Weight loss medications can produce significant results, but it's important to go in with realistic expectations. Clinical trials show averages — individual results vary widely based on your starting weight, dose, diet, activity level, and how your body responds to the medication.
The headline numbers from clinical trials: Mounjaro produces up to 22.5% body weight loss over 72 weeks at the highest dose, and Wegovy produces up to 20.7% at its highest dose. That means someone starting at 100kg might expect to lose roughly 20–22kg over about 18 months. Older medications like Saxenda (~8%) and Orlistat (~5%) produce more modest results.
What the trials also tell us — and what gets less attention — is that most people regain weight after stopping treatment. A major Oxford study published in January 2026 found that people regain about 0.8kg per month after stopping newer GLP-1 medications, and are predicted to return to their starting weight within approximately 1.5 years. This doesn't mean the medications don't work — it reflects the reality that obesity is a chronic condition, similar to managing blood pressure or cholesterol.
The Oxford BMJ study explained — weight regain rates, metabolic markers, and what it means for long-term treatment.
ResultsClinical trial averages vs real-world results. What affects how much you lose and when.
ResultsSTEP trial data at standard and 7.2mg doses. What the numbers actually mean for you.
GuideWhat to expect at month 1, 3, 6, and 12 — aligned with the dose titration schedule.
PracticalMetabolic adaptation, dose adjustments, and practical troubleshooting when progress stalls.