Overweight , ObesityTIRZ-DOSE-NLNCT07504172
Real-world Effectiveness and Dosing Patterns of Tirzepatide in People With Obesity
An observational study of Overweight , Obesity and Obesity (Disorder), run by Radboud University Medical Center at 10 sites in Netherlands.
Trial summary
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. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Overweight , Obesity, Obesity (Disorder)
- What is being tested?
- Tirzepatide
- How many people
- 915 participants
- Where
- 10 sitesNetherlands
- Study dates
- 1 Apr 2026to 14 Oct 2026
- Phase
- Observational
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Outpatient clinic
Who may be able to join
- 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)
Who cannot join
- Pregnant women or pregnancy during treatment
- Previously treated for obesity (with pharmacotherapy, endoscopic treatment or metabolic-bariatric surgery)
- Patients with diabetes
Trial locations and contacts
10 sites in 1 country.
10 sites in 1 country
Netherlands10 sites
NOK clinics
Amsterdam
NOK clinics
Arnhem
NOK clinics
Beverwijk
NOK clinics
Gouda
NOK clinics
Heerlen
NOK clinics
Hoogeveen
NOK clinics
Nieuwegein
NOK clinics
Terneuzen
NOK clinics
The Hague
NOK clinics
Venlo
About this study
Official title: 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).
- Conditions
- Overweight , Obesity, Obesity (Disorder)
- Being tested
- Tirzepatide
- Keywords
- Obesity, Weightloss, Tirzepatide, Adults, Body composition, Dose escalation
- Medical subject headings
- Overweight, Obesity, Weight Loss
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
TirzepatideDrug
Also called Mounjaro
Initiating treatment with tirzepatide
| Study group | Role | What they receive |
|---|---|---|
| People with obesity | Adults Receives: Drug: Tirzepatide |
What is being measured
The primary outcome is the main question the study is designed to answer.
Weight change
%TWL= (start weight - 6 month weight/baseline weight)*100%
Measured: Baseline-6 months
Secondary outcomes (6)
Changes in body composition
Fat percentage (FP) and fat free mass (FFM)
Measured: Basline-6 months
Demographic and clinical characteristics
- Age
- Gender
- Treatment location
- Obesity associated diseases: hypertension, dyslipidaemia, sleep apnoea and osteoarthritis
- Previous lifestyle treatment for obesity
Measured: Baseline
Weight loss by maintenance dose
Maintenance dose (10mg and 15mg)
Measured: Baseline-6 months
Tirzepatide dosing patterns
Including the initial prescribed dose and subsequent dose escalations throughout the treatment course
Measured: Baseline-6 months
Weigth
in kilograms (kg)
Measured: Baseline-6 months
Height
in centimeters (cm)
Measured: Baseline-6 months
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted31 Mar 2026
- Study start1 Apr 2026
- Primary completion11 Jun 2026
- Study completion14 Oct 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for Overweight , ObesityStudies of the same condition, open and under way.
- More trials run by Radboud University Medical CenterThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Retrospective
- Enrolment
- 915 participants (actual)
Sponsor and investigators
- Lead sponsor
- Radboud University Medical Center
- Sponsor type
- University, hospital or other
- Collaborators
- Nederlandse Obesitas Kliniek
- Responsible party
- Sponsor
- Investigators
- Maria Hopman, MD, PhD, Principal investigator, Radboud University Medical Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07504172
- Sponsor's protocol ID
- 202508
- Acronym
- TIRZ-DOSE-NL
- Status last verified
- Feb 2026
- First submitted
- 20 Mar 2026
- Last updated
- 28 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
McGowan B, Ciudin A, Baker JL, Busetto L, Dicker D, Fruhbeck G, Goossens GH, Monami M, Sbraccia P, Martinez-Tellez B, Woodward E, Yumuk V. A systematic review and meta-analysis of the efficacy and safety of pharmacological treatments for obesity in adults. Nat Med. 2025 Oct;31(10):3317-3329. doi: 10.1038/s41591-025-03978-z. Epub 2025 Oct 2.
PubMed 41039116Jastreboff AM, le Roux CW, Stefanski A, Aronne LJ, Halpern B, Wharton S, Wilding JPH, Perreault L, Zhang S, Battula R, Bunck MC, Ahmad NN, Jouravskaya I; SURMOUNT-1 Investigators. Tirzepatide for Obesity Treatment and Diabetes Prevention. N Engl J Med. 2025 Mar 6;392(10):958-971. doi: 10.1056/NEJMoa2410819. Epub 2024 Nov 13.
