Tirzepatide in Adults With Type 1 Diabetes: A Phase 2 Randomized Placebo-Controlled Clinical Trial.

Snaith JR, Frampton R, Samocha-Bonet D, Greenfield JR

Diabetes care1 Jan 2026Cited by 26 (Europe PMC)

PMID41264593PMCIDPMC12719702DOI10.2337/dc25-2379PepBankPUB-41264593

Summary

The text of this summary is not shown here, because the article license does not allow reuse. Read it at the source (opens in a new tab)

Text rights: Publisher copyright. Results still quote short attributed sentences.

Results from this study6

6 results from studies that gave the peptide. 6 results from people.

01HumanRandomized controlled trialEfficacy outcome
In adults with type 1 diabetes and obesity, tirzepatide reduced weight by 10.3 kg versus 0.7 kg with placebo over 12 weeks (treatment difference -8.7 kg).
In plain wordsIn adults with type 1 diabetes and obesity, tirzepatide produced much more weight loss than placebo over 12 weeks.
Peptide
Tirzepatide
Outcome
DecreaseBody weight change at 12 weeks
Study
n: not reported in source
Comparator
Placebo
Analysis
Primary
Outcome group
Body weight · Metabolic and weight
Studied dose
2.5 mg for 4 weeks, 5.0 mg for 8 weeks · subcutaneous · 12 weeksAs given in this study (human).
Measurements
weight change
−10.3 kg
tirzepatide
weight change
−0.7 kg
placebo
treatment difference
−8.7 kg
tirzepatide vs placebo
weight loss
8.8%
tirzepatide
Source sentences
Summary
After 12 weeks, the mean change in weight was -10.3 kg (95% CI -12.8 to -7.7 kg) in the tirzepatide group and -0.7 kg (95% CI -1.4 to 2.8 kg) in the placebo group, with an estimated treatment difference of -8.7 kg (95% CI -12.0 to -5.5 kg; P < 0.0001), representing 8.8% weight loss.
3 context sentences(design, population, supporting numbers)
Summary · context
The primary end point was change in body weight at 12 weeks.
Summary · context
We conducted a 12-week, phase 2, double-blind, placebo-controlled trial in adults with type 1 diabetes and BMI >30 kg/m2.
Summary · context
Participants were randomized to once-weekly subcutaneous tirzepatide (2.5 mg for 4 weeks, 5.0 mg for 8 weeks) or placebo.
Report a problemFND-4126459301
02HumanRandomized controlled trialEfficacy outcome
In adults with type 1 diabetes and obesity, 100% of tirzepatide participants lost 5% or more of weight versus 9% with placebo.
In plain wordsIn adults with type 1 diabetes and obesity, everyone on tirzepatide lost at least 5% of weight, versus few on placebo.
Peptide
Tirzepatide
Outcome
IncreaseWeight loss of 5% or more
Study
n: not reported in source
Comparator
Placebo
Outcome group
Body weight · Metabolic and weight
Studied dose
2.5 mg for 4 weeks, 5.0 mg for 8 weeks · subcutaneous · 12 weeksAs given in this study (human).
Measurements
responders
100%
tirzepatide
responders
9%
placebo
Source sentences
Summary
In the tirzepatide group, 100% and 45% of participants experienced weight loss of ≥5% and ≥10% respectively, compared with 9% and 0% in the placebo group.
2 context sentences(design, population, supporting numbers)
Summary · context
We conducted a 12-week, phase 2, double-blind, placebo-controlled trial in adults with type 1 diabetes and BMI >30 kg/m2.
Summary · context
Participants were randomized to once-weekly subcutaneous tirzepatide (2.5 mg for 4 weeks, 5.0 mg for 8 weeks) or placebo.
Report a problemFND-4126459302
03HumanRandomized controlled trialEfficacy outcome
In adults with type 1 diabetes and obesity, 45% of tirzepatide participants lost 10% or more of weight versus 0% with placebo.
In plain wordsIn adults with type 1 diabetes and obesity, many more people on tirzepatide than on placebo lost at least 10% of weight.
Peptide
Tirzepatide
Outcome
IncreaseWeight loss of 10% or more
Study
n: not reported in source
Comparator
Placebo
Outcome group
Body weight · Metabolic and weight
Studied dose
2.5 mg for 4 weeks, 5.0 mg for 8 weeks · subcutaneous · 12 weeksAs given in this study (human).
Measurements
responders
45%
tirzepatide
responders
0%
placebo
Source sentences
Summary
In the tirzepatide group, 100% and 45% of participants experienced weight loss of ≥5% and ≥10% respectively, compared with 9% and 0% in the placebo group.
2 context sentences(design, population, supporting numbers)
Summary · context
We conducted a 12-week, phase 2, double-blind, placebo-controlled trial in adults with type 1 diabetes and BMI >30 kg/m2.
Summary · context
Participants were randomized to once-weekly subcutaneous tirzepatide (2.5 mg for 4 weeks, 5.0 mg for 8 weeks) or placebo.
