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GLP-1 weight-loss timeline (estimates)

GLP-1 Weight Loss Timeline Calculator: How Long Until You Hit Goal Weight?

The GLP-1 Weight Loss Timeline Calculator estimates how many months it may take to reach your goal weight on Ozempic, Wegovy, Mounjaro, or Zepbound, based on STEP and SURMOUNT trial averages scaled to your starting weight and current dose. Use it to compare medications, match your weekly injection dose, and see BMI at goal alongside pounds left, with optional plateau adjustment for the slowdown many users see in months 4–6. Estimates only; not medical advice.

By Jeff Beem

Updated

01

Weight & goals

Units
Height (BMI at goal)
02

Medication

03

Estimates

Projected about 29.3 months, 127 weeks to goal, near 0.34 lbs per week on wegovy. Includes modeled plateau slowdown.

Projected timeline
To lose
40 lbs
BMI at goal
25.8
BMI
BMI=weight (kg)height (m)2\text{BMI} = \frac{\text{weight (kg)}}{\text{height (m)}^2}
Projection math
rate=start weight×(p%/100)Ttrial\text{rate} = \frac{\text{start weight} \times (p\% / 100)}{T_{\text{trial}}}

with plateau: rate × 0.7

weeks=⌈weight to loserate⌉\text{weeks} = \left\lceil \frac{\text{weight to lose}}{\text{rate}} \right\rceil
Trial reference

STEP: ~14.9% mean loss at this modeled dose. Individual results vary.

Plateau window: months 4 to 6

Notice

Estimates from published trial averages, not medical advice. Consult your clinician before changing medication.

Example: 220 lb → 180 lb, Wegovy 2.4 mg → ~29 months

The calculator defaults to 220 lb, 180 lb goal, 5 ft 10 in, Wegovy 2.4 mg, plateau adjustment on. That 40 lb gap projects to about 29 months (~127 weeks) on STEP’s 14.9% reference, with BMI near 25.8 at goal. Swap in your weight and dose; until you do, simply treat this as a worked sample.

Reading the projection

Trial averages vs your timeline

The STEP and SURMOUNT studies tracked large groups on semaglutide and tirzepatide and reported average percentage loss for each trial arm, not outcomes for any one person. Two participants can both sit near ~15% in the write-up and still lose very different pound totals, and this calculator scales the weekly rate to your starting weight. Use the month count to plan, not to pin down an exact finish date.

Match this week’s dose

Pick the dose on your pen today, not the maintenance mg you are titrating toward. Wegovy often steps 0.25 → 0.5 → 1.0 → 1.7 → 2.4 mg over roughly 16 weeks, and the calculator’s first 16 weeks already run at half the effective weekly rate to mirror that ramp. Early scale readings can look flat while appetite has already dropped.

Plateau toggle and BMI at goal

With plateau adjustment on, the effective weekly rate is multiplied by 0.7 for the whole projection (~29 months on these defaults). Turn it off and the same inputs land near 21 months. The toggle models the mid-course stall people describe around months 4–6; it is not a week-by-week replay of a plateau. BMI at goal uses height and target weight only. For protein and calories on therapy, use the GLP-1 Macro & Calorie Calculator.

GLP-1 weight loss timeline: Ozempic, Wegovy, Mounjaro, Zepbound

STEP averaged ~14.9% loss on Wegovy 2.4 mg over 68 weeks. Enter your weight and this week’s dose for a month count, with optional rate slowdown when plateau mode is on.

What the calculator returns

Published trial loss percentages become a weekly rate at your starting weight, then a month count to goal. The first 16 weeks run at half that effective rate to mirror dose titration; plateau mode multiplies the rate by 0.7 for the entire projection when enabled. You get months and weeks to goal, pounds left, BMI at goal, and the trial percentage tied to your drug and dose.
  • Same dose, different starting weights:
    On 2.4 mg Wegovy, someone at 350 lb losing 50 lb and someone at 220 lb losing 50 lb see different month counts because the trial rate scales with body weight. Run your pair in the form instead of copying a friend’s timeline.
  • Not medical advice:
    Trial averages only. Missed injections, pauses in titration, and comorbidities move real outcomes more than a spreadsheet. Talk to your prescriber before starting, stopping, or changing dose.
  • One thing worth knowing:
    Compare drugs by month count and trial % together. Judging a single weigh-in during titration or a water-weight week usually overreacts; eight- to twelve-week windows tell you more.

