How does the GLP-1 Weight Loss Timeline Calculator work?

Enter your age, sex, height, weight, whether you have type 2 diabetes, your GLP-1 medication (Mounjaro, Wegovy injection, or Wegovy pill), and treatment status. We apply published clinical trial percent-weight-loss curves to project how much weight you could lose by week 72, with key milestones at 3 months, 6 months, 1 year, and trial endpoint. If you are already on therapy, we back-calculate your baseline weight and project forward from today.

How much weight can you lose on Mounjaro?

In the SURMOUNT-1 trial, tirzepatide 15 mg produced an average of about 22.5% total body weight loss over 72 weeks. On an 80 kg starting weight, that is roughly 18 kg lost with a projected weight near 62 kg at week 72. Individual results vary with dose titration, adherence, diet, and activity.

How much weight can you lose on Wegovy injection?

Injectable semaglutide (Wegovy) trial curves in this calculator use on-treatment milestone data aligned with published STEP-style outcomes. Projections show gradual acceleration over the first several months as dose increases, with total loss building through 72 weeks. Higher-dose trials such as STEP UP report higher averages (~20.7% over 72 weeks on 7.2 mg)—your prescriber’s dose schedule affects your personal curve.

How much weight can you lose on the Wegovy pill?

Oral semaglutide (Wegovy pill) typically produces slower average weight loss than injectable semaglutide in trials such as OASIS. This calculator applies roughly 72% of the injectable loss rate at each milestone—a conservative planning estimate. Real-world results depend on taking the tablet daily on an empty stomach as directed.

Is Mounjaro more effective than Wegovy for weight loss?

In head-to-head trial comparisons, tirzepatide (Mounjaro) has generally shown higher average percent body weight loss than semaglutide (Wegovy) at comparable study durations. SURMOUNT-1 reported ~22.5% average loss for tirzepatide 15 mg versus lower averages in many semaglutide obesity trials. This calculator lets you switch medications to compare projections for your starting weight.

Does type 2 diabetes change GLP-1 weight loss projections?

Yes. People with type 2 diabetes often lose less total weight on GLP-1 medications than those without diabetes in the same trials—likely due to differences in insulin resistance, starting weight, and metabolism. This calculator adjusts projections when you select Yes: ~57% of the non-diabetes average for Mounjaro (SURMOUNT-2) and ~64% for Wegovy (STEP-2).

What if I haven't started GLP-1 yet?

Select "I haven't started yet" under treatment status. The calculator uses your current weight as your baseline and projects the full trial curve from week 0 to week 72, showing how much you could lose and your projected weight at each milestone.

What if I've just started GLP-1 (first 4 weeks)?

Select "I've just started (first 4 weeks)" and choose which week you are in (1–4). Early weeks are still in the dose titration phase, so percent loss is small. The calculator back-calculates your estimated starting weight and projects forward to trial endpoint from your current position on the curve.

What if I'm already on GLP-1 therapy?

Select "I'm already on it" and enter how many weeks you have been on your medication. We estimate your baseline weight at treatment start using the trial curve, then show remaining loss to week 72, updated milestones, and average weekly pace from now forward—not from day one.

What do the key milestones mean?

Milestones show projected weight and percent lost at 3 months (week 13), 6 months (week 26), 1 year (week 52), and trial endpoint (week 72). Percent lost is from your estimated baseline at treatment start. These are trial-average checkpoints—not guarantees of your exact progress on any given date.

What does "most people lose between X and Y kg" mean?

The range approximates typical spread around the trial-average endpoint loss—roughly the lower bound at ~70% of average loss and the upper bound at the average. Individual results fall above and below this band depending on adherence, dose, diet, exercise, sleep, and biology.

When does weight loss plateau on GLP-1?

Trial curves show the steepest loss in the first 3–6 months as dose titration completes, then a taper as the body approaches a new set point. Most published 72-week trials report average total loss near their endpoint plateau (e.g., ~22.5% for Mounjaro 15 mg in SURMOUNT-1). Plateau timing varies individually.

