weight loss begins to slow as your body approaches its new equilibrium. This is normal and expected. The rate of loss typically drops to 0.5 to 1 pound per week.
Month 12 (Maintenance dose)
Typical cumulative weight loss: 42 to 52 pounds
Most patients have reached or are near their plateau. The SURMOUNT-4 trial showed that patients who continued tirzepatide after the initial weight loss period maintained their results and even lost slightly more weight, while those switched to placebo regained most of what they had lost.
Zepbound vs. Semaglutide: Head-to-Head Comparison
While there is no single trial directly comparing Zepbound to Wegovy, we can compare across trials:
| Metric | Zepbound 15 mg (SURMOUNT-1) | Wegovy 2.4 mg (STEP 1) |
|---|---|---|
| Average weight loss | 20.9% | 14.9% |
| Lost 10%+ | 83.5% | 69.1% |
| Lost 15%+ | 70.6% | 50.5% |
| Lost 20%+ | 56.7% | 32.0% |
| Trial duration | 72 weeks | 68 weeks |
Across every metric, tirzepatide outperforms semaglutide. The gap is particularly wide at the highest thresholds: 56.7% vs. 32.0% achieving 20%+ weight loss. However, these are cross-trial comparisons with different patient populations, so some caution is warranted.
The SURMOUNT-5 trial, which directly compared tirzepatide to semaglutide, confirmed tirzepatide's superiority. At 72 weeks, tirzepatide patients lost 20.2% of body weight versus 13.7% for semaglutide.
Beyond the Scale: Non-Weight Changes
Some of the most meaningful Zepbound transformations are not about pounds:
- Waist circumference: SURMOUNT-1 patients on 15 mg lost an average of 19.4 cm (7.6 inches) from their waist.
- Blood pressure: Systolic blood pressure decreased by 7.4 mmHg on average at the 15 mg dose.
- Triglycerides: Reduced by 25.6% at the 15 mg dose.
- Sleep apnea: The SURMOUNT-OSA trial showed tirzepatide reduced apnea-hypopnea index by approximately 55% at the 10/15 mg dose, with some patients no longer meeting the criteria for obstructive sleep apnea.
- Physical function: Patients reported significant improvements in mobility, exercise capacity, and joint pain.
Compounded GLP-1 medications are not FDA-approved. While legal during FDA-recognized drug shortages, they do not undergo the same rigorous testing as brand-name drugs. Always verify your provider uses a licensed 503A or 503B compounding pharmacy.
Managing Expectations
Even with Zepbound's impressive data, not everyone will match the trial averages. Some practical considerations:
- Your starting weight matters. Someone starting at 300 pounds may lose 60 pounds (20%), while someone starting at 180 may lose 27 pounds (15%). Both are successful outcomes.
- Rate of loss is not constant. Rapid early loss followed by a plateau is the typical pattern, not a sign of failure.
- Body composition matters more than scale weight. If you are exercising, you may be building muscle while losing fat, which can slow scale changes while dramatically improving how you look and feel.
- Comparing yourself to social media is counterproductive. The most extreme transformations get the most shares, creating a skewed picture of typical results.
Cost and How to Get Started
Brand-name Zepbound runs over $1,000 per month at list price, but self-pay through LillyDirect starts at $299 per month. With commercial insurance and the Eli Lilly savings card, copays can be as low as $25 per month. Compounded tirzepatide (the same active ingredient) is available through some telehealth providers starting around $133 per month, though it is not FDA-approved.
If cost is a barrier, semaglutide-based alternatives like Wegovy or Ozempic may be more affordable, especially in compounded form. Mounjaro uses the same tirzepatide compound but is FDA-approved for diabetes rather than weight loss. See our cheapest providers guide for the most affordable options.
Ready to start your weight loss journey? Find a GLP-1 clinic near you and connect with a qualified provider today.
Medical Disclaimer: This content is for informational purposes only and does not constitute medical advice, diagnosis, or treatment. Individual results vary. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you are experiencing a medical emergency, call 911.