GLP-1 Weight Loss Calculator
Average Weight Loss by Medication Over 68 Weeks
Projected weight loss for a 220 lb starting weight based on clinical trial averages
| Week | Wegovy | Ozempic | Mounjaro/Zepbound |
|---|---|---|---|
| Week 4 | 215 lbs (-2.3%) | 217 lbs (-1.4%) | 214 lbs (-2.7%) |
| Week 12 | 207 lbs (-5.9%) | 211 lbs (-4.1%) | 204 lbs (-7.3%) |
| Week 24 | 197 lbs (-10.5%) | 204 lbs (-7.3%) | 190 lbs (-13.6%) |
| Week 36 | 191 lbs (-13.2%) | 200 lbs (-9.1%) | 183 lbs (-16.8%) |
| Week 52 | 188 lbs (-14.5%) | 197 lbs (-10.5%) | 177 lbs (-19.5%) |
| Week 68 | 187 lbs (-15.0%) | 196 lbs (-10.9%) | 171 lbs (-22.3%) |
How We Calculate This
This glp-1 weight loss calculator uses established formulas and industry-standard data to provide accurate estimates.
- Enter your specific values into the calculator fields above
- Our algorithm applies the relevant formulas using your inputs
- Results are calculated instantly in your browser — nothing is sent to a server
- Review the detailed breakdown to understand how each factor affects your result
These calculations are estimates based on standard formulas. For critical decisions, always consult a qualified professional.
How to Convert Oven Recipes to Air Fryer
This calculator projects weight loss over time using average results from major GLP-1 receptor agonist clinical trials. It models the typical weight loss curve — rapid loss in months 1-6, gradual slowing through month 12, and plateau around months 15-18.
The basic rule:
- Wegovy (semaglutide 2.4mg): ~15% average body weight loss over 68 weeks (STEP 1 trial)
- Ozempic (semaglutide 1mg): ~10-12% body weight loss over 68 weeks (SUSTAIN trials, lower dose than Wegovy)
- Mounjaro/Zepbound (tirzepatide 15mg): ~22.5% body weight loss over 72 weeks (SURMOUNT-1 trial)
- Weight loss follows a logarithmic curve — fastest in early months, plateauing as the body adapts
These projections reflect population averages from clinical trials. About one-third of patients exceed the average, one-third hit the average, and one-third fall below. Diet, exercise, dose titration, and genetics all affect individual results. Discuss expectations with your prescriber.
When Would You Use This Calculator?
This glp-1 weight loss calculator is designed for anyone who needs quick, reliable estimates without complex spreadsheets or professional consultations.
- When you need a quick estimate before committing to a purchase or project
- When comparing different options or scenarios side by side
- When planning a budget and need to understand potential costs
- When you want to verify a quote or estimate you've received from a professional
- When teaching or learning about the concepts behind these calculations
Frequently Asked Questions
How much weight can I lose on Ozempic vs Wegovy?
Wegovy typically produces more weight loss than Ozempic because the maintenance dose is higher (2.4mg vs 1mg semaglutide). Clinical trials show about 15% body weight loss with Wegovy vs 10-12% with Ozempic over 68 weeks. Both are semaglutide — Wegovy is specifically FDA-approved for weight management at the higher dose.
Is Mounjaro or Zepbound more effective than Wegovy?
Clinical trial data suggests tirzepatide (Mounjaro/Zepbound) produces greater weight loss than semaglutide (Wegovy) — about 22.5% vs 15% body weight loss. The SURMOUNT-4 trial showed up to 26% loss in some cohorts. However, head-to-head trials are limited, and individual responses vary significantly.
When does weight loss plateau on GLP-1 medications?
Most patients see the fastest weight loss during months 2-6 after reaching the maintenance dose. Weight loss continues but slows through months 6-12, and typically plateaus around months 15-18. Some patients continue to lose small amounts beyond 18 months, especially with diet and exercise optimization.
What happens if I stop taking a GLP-1 medication?
The STEP 1 extension trial showed that patients regained about two-thirds of their lost weight within one year of stopping semaglutide. This is a key consideration — most experts recommend planning for long-term use. Lifestyle changes made during treatment can help reduce (but not eliminate) rebound.
How accurate is this calculator?
This calculator uses population averages from published clinical trials. About 33% of patients lose more than the average, 33% hit roughly the average, and 33% lose less. Factors including genetics, diet, exercise, starting BMI, dose achieved, and medication adherence all significantly affect individual outcomes.
What are common side effects of GLP-1 medications?
The most common side effects are gastrointestinal — nausea (30-45% of patients), vomiting, diarrhea, and constipation. These are usually worst during dose escalation and improve over time. Serious but rare risks include pancreatitis, gallbladder disease, and thyroid C-cell tumors (seen in animal studies). Always discuss risks with your doctor.