How the math works

Each dose tier carries a reference mean loss percentage and trial length (68 weeks for STEP semaglutide, 72 for SURMOUNT tirzepatide). Base weekly rate: rate=start weight×trial %trial weeks\text{rate} = \frac{\text{start weight} \times \text{trial \%}}{\text{trial weeks}}With plateau on, effective rate = rate × 0.7. Weeks to goal: weeks=16+⌈lbs to lose−8×effective rateeffective rate⌉\text{weeks} = 16 + \left\lceil \frac{\text{lbs to lose} - 8 \times \text{effective rate}}{\text{effective rate}} \right\rceil(first 16 weeks at half effective rate; if goal falls inside titration, the formula shortens). Hand check: 250 lb on Wegovy 2.4 mg, 40 lb to lose, no plateau → base rate ≈ 0.55 lb/week, about 82 weeks with titration included, not 73 from dividing 40 by 0.55 alone. Population averages; adherence, diet, activity, and genetics still dominate individual curves.

Ozempic, Wegovy, Mounjaro, and Zepbound

Semaglutide (Ozempic, Wegovy) and tirzepatide (Mounjaro, Zepbound) curb appetite by mimicking GLP-1; tirzepatide also hits GIP. Weight loss is mostly lower intake, not faster fat oxidation.
  • Wegovy:
    Obesity label up to 2.4 mg weekly; STEP ~14.9% mean over 68 weeks at that dose. Titration to 2.4 mg often takes ~16 weeks.
  • Ozempic:
    Same molecule at diabetes dose tiers, usually below 2.4 mg. Month estimates run gentler than Wegovy at maintenance; compare mg and trial %, not brand chatter.
  • Zepbound:
    Tirzepatide for obesity. SURMOUNT means run higher at 10–15 mg than semaglutide at 2.4 mg, so top-tier month counts can look shorter. Water shifts and mid-course stalls still flatten individual weeks.
  • Mounjaro:
    Tirzepatide for Type 2 diabetes with overlapping mg tiers. Off-label weight-loss talk is common; only your prescriber can say Mounjaro vs Zepbound for you.

Why progress stalls (months 4–6)

Plateau mode vs real stalls

Clinic notes often mention slower loss around months 3–6: lower energy expenditure at a smaller body weight, less early water drop, dose still climbing. The plateau toggle here applies a flat 0.7× rate multiplier for planning; it does not replay stall weeks one by one. Want a calorie-deficit comparison? Try the Calorie Calculator.
  • Metabolic adaptation:
    Smaller bodies burn fewer calories at rest; the same intake produces slower loss.
  • Water:
    Early rapid drops often include water; when that stabilizes, weekly loss looks smaller even if fat loss continues.
  • Dose and time:
    You may not be at maintenance mg yet. Stalls sometimes precede another drop after the next titration step.
  • What to do:
    Stay consistent, keep protein up, and loop your prescriber in before changing dose on your own.

STEP and SURMOUNT trial references

Where the percentages come from

Weekly rates in the form trace to published means. Summary:
  • STEP (semaglutide / Wegovy):
    STEP 1–5 in obesity at 2.4 mg: roughly 14–17% mean loss over 68–104 weeks depending on trial. Lower Ozempic doses show smaller means in diabetes trials.
  • SURMOUNT (tirzepatide / Zepbound):
    SURMOUNT-1 at 5, 10, 15 mg: ~15%, ~19.5%, and ~21% mean loss over 72 weeks respectively.
  • Limitation:
    Trial cohorts differ from every real-world patient. The form gives estimates for planning, not promises.

GLP-1 Weight Loss Timeline Calculator FAQ

How long does it take to lose 50 lbs on Wegovy?

