Weight Loss Results
Mounjaro Before and After Results
Quick Answer: Clinical trial data from SURMOUNT-1 shows that patients on Mounjaro 15 mg lose an average of 22.5% of body weight over 72 weeks — more than any other currently licensed weight management treatment. In practical terms, a patient starting at 100 kg could expect to lose approximately 8–11 kg within three months, 13–16 kg by six months and up to 22 kg within 72 weeks.22.5%avg weight loss at 15 mg (SURMOUNT-1, 72 wks)
~7–9%typical weight loss at 3 months
57%of patients lost ≥20% of body weight
SURMOUNT-1 Trial Data
Clinical Trial Results
The landmark SURMOUNT-1 trial enrolled 2,539 adults with obesity (BMI ≥30 or ≥27 with a weight-related comorbidity) without type 2 diabetes. Participants received tirzepatide at 5 mg, 10 mg or 15 mg, or placebo, alongside lifestyle intervention for 72 weeks.
Results by Starting Weight
| Outcome Measure | Tirzepatide 5 mg | Tirzepatide 10 mg | Tirzepatide 15 mg | Placebo |
|---|---|---|---|---|
| Mean weight loss | 15.0% | 19.5% | 22.5% | 3.1% |
| ≥5% weight loss | 85% | 89% | 91% | 35% |
| ≥10% weight loss | 69% | 79% | 83% | 16% |
| ≥15% weight loss | 48% | 67% | 73% | 7% |
| ≥20% weight loss | 28% | 50% | 57% | 2% |
| Mean absolute weight loss | ~15.4 kg | ~19.8 kg | ~21.8 kg | ~3.2 kg |
| Starting Weight | 3 Months (~8%) | 6 Months (~15%) | 12 Months (~20%) |
|---|---|---|---|
| 80 kg | ~6 kg → 74 kg | ~12 kg → 68 kg | ~16 kg → 64 kg |
| 100 kg | ~8 kg → 92 kg | ~15 kg → 85 kg | ~20 kg → 80 kg |
| 120 kg | ~10 kg → 110 kg | ~18 kg → 102 kg | ~24 kg → 96 kg |
| 140 kg | ~11 kg → 129 kg | ~21 kg → 119 kg | ~28 kg → 112 kg |
SURMOUNT-5 Head-to-Head
Mounjaro vs Wegovy — Head to Head
The SURMOUNT-5 trial — the first direct comparison of tirzepatide and semaglutide 2.4 mg in adults with obesity — confirmed Mounjaro's superiority. Patients on tirzepatide achieved approximately 20.2% weight loss versus 13.7% on semaglutide over 72 weeks — approximately 47% more weight loss with Mounjaro.
Mounjaro (Tirzepatide)~20.2% average weight loss at 72 weeks in SURMOUNT-5. Larger waist circumference reduction and greater cardiometabolic improvements.
Wegovy (Semaglutide)~13.7% average weight loss at 72 weeks in SURMOUNT-5. Well-established track record with additional cardiovascular risk reduction indication.
FAQs
Frequently Asked Questions
SURMOUNT-1 data shows average weight loss of approximately 22.5% of body weight over 72 weeks at the 15 mg maintenance dose — approximately 22 kg for someone starting at 100 kg. More than half of patients lost 20% or more.
At three months, most patients have reached the 7.5 mg dose and typically lost between 7% and 9% of starting body weight. For someone starting at 100 kg this means approximately 7–9 kg — notably higher than the typical 5–7% seen with Wegovy at the same timepoint.
Yes — SURMOUNT-5, the first head-to-head trial, showed tirzepatide produces approximately 47% more weight loss than semaglutide 2.4 mg (20.2% vs 13.7% over 72 weeks). For patients whose primary goal is maximum weight loss, Mounjaro is the stronger clinical choice.
Appetite reduction begins within the first one to two weeks even at the 2.5 mg starting dose. Significant weight loss builds across the escalation schedule, with the most rapid weekly reductions typically occurring between months three and six as the dose approaches 10–15 mg.
The SURMOUNT-4 trial showed patients who discontinued tirzepatide after 36 weeks regained approximately two-thirds of their lost weight within 88 weeks of stopping — consistent with Wegovy withdrawal data. This underscores Mounjaro as a long-term treatment for a chronic condition.
Exercise — particularly resistance training — significantly improves body composition outcomes and helps preserve lean muscle mass. It has a modest additional impact on total weight lost but a meaningful impact on the quality of weight loss and longer-term metabolic health.
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Jastreboff AM et al. SURMOUNT-1. N Engl J Med. 2022. SURMOUNT-5 results 2025. NICE TA1026. 2024. Happy Pharmacy (GPhC No. 9012585). Educational purposes only.