PubMed 39536238Jastreboff AM, Aronne LJ, Ahmad NN, Wharton S, Connery L, Alves B, Kiyosue A, Zhang S, Liu B, Bunck MC, Stefanski A; SURMOUNT-1 Investigators. Tirzepatide Once Weekly for the Treatment of Obesity. N Engl J Med. 2022 Jul 21;387(3):205-216. doi: 10.1056/NEJMoa2206038. Epub 2022 Jun 4.
PubMed 35658024
Study at a glance
From the registry record, last updated by the sponsor on 28 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Real-world Effectiveness and Dosing Patterns of Tirzepatide: A Multicentre Retrospective Observational Study in the Netherlands
- ClinicalTrials.gov ID
- NCT07504172
- Acronym / sponsor ID
- TIRZ-DOSE-NL / 202508
- Conditions
- Overweight , Obesity, Obesity (Disorder)
- Keywords
- Obesity, Weightloss, Tirzepatide, Adults, Body composition, Dose escalation
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 915 participants (actual)
- Lead sponsor
- Radboud University Medical CenterUniversity, hospital or other
- Collaborators
- Nederlandse Obesitas Kliniek
- Study start
- 1 Apr 2026 (actual)
- Primary completion
- 11 Jun 2026 (actual)
- Study completion
- 14 Oct 2026 (actual)
- First posted
- 31 Mar 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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 design
- Observational model
- Cohort
- Time perspective
- Retrospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| People with obesity | – | Drug: TirzepatideAdults |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Outpatient clinic
Key inclusion criteria (2 listed)
- 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)
Key exclusion criteria (3 listed)
- Pregnant women or pregnancy during treatment
- Previously treated for obesity (with pharmacotherapy, endoscopic treatment or metabolic-bariatric surgery)
- Patients with diabetes
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| TirzepatideAlso: MounjaroInitiating treatment with tirzepatide | Drug | People with obesity |
Primary outcome
Weight change
Time frame: Baseline-6 months
%TWL= (start weight - 6 month weight/baseline weight)*100%
6 secondary outcomes
Changes in body composition
Time frame: Basline-6 months
Demographic and clinical characteristics
Time frame: Baseline
Weight loss by maintenance dose
Time frame: Baseline-6 months
Tirzepatide dosing patterns
Time frame: Baseline-6 months
Weigth
Time frame: Baseline-6 months
Height
Time frame: Baseline-6 months
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 28 Oct 2026.
- Background: PubMed 41039116McGowan B, Ciudin A, Baker JL, Busetto L, Dicker D, Fruhbeck G, Goossens GH, Monami M, Sbraccia P, Martinez-Tellez B, Woodward E, Yumuk V. A systematic review and meta-analysis of the efficacy and safety of pharmacological treatments for obesity in adults. Nat Med. 2025 Oct;31(10):3317-3329. doi: 10.1038/s41591-025-03978-z. Epub 2025 Oct 2.
- Background: PubMed 39536238Jastreboff AM, le Roux CW, Stefanski A, Aronne LJ, Halpern B, Wharton S, Wilding JPH, Perreault L, Zhang S, Battula R, Bunck MC, Ahmad NN, Jouravskaya I; SURMOUNT-1 Investigators. Tirzepatide for Obesity Treatment and Diabetes Prevention. N Engl J Med. 2025 Mar 6;392(10):958-971. doi: 10.1056/NEJMoa2410819. Epub 2024 Nov 13.
- Background: PubMed 35658024Jastreboff AM, Aronne LJ, Ahmad NN, Wharton S, Connery L, Alves B, Kiyosue A, Zhang S, Liu B, Bunck MC, Stefanski A; SURMOUNT-1 Investigators. Tirzepatide Once Weekly for the Treatment of Obesity. N Engl J Med. 2022 Jul 21;387(3):205-216. doi: 10.1056/NEJMoa2206038. Epub 2022 Jun 4.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Maria Hopman, MD, PhD principal investigator
Radboud University Medical Center
10 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Overweight , Obesity and Obesity (Disorder), run by Radboud University Medical Center at 10 sites in Netherlands.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 3 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 28 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 10 sites in Netherlands. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Weight change (time frame: Baseline-6 months). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07504172, which also lists 3 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 28 Oct 2026.