Report a problemFND-4126459303
04HumanRandomized controlled trialEfficacy outcome
In adults with type 1 diabetes and obesity, tirzepatide improved HbA1c versus placebo (mean difference -0.4%; P = 0.05).
In plain wordsIn adults with type 1 diabetes and obesity, tirzepatide improved HbA1c slightly more than placebo.
Peptide
Tirzepatide
Outcome
DecreaseHbA1c change
Study
n: not reported in source
Comparator
Placebo
Outcome group
Glycemic control · Metabolic and weight
Studied dose
2.5 mg for 4 weeks, 5.0 mg for 8 weeks · subcutaneous · 12 weeksAs given in this study (human).
Measurements
HbA1c mean difference
−0.4%
tirzepatide vs placebo
Source sentences
Summary
Tirzepatide improved HbA1c (mean difference -0.4% [95% CI -0.7 to 0.0%] vs. placebo; P = 0.05)
2 context sentences(design, population, supporting numbers)
Summary · context
We conducted a 12-week, phase 2, double-blind, placebo-controlled trial in adults with type 1 diabetes and BMI >30 kg/m2.
Summary · context
Participants were randomized to once-weekly subcutaneous tirzepatide (2.5 mg for 4 weeks, 5.0 mg for 8 weeks) or placebo.
Report a problemFND-4126459304
05HumanRandomized controlled trialEfficacy outcome
In adults with type 1 diabetes and obesity, tirzepatide reduced total daily insulin dose by 24.2 units/day versus 0.3 units/day with placebo.
In plain wordsIn adults with type 1 diabetes and obesity, tirzepatide cut daily insulin dose far more than placebo.
Peptide
Tirzepatide
Outcome
DecreaseTotal daily insulin dose
Study
n: not reported in source
Comparator
Placebo
Outcome group
Glycemic control · Metabolic and weight
Studied dose
2.5 mg for 4 weeks, 5.0 mg for 8 weeks · subcutaneous · 12 weeksAs given in this study (human).
Measurements
insulin dose change
−24.2 units/day
tirzepatide
insulin dose change
−0.3 units/day
placebo
difference vs placebo
−35.1%
tirzepatide
Source sentences
Summary
reduced total daily insulin dose (-24.2 units/day tirzepatide and -0.3 units/day placebo; difference from baseline vs. placebo -35.1% [95% CI -46.5 to -21.3%; P = 0.0002]).
2 context sentences(design, population, supporting numbers)
Summary · context
We conducted a 12-week, phase 2, double-blind, placebo-controlled trial in adults with type 1 diabetes and BMI >30 kg/m2.
Summary · context
Participants were randomized to once-weekly subcutaneous tirzepatide (2.5 mg for 4 weeks, 5.0 mg for 8 weeks) or placebo.
Report a problemFND-4126459305
06HumanRandomized controlled trialSafety outcome
In adults with type 1 diabetes and obesity, there were no significant adverse events in either group.
In plain wordsIn adults with type 1 diabetes and obesity, no significant side effects occurred in either group.
Peptide
Tirzepatide
Outcome
No significant changeAdverse events
Study
n: not reported in source
Comparator
Placebo
Outcome group
Adverse events · Whole body
Studied dose
2.5 mg for 4 weeks, 5.0 mg for 8 weeks · subcutaneous · 12 weeksAs given in this study (human).
Source sentences
Summary
There were no significant adverse events in either group.
2 context sentences(design, population, supporting numbers)
Summary · context
We conducted a 12-week, phase 2, double-blind, placebo-controlled trial in adults with type 1 diabetes and BMI >30 kg/m2.
Summary · context
Participants were randomized to once-weekly subcutaneous tirzepatide (2.5 mg for 4 weeks, 5.0 mg for 8 weeks) or placebo.
Report a problemFND-4126459306

AI wrote and checked these results. AI can make mistakes, so check important results against the source.

Registered trials1

Trials this study reports on, or that list this study as a reference. Registry data from ClinicalTrials.gov.

1 trial · 1 ongoing · source ClinicalTrials.gov (opens in a new tab)

RecruitingPhase 2NCT06820281

Acute Metabolic Effects of Tirzepatide in Type 1 Diabetes

Victor Chang Cardiac Research Instituten = 447 Jul 2026 to est. 31 Dec 2027

Type 1 Diabetes Mellitus

Trial page ClinicalTrials.govUpdated 16 Sept 2026

Version history

PepBank keeps every version of the data on this study. Status changes from Retraction Watch, Europe PMC and Crossref are listed with their source.

Version 2Current
12 Oct 2026, 12:10 UTC
Study results updated
Version 1
9 Oct 2026, 03:07 UTC
First added · source update from Europe PMC

Subjects

Terms as the source lists them.

Publication types

MeSH terms

PepBank is a research reference. Talk to a doctor before you use any peptide.