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GLP-1 Weight Loss Calculator
Estimate your projected weight loss on Ozempic, Wegovy, Mounjaro, or Zepbound based on clinical trial data. Enter your details below.
How This Calculator Works
This calculator uses data from major clinical trials to project your weight loss on GLP-1 receptor agonist medications. Here’s what powers the estimates:
- Wegovy (semaglutide 2.4mg): Based on the STEP 1 trial — average 16.9% body weight loss over 68 weeks
- Ozempic (semaglutide 1mg): Based on SUSTAIN trials — average ~10.5% loss (lower dose, off-label for weight loss)
- Mounjaro/Zepbound (tirzepatide 15mg): Based on SURMOUNT-1 trial — average 22.5% loss over 72 weeks
These are averages — some people lose more, some less. Your results depend on diet, exercise, adherence, genetics, starting BMI, and other factors. The dosing timeline shows the standard titration schedule prescribed by most providers.
Frequently Asked Questions
How much weight can I expect to lose on Ozempic?
Ozempic (semaglutide 1mg) was designed for type 2 diabetes, not weight loss specifically. In clinical trials, patients lost an average of 5-10% of body weight. For dedicated weight loss, Wegovy (semaglutide 2.4mg) typically achieves 15-17% loss over 68 weeks.
Is Mounjaro better than Ozempic for weight loss?
Head-to-head trials (SURMOUNT-5) show tirzepatide (Mounjaro/Zepbound) produces greater weight loss than semaglutide — approximately 22.5% vs 16.9% body weight loss. However, tirzepatide is a dual GIP/GLP-1 agonist, while semaglutide is GLP-1 only. Both are effective; the best choice depends on your individual health profile, insurance coverage, and provider recommendations.
When will I start seeing results?
Most people notice weight loss within the first 4-8 weeks, even at the lowest starting dose. Significant results (5%+ body weight) typically appear around weeks 12-16. Maximum weight loss is usually reached between weeks 52-72, depending on the medication.
How much do GLP-1 medications cost?
Without insurance, GLP-1 medications cost approximately $1,000-$1,100 per month. With commercial insurance that covers the medication, costs can drop to $25-$150/month. Manufacturer savings cards are available for many patients. As of 2025, compounded semaglutide options are severely limited due to FDA enforcement after the shortage ended.
Will I gain the weight back if I stop?
Studies show that approximately two-thirds of weight lost on GLP-1 medications is regained within a year of stopping. This is why combining medication with sustainable lifestyle changes — proper nutrition, resistance training for muscle preservation, and behavioral modifications — is critical for long-term success.
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