Investigating how dopamine affects metabolism based on genetic differences in obesity

Dopamine Action on Metabolism Depending on Genetic Heterogeneity - a Randomized, Placebo-controlled Double Blind Study

PHASE2 · University Hospital Tuebingen · NCT03525002

This study is testing if a medication that affects dopamine can help people with obesity lose weight based on their genetic differences.

Quick facts

PhasePHASE2
Study typeInterventional
Enrollment150 (estimated)
Ages18 Years to 70 Years
SexAll
SponsorUniversity Hospital Tuebingen (other)
Locations3 sites (Cologne and 2 other locations)
Trial IDNCT03525002 on ClinicalTrials.gov

What this trial studies

This clinical trial aims to explore the relationship between dopamine signaling and obesity, particularly focusing on how genetic variations in the FTO gene influence this interaction. Participants with a body mass index (BMI) over 30 kg/m² will receive either the dopamine agonist bromocriptine or a placebo to assess its effects on weight loss. The study seeks to develop a personalized therapy approach for obesity based on individual genetic profiles. By understanding these interactions, the trial hopes to provide insights into more effective obesity treatments.

Who should consider this trial

Good fit: Ideal candidates for this study are adults with a BMI greater than 30 kg/m² who are willing to participate in the trial and provide informed consent.

Not a fit: Patients with diabetes mellitus or those who are pregnant or lactating may not benefit from this study.

Why it matters

Potential benefit: If successful, this study could lead to personalized obesity treatments that are more effective based on a patient's genetic makeup.

How similar studies have performed: While there have been preliminary studies indicating the interaction between FTO variants and dopamine signaling, this approach is relatively novel and not extensively tested in larger clinical settings.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Body mass index (BMI) between \>30 kg/m².
* Understand and voluntarily sign an informed consent document prior to any study related assessments/procedures.
* Females of childbearing potential (FCBP) must agree to utilize a reliable form of contraception simultaneously or practice complete abstinence from heterosexual contact while participating in the study.
* Males must agree to use a latex condom during any heterosexual contact while participating in the study and to refrain from donating semen or sperm while participating in this study.

Exclusion Criteria:

* Women during pregnancy and lactation.
* History of hypersensitivity to the investigational medicinal product or to any drug with similar chemical structure or to any excipient present in the pharmaceutical form of the investigational medicinal products.
* Participation in other clinical trials or observation period of competing trials up to 30 days prior to this study.
* Diabetes mellitus
* Treatment with Methyldopa, levodopa, dopamine agonists, metoclopramid, domperidon, glycerol nitrate, griseofulvin, azol-antimycotic drugs, macrolide-antibiotics, octreotide, orlistat, tamoxifen, liraglutide
* Any relevant cardiovascular disease, e.g. myocardial infarction, acute coronary syndrome, unstable angina pectoris, Percutaneous transluminal coronary angioplasty (PTCA), heart failure (NYHA III-IV), stroke or transient ischemic attack (TIA)
* Acute or chronic viral hepatitis or liver cirrhosis
* Impaired renal function, defined as estimated Glomerular Filtration Rate (eGFR) ≤ 60 ml/min (MDRD formula) as determined during screening.
* Medical history of cancer and/or treatment for cancer within the last 5 years.
* Claustrophobia
* Any other clinically significant major organ system disease at screening such as relevant gastrointestinal, neurologic, psychiatric, endocrine (i.e. pancreatic), hematologic, malignant, infection or other major systemic diseases making implementation of the protocol or interpretation of the study results difficult.
* Presence of any contraindication for the conduct of an MRI investigation, such as cardiac pacemakers, ferromagnetic haemostatic clips in the central nervous system, metallic splinters in the eye, ferromagnetic or electronically operated active devices like automatic cardioverter defibrillators, cochlear implants, insulin pumps and nerve stimulators, prosthetic heart valves etc.
* hyperthyroidism
* therapy refractary hypertension
* peripheral arterial disease
* Parkinson´s disease
* Known current presence or history of one of the following psychiatric diseases: depression, mania, anxiety and panic disorder, obsessive-compulsive disorder, schizophrenia, psychosis, addiction
* pituitary disease
* treatment with bromocriptine during 12 month before entering the trial
* dementia
* gastric or intestinal ulcer
* Persons with limited temperature sensation and / or elevated sensitivity to warming of the body
* Persons with a hearing disorder or a increased sensitivity for loud noises
* smoking
* Refusal to get informed of unexpected detected pathological findings

Any other clinical condition that would jeopardize subjects' safety while participating in this clinical trial.

Where this trial is running

Cologne and 2 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.

View on ClinicalTrials.gov →

Conditions: Obesity

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.