There is no fixed answer. At STEP’s ~14.9% mean over 68 weeks, a 350 lb starting weight sheds about 52 lb in that window; 50 lb might land near the one-year mark if the curve held. At 220 lb, the same percentage is only ~33 lb in 68 weeks, so 50 lb takes longer. Turn plateau adjustment on and the month count stretches further. Plug your starting weight and dose into the form.

What is a GLP-1 plateau and how do I break it?

Many people see the scale stall around months 4–6 even while appetite stays down. Metabolic adaptation, less water weight, and still titrating dose all show up in clinic notes. Stay consistent with injections, keep protein and resistance training up, and talk to your prescriber before jumping doses. This calculator’s plateau toggle multiplies the weekly rate by 0.7 for the full timeline; it is a planning knob, not a read on whether your drug stopped working.

Is Mounjaro more effective than Ozempic for weight loss?

In head-to-head trial averages, tirzepatide ran higher than semaglutide. SURMOUNT-1 at 15 mg showed ~20.9% mean loss over 72 weeks; STEP 1 on Wegovy 2.4 mg was ~14.9% over 68 weeks. Mounjaro is labeled for Type 2 diabetes; Zepbound is the obesity brand on the same molecule. Ozempic and Wegovy are semaglutide (GLP-1 only); Mounjaro and Zepbound add GIP. Your prescriber picks the drug and dose for you, not the trial leaderboard.

How does starting weight affect my timeline?

The weekly rate scales with starting weight because trial percentages apply to body mass. Fourteen point nine percent of 300 lb is 45 lb; the same percentage on 180 lb is 27 lb. Two people on the same dose can therefore hit very different month counts to the same pound goal. Adherence and lifestyle still move the line; the form only models the trial-scaled rate.

Can I use this calculator for Rybelsus (oral semaglutide)?

Not cleanly. Rybelsus is daily oral semaglutide at lower mg than injectable Wegovy, and trial weight-loss means run below injectable 2.4 mg weekly. This tool covers injectable Ozempic, Wegovy, Mounjaro, and Zepbound only. If you are on Rybelsus, treat any Wegovy proxy here as a rough upper bound and ask your prescriber what to expect.

What happens to my weight if I stop GLP-1 medication?

Most trial follow-up and real-world reports show regain after stop, because appetite support drops off. Some people keep part of the loss with sustained diet and training; others need continued therapy or a taper plan. This calculator stops at goal weight on therapy and does not model regain. Long-term planning belongs with your clinician.

Data last reviewed against clinical trial updates: July 2026.

Sources & citations

References used for the calculation method and definitions. Links open in a new tab when available.

[1]
STEP 1 Trial: Semaglutide 2.4 mg for Weight Management (NEJM)

Pivotal New England Journal of Medicine trial demonstrating 14.9% mean weight loss with semaglutide 2.4 mg (Wegovy) over 68 weeks.

[2]
SURMOUNT-1 Trial: Tirzepatide for Obesity (NEJM)

Landmark NEJM trial showing 15–20.9% mean weight loss with tirzepatide (Mounjaro/Zepbound) over 72 weeks at varying doses.

[3]
STEP 5: Two-year effects of semaglutide (Nat Med)

Nature Medicine publication on longer-term semaglutide outcomes in adults with overweight or obesity.

[4]
FDA, Wegovy (semaglutide) prescribing information (NDA 215256)

Current FDA-approved labeling for Wegovy from Drugs@FDA (PDF).

[5]
FDA, Zepbound (tirzepatide) prescribing information (NDA 217806)

Current FDA-approved labeling for Zepbound from Drugs@FDA (PDF).

Medical Estimation Note

Estimates Only: This calculator provides estimates based on published clinical trial averages (STEP, SURMOUNT). It is not medical advice, diagnosis, or treatment.

Individual Variation: Results vary significantly between individuals. Your weight loss timeline, total loss, and response to medication may differ from trial averages.

Consult Your Provider: Consult your healthcare provider before starting or adjusting any GLP-1 medication. Do not change your dose based on calculator results.

Privacy First: All calculations are performed locally in your browser. No health data is stored or transmitted to any server.

© 2026 CalcRegistry Reference Last Logic Update: July 2026Free Online Utility Tools