GLP-1 Weight Loss Calculator (Wegovy, Mounjaro, Zepbound, Ozempic)
Glucagon-like peptide-1 (GLP-1) receptor agonists and dual GLP-1/GIP receptor agonists represent a landmark advancement in obesity medicine. Medications like Semaglutide (Wegovy, Ozempic) and Tirzepatide (Zepbound, Mounjaro) enhance glucose-dependent insulin secretion, slow gastric emptying, and suppress appetite centers in the brain, resulting in clinically significant body weight reduction.
Interactive GLP-1 Estimation Model
Our clinical estimation algorithm projects weight loss benchmarks based on peer-reviewed STEP (Semaglutide) and SURMOUNT (Tirzepatide) clinical trial data.
Clinical Trial Weight Loss Benchmarks
In Phase 3 clinical trials, GLP-1 therapy demonstrated unprecedented weight loss percentage outcomes compared to traditional lifestyle interventions alone:
| Medication & Dose | Clinical Trial | Duration | Average Weight Loss % | 15%+ Weight Loss Achieving % |
|---|---|---|---|---|
| Semaglutide 2.4 mg (Wegovy) | STEP 1 Trial | 68 Weeks | 14.9% | 50.5% of Patients |
| Tirzepatide 15 mg (Zepbound) | SURMOUNT-1 Trial | 72 Weeks | 20.9% | 62.9% of Patients |
| Semaglutide 1.0 mg (Ozempic) | SUSTAIN Trials | 30 Weeks | 8.0% - 10.0% | 28.0% of Patients |
| Liraglutide 3.0 mg (Saxenda) | SCALE Trials | 56 Weeks | 8.0% | 33.1% of Patients |
Timeline & Phase-by-Phase Progress
- Weeks 1–16 (Dose Escalation Phase): Patients typically experience initial rapid loss of 5% to 8% body weight as doses are titrated upward monthly.
- Weeks 17–52 (Plateau & Maintenance Phase): Rate of weight loss stabilizes to approximately 0.5% to 1.0% per week, reaching 12% to 18% total loss.
- Weeks 52–72 (Maximal Efficacy Phase): Total weight loss percentage reaches peak median efficacy (15% for Wegovy, 20.9% for Zepbound).
Frequently Asked Questions
Q: What is the average weight loss percentage on GLP-1 medications?
Clinical trials indicate an average body weight loss percentage of 15% for Semaglutide (Wegovy 2.4 mg) over 68 weeks and up to 20.9% for Tirzepatide (Zepbound 15 mg) over 72 weeks when paired with lifestyle modifications.
Q: What happens if GLP-1 medication is discontinued?
The STEP 1 extension trial demonstrated that patients who stopped Semaglutide regained approximately two-thirds of their lost weight over 1 year. Long-term weight maintenance requires ongoing medical management and sustained lifestyle changes.
Medical References & Scientific Sources
- Wilding JPH, et al. (NEJM 2021): Once-Weekly Semaglutide in Adults with Overweight or Obesity (STEP 1 Trial). New England Journal of Medicine. DOI: 10.1056/NEJMoa2032183.
- Jastreboff AM, et al. (NEJM 2022): Tirzepatide Once Weekly for the Treatment of Obesity (SURMOUNT-1 Trial). New England Journal of Medicine. DOI: 10.1056/NEJMoa2206038.
- FDA Prescribing Information: Wegovy (semaglutide) injection and Zepbound (tirzepatide) injection official prescribing guidelines.
Dr. Sarah Jenkins, PhD, RD, CPT
Lead Clinical Dietitian & Exercise Physiologist specializing in GLP-1 medical weight loss nutrition, protein requirements, and metabolic adaptation.