Acute Metabolic Effects of Tirzepatide in Type 1 Diabetes

What Was Tested

This registered phase 2 trial tested Tirzepatide.

This study will examine the effects of Tirzepatide (TZP), a glucagon-like peptide 1 (GLP1) - gastric inhibitory peptide (GIP) co-agonist, on metabolism in type 1 diabetes (T1D).

These measures will be performed prior to, and after 6 weeks of treatment with TZP or placebo.

It had two arms (groups): one (experimental) and Placebo (placebo comparator).

Administered subcutaneously.

Administered subcutaneously.

The registry classes the interventions as drug.

More on the Plan

TIRTLE2 will employ the 'gold standard' hyperinsulinemic-euglycemic and hypoglycemic clamps, in conjunction with complementary analyses of the effects of TZP on metabolism across multiple physiological states.

Who Took Part

The registry lists 44 planned participants were the target.

It was open to people of any sex aged from 18 years up to 70 years.

Healthy volunteers were not accepted; participants needed the condition being studied.

Examples of who could join: Age 18-70 years. BMI ≥ 25 kg/m2. Insulin delivery using an automated insulin delivery system. At least 2 years since diagnosis of type 1 diabetes.

The full record lists 5 inclusion and 11 exclusion criteria; among the exclusions: hypoglycemic unawareness or severe hypoglycemia last 6 months; history of seizure disorder; history of weight loss surgery.

How the Study Was Run

It was run as a randomized, parallel-group and quadruple-blind study.

Random assignment meant chance, not the researchers, decided who got Tirzepatide and who got the comparison, which limits bias.

Groups ran in parallel: each of the participants stayed in one arm throughout.

Neither the participants nor the staff measuring them knew who was on Tirzepatide, so expectations could not easily colour the readings.

Those kept unaware of assignments: participant, care provider, investigator and outcomes assessor.

It started in 2026-07-07 with completion listed for 2027-12-31.

It ran at 1 site in Australia.

Its stated primary purpose is treatment.

What Was Measured

The main thing measured (primary outcome): Whole-body insulin sensitivity (time frame: 6 weeks).

It also tracked 16 secondary outcomes, for example Prandial glucagon secretion, Glucagon response to hypoglycemia, % Time level 2 hypoglycemia, % Time level 1 hypoglycemia, Resting energy expenditure (REE) and Overnight growth hormone curve.

What This Means in Plain Language

Put simply, this is a phase 2, randomized trial of Tirzepatide in 44 people.

It is still recruiting; no results are posted to the registry yet, so nothing here describes outcomes.

More context: the Tirzepatide compound page, all human trials.