What is the effect of Mounjaro® (tirzepatide) on waist circumference in adults with type 2 diabetes?

See important safety information, including boxed warning, in the attached prescribing information.

Waist Circumference Changes in SURPASS Studies

Mounjaro (tirzepatide) is a glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) receptor agonist indicated as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes (T2D) for once-weekly, subcutaneous administration.¹

In the SURPASS clinical trial program, change in waist circumference from baseline was assessed in adults with T2D treated with tirzepatide 5, 10, and 15 mg compared with placebo, semaglutide 1 mg, titrated insulin degludec, titrated insulin glargine, and titrated insulin lispro. A summary of waist circumference changes from the SURPASS-1 to -6 studies can be found in Table 1.^2-7

Table 1. Summary of Waist Circumference in SURPASS Studies^2-8

Waist Circumference (cm)a	Tirzepatide 5 mg	Tirzepatide 10 mg	Tirzepatide 15 mg	Comparatorb
SURPASS-1	n=121	n=121	n=120	n=113
Baseline	104.2	103.2	102.9	101.9
Waist circumference CFB	-5.7	-6.9	-7.2	-2.0
Difference vs placebo (95% CI)	-3.7 (-5.4, -2.1)c	-4.9 (-6.6, -3.2)c	-5.2 (-7.0, -3.5)c	--
SURPASS-2	n=470	n=469	n=469	n=468
Baseline	108.1	110.5	109.6	109.0
Waist circumference CFB	-6.9	-9.6	-9.9	-5.6
Difference vs semaglutide 1 mg (95% CI)	-1.3 (-2.4, -0.1)d	-3.9 (-5.1, -2.8)e	-4.3 (-5.4, -3.1)e	--
SURPASS-3	n=358	n=360	n=358	n=359
Baseline	110.7	110.3	109.8	110.7
Waist circumference CFB	-7.1	-9.5	-10.9	1.3
Difference vs insulin degludec (95% CI)	-8.4 (-9.5, -7.3)f	-10.8 (-12.0, -9.7)f	-12.2 (-13.3, -11.1)f	--
SURPASS-4	n=328	n=326	n=337	n=998
Baseline	109.4	109.2	108.4	108.3
Waist circumference CFB	-7.7	-7.9	-9.7	0.8
Difference vs insulin glargine (95% CI)	-8.5 (-9.7, -7.3)g	-8.7 (-9.9, -7.5)g	-10.5 (-11.7, -9.3)g	--
SURPASS-5	n=116	n=118	n=118	n=119
Baseline	112.2	111.9	111.3	109.9
Waist circumference CFB	-3.8	-7.4	-8.9	1.0
Difference vs placebo (95% CI)	-4.8 (-6.7, -2.9)c	-8.4 (-10.3, -6.5)c	-10.0 (-11.9, -8.1)c	--
SURPASS-6	n=242	n=238	n=236	n=708
Baseline	109.7	108.5	109.5	109.5
Waist circumference CFB	-5.7	-7.8	-9.6	2.1
Difference vs insulin lispro (95% CI)	-7.8 (-8.8, -6.8)h	-9.9 (-10.9, -8.9)h	-11.7 (-12.6, -10.7)h	-

Abbreviations: CFB = change from baseline; LSM = least squares mean; mITT = modified intention-to-treat.

Note: Efficacy estimand evaluates the treatment effect prior to discontinuation of the study drug without confounding effects of antihyperglycemic rescue therapy. All p-values for difference vs comparator were not controlled for type-1 error.

^a Data are LSM, mITT population (efficacy analysis set).

^b Comparator was placebo in SURPASS-1 and SURPASS-5 for 40 weeks. Comparator was semaglutide 1 mg once weekly in SURPASS-2 for 40 weeks. Comparator was titrated insulin degludec in SURPASS-3 for 52 weeks. Comparator was titrated insulin glargine in SURPASS-4 for 52 weeks. Comparator was titrated insulin lispro in SURPASS-6 for 52 weeks.

^c p<.001 vs placebo, not controlled for type 1 error.

^d p<0.05 vs semaglutide 1 mg, not controlled for type 1 error.

^e p<0.001 vs semaglutide 1 mg.

^f p<.001 vs insulin degludec, not controlled for type 1 error.

^g p<.001 vs insulin glargine, not controlled for type 1 error.

^h p<.001 vs insulin lispro, not controlled for type 1 error.

Enclosed Prescribing Information

MOUNJARO® (tirzepatide) injection, for subcutaneous use, Lilly

References

The published references below are available by contacting 1-800-LillyRx (1-800-545-5979).

1. Mounjaro [package insert]. Indianapolis, IN: Eli Lilly and Company; 2025.

2. Rosenstock J, Wysham C, Frías JP, et al. Efficacy and safety of a novel dual GIP and GLP-1 receptor agonist tirzepatide in patients with type 2 diabetes (SURPASS-1): a double-blind, randomised, phase 3 trial. Lancet. 2021;398(10295):143-155. https://doi.org/10.1016/S0140-6736%2821%2901324-6

3. Frías JP, Davies MJ, Rosenstock J, et al; SURPASS-2 Investigators. Tirzepatide versus semaglutide once weekly in patients with type 2 diabetes. N Engl J Med. 2021;385(6):503-515. https://doi.org/10.1056/NEJMoa2107519

4. Ludvik B, Giorgino F, Jódar E, et al. Once-weekly tirzepatide versus once-daily insulin degludec as add-on to metformin with or without SGLT2 inhibitors in patients with type 2 diabetes (SURPASS-3): a randomised, open-label, parallel-group, phase 3 trial. Lancet. 2021;398(10300):583-598. https://doi.org/10.1016/S0140-6736(21)01443-4

5. Del Prato S, Kahn SE, Pavo I, et al; SURPASS-4 Investigators. Tirzepatide versus insulin glargine in type 2 diabetes and increased cardiovascular risk (SURPASS-4): a randomised, open-label, parallel-group, multicentre, phase 3 trial. Lancet. 2021;398(10313):1811-1824. https://doi.org/10.1016/S0140-6736(21)02188-7

6. Dahl D, Onishi Y, Norwood P, et al. Effect of subcutaneous tirzepatide vs placebo added to titrated insulin glargine on glycemic control in patients with type 2 diabetes: the SURPASS-5 randomized clinical trial. JAMA. 2022;327(6):534-545. https://doi.org/10.1001/jama.2022.0078

7. Rosenstock J, Frías JP, Rodbard HW, et al. Tirzepatide vs insulin lispro added to basal insulin in type 2 diabetes: the SURPASS-6 randomized clinical trial. JAMA. 2023;330(17):1631-1640. https://doi.org/10.1001/jama.2023.20294

8. Data on file, Eli Lilly and Company and/or one of its subsidiaries.