Real-world Effectiveness and Dosing Patterns of Tirzepatide in People With Obesity (TIRZ-DOSE-NL)

March 25, 2026 updated by: Radboud University Medical Center

Real-world Effectiveness and Dosing Patterns of Tirzepatide: A Multicentre Retrospective Observational Study in the Netherlands

Tirzepatide is one of the new medications for the treatment of obesity. In clinical research people treated with Tirzepatide have weight loss up to 21%. But there is only a little bit of research showing the effect of Tirzepatide in clinical practice.

In this retrospective observational study the investigators will evaluate the effectiveness of tirzepatide in routine clinical practice among adults with obesity in the Netherlands.The main questions it aims to answer are:

  • How much weight do patients lose after six months of treatment with tirzepatide combined with lifestyle coaching?
  • How is the medication dosed in daily practice? Researchers will use data from electronic health records of patients in multiple outpatient locations of the Dutch Obesity Clinic (NOK, Nederlandse Obesitas Kliniek).

Study Overview

Status

Not yet recruiting

Conditions

Intervention / Treatment

Study Type

Observational

Enrollment (Estimated)

1700

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • Netherlands
      • Amsterdam, Netherlands
      • Arnhem, Netherlands
        • NOK clinics
      • Beverwijk, Netherlands
        • NOK clinics
      • Gouda, Netherlands
        • NOK clinics
      • Heerlen, Netherlands
        • NOK clinics
      • Hoogeveen, Netherlands
        • NOK clinics
      • Nieuwegein, Netherlands
        • NOK clinics
      • Terneuzen, Netherlands
        • NOK clinics
      • The Hague, Netherlands
      • Venlo, Netherlands
        • NOK clinics

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Non-Probability Sample

Study Population

Outpatient clinic

Description

Inclusion Criteria:

  • Adults (age ≥18 years old)
  • A BMI of ≥ 30 kg/m2 or a BMI ≥ 27 kg/m2 with at least one obesity complication (e.g., hypertension, dyslipidaemia)

Exclusion Criteria:

  • Pregnant women or pregnancy during treatment
  • Previously treated for obesity (with pharmacotherapy, endoscopic treatment or metabolic-bariatric surgery)
  • Patients with diabetes

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

Cohorts and Interventions

Group / Cohort
Intervention / Treatment
People with obesity
Adults
Drug: Tirzepatide
Initiating treatment with tirzepatide
Other Names:
  • Mounjaro

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Weight change
Time Frame: Baseline-6 months
%TWL= (start weight - 6 month weight/baseline weight)*100%
Baseline-6 months

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Changes in body composition
Time Frame: Basline-6 months
Fat percentage (FP) and fat free mass (FFM)
Basline-6 months
Demographic and clinical characteristics
Time Frame: Baseline
  • Age
  • Gender
  • Treatment location
  • Obesity associated diseases: hypertension, dyslipidaemia, sleep apnoea and osteoarthritis
  • Previous lifestyle treatment for obesity
Baseline
Weight loss by maintenance dose
Time Frame: Baseline-6 months
Maintenance dose (10mg and 15mg)
Baseline-6 months
Tirzepatide dosing patterns
Time Frame: Baseline-6 months
Including the initial prescribed dose and subsequent dose escalations throughout the treatment course
Baseline-6 months
Weigth
Time Frame: Baseline-6 months
in kilograms (kg)
Baseline-6 months
Height
Time Frame: Baseline-6 months
in centimeters (cm)
Baseline-6 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Radboud University Medical Center

Collaborators

Nederlandse Obesitas Kliniek

Investigators

  • Principal Investigator: Maria Hopman, MD, PhD, Radboud University Medical Center

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

April 1, 2026

Primary Completion (Estimated)

July 1, 2026

Study Completion (Estimated)

August 1, 2026

Study Registration Dates

First Submitted

March 20, 2026

First Submitted That Met QC Criteria

March 25, 2026

First Posted (Actual)

March 31, 2026

Study Record Updates

Last Update Posted (Actual)

March 31, 2026

Last Update Submitted That Met QC Criteria

March 25, 2026

Last Verified

February 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 202508

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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