Zepbound Weight Loss Results: How Much You Can Lose in 3 Months, a Year and Beyond

On average, 15.0% of body weight on 5 mg, 19.5% on 10 mg and 20.9% on 15 mg after 72 weeks, against 3.1% on placebo.1 Those are the results of SURMOUNT-1 (Study 1 on the label), a trial of 2,539 adults with obesity, or overweight plus a weight-related condition, and no diabetes.1,2

For the average person on 15 mg, who started at 105.6 kg (about 233 lb), a 20.9% loss works out to about 22 kg (about 49 lb).1 Your own result depends on your starting weight, dose and response.

Source: Zepbound label, Table 2, intention-to-treat population.1

All participants also got counseling on a reduced-calorie diet (about 500 kcal a day below needs) and at least 150 minutes of activity a week.1 Our weight loss projection tool applies these averages to your own starting weight.

Most people lose at least 5% of their body weight in the first 3 months: in a SURMOUNT-1 analysis, 82% of participants who took at least 75% of their doses had lost 5% or more by week 12.3 The other 18% lost less than 5% by week 12.3

At 3 months, most people are still on low doses. Week 12 is when the 10 mg group reached its target dose, and the 15 mg group did not reach 15 mg until week 20.3 The label's escalation period runs up to 20 weeks.1

A slow start does not predict failure. Of the people who had lost less than 5% at week 12, 90% reached at least 5% by week 72, and their mean weight loss at week 72 was 11.0%.3 It took them about 25 weeks on average to reach 5%.3 Our guide to how long Zepbound takes to work walks through the early weeks.

Yes. In every placebo-controlled weight trial on its label, Zepbound produced significantly more weight loss than placebo.1 The label reports four weight trials:

• SURMOUNT-1 (Study 1), adults without diabetes: −15.0% to −20.9% at 72 weeks, against −3.1% on placebo.1
• SURMOUNT-2 (Study 2), adults with type 2 diabetes: −12.8% on 10 mg and −14.7% on 15 mg at 72 weeks, against −3.2% on placebo.1
• SURMOUNT-3 (Study 3), after a 12-week intensive diet: people who had already lost 6.9% by dieting lost a further 18.4% on Zepbound over 72 weeks, while the placebo group regained 2.5%.1
• SURMOUNT-4 (Study 4), staying on or stopping: after 36 weeks on Zepbound, average loss was 20.9%.1

Weight loss was seen regardless of age, sex, race, ethnicity, starting BMI and diabetes status.1

In SURMOUNT-4, people switched to placebo after 36 weeks regained 14.0% of their weight over the next 52 weeks, while those who stayed on Zepbound lost a further 5.5%.1 The label approves Zepbound for long-term weight maintenance as well as for weight loss.1

In SURMOUNT-1 participants with prediabetes who stayed on treatment for 176 weeks, average weight loss was 12.3% on 5 mg, 18.7% on 10 mg and 19.7% on 15 mg, against 1.3% on placebo.4 Fewer people on tirzepatide developed type 2 diabetes: 1.3%, against 13.3% on placebo.4

Tirzepatide does not burn fat directly, but most of the weight it removes is fat: the Zepbound label says it lowers body weight with greater fat mass loss than lean mass loss.1 It works mainly by decreasing calorie intake, likely through effects on appetite.1

A body-scan (DXA) substudy of 160 SURMOUNT-1 participants measured this at week 72.5 On tirzepatide, fat mass fell 33.9% and lean mass 10.9%, alongside a 21.3% drop in body weight.5 About 75% of the weight lost was fat and 25% was lean mass, a split that was similar on placebo.5 Our article on GLP-1s, muscle loss and bone density covers what that lean-mass loss means.

Zepbound activates two gut-hormone receptors, GIP and GLP-1, which lowers appetite and calorie intake.1 It also slows stomach emptying, an effect that is largest after the first dose and fades over time.1 Tirzepatide's half-life is about 5 days, which allows one injection a week.1 For background, see what is Zepbound.

On average, yes, but with diminishing returns: going from 5 mg to 10 mg added 4.5 percentage points of weight loss in SURMOUNT-1, while going from 10 mg to 15 mg added 1.4.1 Side effects also rose with dose; vomiting affected 8% on 5 mg and 13% on 15 mg.1 Our Zepbound dosage guide explains how prescribers choose a maintenance dose, and the Zepbound side effects guide has the full table.

How fast do you lose weight on Zepbound? Most people in SURMOUNT-1 lost at least 5% by week 12, and average losses kept growing through week 72.3,1

Is Zepbound better than Mounjaro for weight loss? They are the same drug, tirzepatide, at the same doses. Zepbound is approved for weight reduction; Mounjaro is approved for type 2 diabetes.1 See Mounjaro vs Zepbound.

Is Zepbound or Wegovy better for weight loss? Our Wegovy vs Zepbound comparison sets the two labels' trial results side by side.

What if I am not losing weight on Zepbound? In SURMOUNT-1, 1.8% of adherent participants lost less than 5% by week 72.3 Our guide to not losing weight on a GLP-1 covers the common reasons.

Does Zepbound work without diet and exercise? The label approves Zepbound together with a reduced-calorie diet and more physical activity, and every trial included that counseling.1

Results only count if you can stay on the drug, so price matters. Our Zepbound cost guide and our cheapest Zepbound options show what each dose costs, and how to get tirzepatide online compares prescribing services. Run your own numbers with our Zepbound weight-loss estimator.

This article is for information only and is not medical advice. Trial averages are not a promise of individual results. Zepbound is a prescription drug with real risks and side effects, including a boxed warning for thyroid C-cell tumors.