Can this calculator guarantee my results?

No. It uses clinical trial averages for educational planning only. Your actual loss may be faster, slower, or plateau at a different point. This is not medical advice—discuss expectations, dose, and side effects with your prescriber.

How is this different from the Weight Loss Goal & Timeline Calculator?

Our general Weight Loss Timeline Calculator uses a fixed weekly loss rate you choose (e.g., 0.5 kg/week) with calorie targets. This GLP-1 calculator uses medication-specific clinical trial curves, treatment status, and type 2 diabetes adjustments instead of a linear weekly rate.

Should I track protein while losing weight on GLP-1?

Yes—adequate protein (often 1.2–1.6 g/kg during active loss) and resistance training help preserve muscle when appetite is suppressed. Use our GLP-1 Protein & Muscle Preservation Calculator for daily gram targets and per-meal splits alongside this timeline tool.

Will I regain weight if I stop GLP-1?

Research suggests a significant share of weight lost on GLP-1 medications can be regained after stopping, especially without sustained nutrition and activity habits. Building protein intake, resistance training, and sleep routines during treatment supports long-term maintenance—discuss stopping plans with your clinician.

Can I export or share my projection?

Yes. After calculating, use the share button to export a PDF or copy a text summary of your projected loss, milestones, and interpretation for your prescriber, dietitian, or personal records.

Who should not rely on this calculator alone?

Anyone pregnant or breastfeeding, under 18, with a history of eating disorders, severe kidney or liver disease, or on insulin without medical supervision should not use this tool for treatment decisions. It does not replace prescribing advice, lab monitoring, or emergency care.

GLP-1 Weight Loss Timeline Calculator

See how much weight you could lose on Mounjaro, Wegovy injection, or Wegovy pill—using clinical trial on-treatment curves. Get a week-by-week projection with key milestones at 3 months, 6 months, 1 year, and trial endpoint.

Enter your details — results appear below after you calculate.

1 · Enter your details

Height, weight, age, and sex

Units

Sex

Age (years) *

Weight (kg) *

Height (cm) *

Do you have type 2 diabetes?

2 · Choose your medication

Mounjaro, the Wegovy injection, or the Wegovy pill

MounjarotirzepatideWegovy injectionsemaglutideWegovy pilloral semaglutide, daily tablet

Treatment status

I haven't started yetI've just started (first 4 weeks)I'm already on it

How this GLP-1 Weight Loss Timeline Calculator works

Enter your age, sex, height, weight, and whether you have type 2 diabetes. Choose your medication—Mounjaro (tirzepatide), Wegovy injection (semaglutide), or Wegovy pill (oral semaglutide)—and your treatment status (not started, just started in weeks 1–4, or already on therapy with weeks entered).

We apply published clinical trial percent-weight-loss curves— SURMOUNT-1 anchors for Mounjaro, on-treatment semaglutide milestones for Wegovy injection, and a scaled oral curve for the Wegovy pill—to project how much you could lose by week 72, your projected weight, a typical loss range, and key milestones at 3 months, 6 months, 1 year, and trial endpoint. Type 2 diabetes selections adjust projections using SURMOUNT-2 and STEP-2 subgroup ratios.

Results include interpretation, health considerations, recommendations, and PDF export—educational planning only, not medical advice. Pair with our GLP-1 Protein & Muscle Preservation, Weight Loss Timeline, or Calorie Deficit calculators.

GLP-1 Weight Loss Timeline Calculator

GLP-1 receptor agonists—including tirzepatide (Mounjaro, Zepbound) and semaglutide (Wegovy injection, Wegovy pill, Ozempic)—are among the most effective prescription options for chronic weight management. But the amount people lose varies with medication, starting weight, type 2 diabetes status, dose titration, and lifestyle. Our GLP-1 Weight Loss Timeline Calculator gives you a personalised week-by-week projection based on published clinical trial curves: projected loss at week 72, a typical loss range, and milestones at 3 months, 6 months, 1 year, and trial endpoint—with PDF export for planning with your care team.

