How Much Weight You Can Lose on GLP-1

This tool estimates how long it may take to reach a goal weight using clinical trial average weight-change curves. It's a practical starting point, not a diagnosis or a substitute for medical advice—especially if you have kidney, heart, or metabolic conditions.

Tirzepatide & Semaglutide: SURMOUNT-5 trial (72 weeks), which directly compared tirzepatide to semaglutide. The data uses the on-treatment efficacy estimand (participants who remained on treatment).

Retatrutide — RUO (Research use only): Phase 2 clinical trial (48 weeks), which tested multiple doses including the 12 mg dose showing ~24% weight loss at 48 weeks.

It's the percentage of your starting weight (baseline) lost at a given time point. For example, if your baseline is 200 lb and the curve shows -10% at week 24, your projected weight at week 24 would be 200 × (1 − 0.10) = 180 lb.

Yes! Toggle "Already taking this medication?" and enter your current week number. The calculator will estimate your baseline weight and continue the projection forward from your current position on the curve, rather than restarting the early rapid-loss phase.

• It uses trial average trajectories (not individual predictions).
• It assumes weekly dosing and titration comparable to the trials.
• It assumes you remain on treatment for the modeled period.
• The SURMOUNT-5 curve aligns with the efficacy/on-treatment results.

It may not match exactly. Compounded products and different dosing schedules can lead to different outcomes, and clinical trial averages won't map perfectly. Use this as a general estimate and discuss your specific situation with a clinician.

No. This calculator provides estimates based on population averages from clinical trials. Talk to a licensed clinician about safety, dosing, side effects, and realistic goal setting for your individual situation.