Where these projections come from
The numbers aren't guesses — they model the mean total body-weight loss reported in the drugs' pivotal trials: STEP-1 for Wegovy (semaglutide, ~15%), SURMOUNT-1 for Zepbound (tirzepatide, ~21%), и SCALE for Saxenda(liraglutide, ~8%). We fit those to a realistic curve that's slow during dose titration, steady through the middle months, и flattening toward a plateau.
Because these are averages, your real result can land well above or below the line. Dose, consistency, diet, sleep, и individual biology all move the number. The point is a grounded expectation, not a promise.
Tirzepatide vs semaglutide — the gap that matters
The single biggest driver of your projection is which molecule you take. Tirzepatide (Zepbound, Mounjaro) is a dual GLP-1/GIP agonist и produced materially more weight loss than semaglutide in trials. If the projection surprised you, that's usually why. Compare them directly on our 3-way comparison.
What happens next is up to a clinician
goodx doesn't prescribe or sell medication. We project, compare, и then send you to a licensed telehealth provider who handles the actual prescription. Take the 60-second quiz to get matched, or see which drug is cheapest per pound lost.
FAQ
How much weight will I lose on Wegovy or Ozempic?
In the STEP-1 trial, adults on semaglutide (Wegovy) lost an average of ~15% of body weight over 68 weeks. Ozempic (also semaglutide, but dosed for diabetes) tends to produce somewhat less for weight loss (~10-15%). Results vary widely by person, dose, и lifestyle. This calculator projects your loss using those trial averages.
How much weight can you lose on Zepbound or Mounjaro?
In SURMOUNT-1, adults on tirzepatide (the molecule in Zepbound and Mounjaro) lost an average of ~21% of body weight at the highest dose over 72 weeks — the most of any GLP-1-class drug to date. Individual results vary.
How fast does GLP-1 weight loss happen?
Loss is gradual. The first 4-8 weeks are usually slow because the dose is being titrated up. Most people see steady loss through months 3-9, then the rate slows as they approach a plateau around 12-18 months. This calculator shows that curve week by week.
Do you keep the weight off after stopping GLP-1?
Often not fully. In the STEP-4 withdrawal study, people who stopped semaglutide regained about two-thirds of their lost weight within a year. GLP-1s are generally considered long-term treatments for chronic weight management, not a short course. Discuss a maintenance plan with your prescriber.