Why a GLP-1-Specific Timeline Matters

GLP-1 medications do not produce instant or linear weight loss. Both Mounjaro and Wegovy start at lower doses and increase gradually over many weeks—weight loss typically accelerates after titration, then tapers toward a trial-average plateau by 12–18 months. Generic “lose 0.5 kg per week” calculators miss this curve. Knowing medication-specific milestones helps you set realistic expectations, track whether you are on pace with trial averages, and plan protein and strength training before rapid loss begins.

1What You Enter

Body & demographics

Age, sex, height, and body weight (metric or imperial)
Type 2 diabetes: Yes or No

Medication & treatment status

Mounjaro (tirzepatide), Wegovy injection (semaglutide), or Wegovy pill (oral semaglutide)
Treatment status: not started, just started (weeks 1–4), or already on therapy (weeks on medication)

2Formulas & Logic

Trial-based projection

Projected weight (week W) = baseline × (1 − trial % loss at W ÷ 100)

We interpolate percent body-weight lost between published trial milestones at weeks 0, 13, 26, 52, and 72. Mounjaro uses SURMOUNT-1 anchors (22.5% at week 72). Wegovy injection uses on-treatment semaglutide milestone data. Wegovy pill applies ~72% of the injectable loss rate (oral vs injectable trial differences).

Already on therapy

If you are on treatment, we back-calculate your estimated baseline weight at week 0 from your current weight and weeks on medication, then project remaining loss to week 72. Hero results show loss from today forward; milestones remain anchored to treatment start.

Type 2 diabetes adjustment

When you select Yes, percent loss at each week is scaled by trial subgroup ratios: ~57% of non-diabetes loss for Mounjaro (SURMOUNT-2 vs SURMOUNT-1) and ~64% for Wegovy (STEP-2 vs non-diabetes averages).

Typical range

“Most people lose between X and Y kg” uses ~70% of endpoint average loss as the low bound and the trial average as the high bound—a simplified planning band, not a formal statistical confidence interval.

Trial reference data (this calculator)

Medication	Trial basis	Duration	Endpoint avg loss
Mounjaro (15 mg)	SURMOUNT-1	72 weeks	~22.5%
Wegovy injection	STEP on-treatment curve	72 weeks	~13.2%*
Wegovy pill	OASIS-style (scaled)	72 weeks	~9.5%*

*Injectable and oral curves reflect milestone anchors used in this tool; higher-dose semaglutide trials (e.g. STEP UP 7.2 mg) report higher averages. Discuss your prescribed dose with your clinician.

3What Your Results Include

Projected total loss (kg and %) by trial endpoint (week 72)
Projected weight at week 72 and typical loss range
Key milestones: 3 months, 6 months, 1 year, trial endpoint—with weight, % lost, and kg lost
Starting weight, BMI, and average weekly loss pace
Trial-based interpretation and health considerations
Contributing factors (medication, T2D status, treatment week)
Recommendations including protein and muscle preservation
PDF export and share

Sample GLP-1 Weight Loss Projections

Example A — 80 kg, Mounjaro, no T2D

~18 kg (22.5%) lost by week 72 → ~62 kg. Month 3 ≈ 73.6 kg; month 6 ≈ 66.1 kg; year 1 ≈ 62.4 kg. Range ~12.6–18 kg.

Example B — 80 kg, Wegovy injection, no T2D

~10.6 kg (13.2%) lost by week 72 → ~69.4 kg. Slower titration early; most loss accumulates from month 3 onward. Pair with protein and resistance training.

Example C — 90 kg, Mounjaro, with T2D

T2D adjustment (~57% of non-diabetes curve) → ~11.5% endpoint loss (~10.4 kg) vs ~20.3 kg without diabetes on the same medication—illustrating why the diabetes toggle matters for planning.

Factors That Affect Your Results

Dose titration — Most loss accelerates after reaching maintenance dose (often week 16–32 depending on medication).
Adherence — Missed injections, delayed dose increases, or inconsistent oral dosing slow progress vs trial averages.
Diet & protein — Lower calorie intake drives loss, but adequate protein (1.2–1.6 g/kg during active loss) helps preserve muscle.
Physical activity — Resistance training supports lean mass and metabolic health during GLP-1 weight loss.
Type 2 diabetes — Trial subgroups with T2D consistently show lower average percent loss; enable the toggle for a adjusted projection.
Starting BMI — Higher BMI often means more absolute kg lost at the same percent, though percent loss is the primary trial metric.

Benefits of This GLP-1 Timeline Calculator

Medication-specific curves — Not a generic linear kg/week estimate.
Three GLP-1 options — Mounjaro, Wegovy injection, and Wegovy pill side by side for your weight.
Treatment status aware — Not started, early weeks, or already on therapy with weeks entered.
Type 2 diabetes adjustment — Subgroup-scaled projections when you select Yes.
Milestone planning — 3-, 6-, and 12-month checkpoints plus trial endpoint.
Exportable PDF — Share projections with your prescriber or dietitian.

GLP-1 Timeline vs General Weight Loss Timeline

Feature	GLP-1 Timeline (this page)	Weight Loss Goal & Timeline
Method	GLP-1 trial % loss curves	Fixed weekly kg loss + TDEE
Best for	Mounjaro, Wegovy injection, Wegovy pill users	Any calorie-deficit plan
Includes	T2D toggle, treatment status, trial milestones	Goal weight date, daily calorie target, BMI warnings

Important Limitations

This tool provides educational estimates based on clinical trial averages—not individualized medical advice, prescribing decisions, or a guarantee of results. Real progress depends on your prescribed dose schedule, adherence, side effects, diet quality, activity, sleep, genetics, and comorbidities. Trial participants received structured monitoring that real-world use may not replicate. Always work with your prescriber on medication choice, dose, goals, and when to seek care for nausea, dehydration, or other symptoms.

Frequently Asked Questions (FAQs)

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GLP-1 Weight Loss Timeline Calculator

1 · Enter your details

2 · Choose your medication

How this GLP-1 Weight Loss Timeline Calculator works

GLP-1 Weight Loss Timeline Calculator

Why a GLP-1-Specific Timeline Matters

1What You Enter

Body & demographics

Medication & treatment status

2Formulas & Logic

Trial-based projection

Already on therapy

Type 2 diabetes adjustment

Typical range

Trial reference data (this calculator)

3What Your Results Include

Sample GLP-1 Weight Loss Projections

Example A — 80 kg, Mounjaro, no T2D

Example B — 80 kg, Wegovy injection, no T2D

Example C — 90 kg, Mounjaro, with T2D

Factors That Affect Your Results

Benefits of This GLP-1 Timeline Calculator

GLP-1 Timeline vs General Weight Loss Timeline

Important Limitations

Frequently Asked Questions (FAQs)

How does the GLP-1 Weight Loss Timeline Calculator work?

How much weight can you lose on Mounjaro?

How much weight can you lose on Wegovy injection?

How much weight can you lose on the Wegovy pill?

Is Mounjaro more effective than Wegovy for weight loss?

Does type 2 diabetes change GLP-1 weight loss projections?

What if I haven't started GLP-1 yet?

What if I've just started GLP-1 (first 4 weeks)?

What if I'm already on GLP-1 therapy?

What do the key milestones mean?

What does "most people lose between X and Y kg" mean?

When does weight loss plateau on GLP-1?

Can this calculator guarantee my results?

How is this different from the Weight Loss Goal & Timeline Calculator?

Should I track protein while losing weight on GLP-1?

Will I regain weight if I stop GLP-1?

Can I export or share my projection?

Who should not rely on this calculator alone?

Related Calculators

Sarcopenia Risk Calculator

Body Mass Index (BMI) Calculator

Protein Target Calculator

GLP-1 Protein & Muscle Preservation Calculator

Total Daily Energy Expenditure (TDEE) Calculator

Calorie Deficit & Weight Loss Calculator

Weight Loss Goal & Timeline Calculator

Body Recomposition Calculator

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