Updated June 2026 · ClinicalTrials.gov

RECRUITINGPhase 4INTERVENTIONAL

Pharmacotherapy in Conjunction With Lifestyle Counseling for Management of Weight Regain After Bariatric Surgery

Pharmacotherapy in Conjunction With Lifestyle Counseling for Management of Weight Regain After Bariatric Surgery (NCT05975580) is a Phase 4 interventional studying Obesity, sponsored by University of California, Irvine. RECRUITING as of the most recent ClinicalTrials.gov update. Talk to your doctor before contacting the trial site.

About This Trial

What Stage of Research Is This?

Phase 4 studies happen after a treatment has been approved by the FDA. They monitor long-term safety, real-world effectiveness, and any rare side effects that only emerge in larger populations over longer periods. Phase 4 results sometimes lead to label changes, additional warnings, or — rarely — withdrawal of approval.

This trial is currently recruiting participants. The sponsor has registered the study with ClinicalTrials.gov as actively enrolling, which means new applicants who meet the eligibility criteria can be considered for screening. Trial status can change between updates — confirm current recruiting status with the study contact before traveling for a screening visit.

Target enrollment of 120 participants puts this in the typical range for a Phase 2-style efficacy study or a moderate Phase 3 trial in a focused Obesity subpopulation. At this scale, the study has enough statistical power to detect a clear treatment effect but is not the largest cohort in the field.

Who May Be Eligible (Plain English)

Who May Qualify: 1. Male and female subjects aged 18-70 years 2. Had sleeve gastrectomy (SG) or Roux-en-Y gastric bypass (RYGB) at least 18 months ago 3. Weight regain of ≥5% relative to post-surgery nadir weight 4. Body mass index (BMI) ≥30 kg/m2 or ≥27 kg/m2 with weight-related comorbidities 5. Women of childbearing potential must be using appropriate contraception to avoid pregnancy throughout the study, and must have a negative pregnancy test at study entry 6. Must be able to provide written willing to sign a consent form Who Should NOT Join This Trial: 1. Type 1 diabetes 2. Insulin-dependent type 2 diabetes 3. Fasting plasma glucose (FPG) ≥240 mg/dL 4. Uncontrolled hypertension defined as systolic blood pressure (SBP) ≥150 mm Hg and/or diastolic blood pressure (DBP) ≥100 mm Hg on the average of three seated measurements after being at rest for at least 5 minutes 5. History of significant (as determined by the investigator) and unstable cardiovascular disease including coronary artery disease, arrhythmias, severe congestive heart failure, or stroke 6. Use of monoamine oxidase inhibitors, current or within 2 weeks 7. Hyperthyroidism or other significant thyroid disease 8. Angle-closure glaucoma 9. Agitated states 10. History of drug abuse within the past year 11. Known hypersensitivity or idiosyncrasy to sympathomimetic amines 12. Severe hepatic disease (non-alcoholic fatty liver disease or non-alcoholic steatohepatitis without portal hypertension or cirrhosis is acceptable) 13. End-stage renal disease 14. History of nephrolithiasis 15. Serum triglycerides ≥500 mg/dL 16. Cancer, not in remission, within the past 2 years except for adequately treated basal cell, squamous cell skin cancer, or in-situ cervical cancer 17. History of psychosis or bipolar disorder 18. Suicidal ideation or unstable/untreated major depressive disorder within the past year 19. Use of antidepressant medication that has not been at stable dose for at least 3 months ...See full criteria on ClinicalTrials.gov Always talk to your doctor about whether this trial is right for you.

These are translations of the protocol\'s inclusion and exclusion criteria, simplified for patients and caregivers. The original clinical text appears below. Eligibility is ultimately confirmed by the trial site\'s screening process — this summary is a starting point for a conversation with your doctor, not a final determination.

Original Eligibility Criteria

View original clinical language

Inclusion Criteria: 1. Male and female subjects aged 18-70 years 2. Had sleeve gastrectomy (SG) or Roux-en-Y gastric bypass (RYGB) at least 18 months ago 3. Weight regain of ≥5% relative to post-surgery nadir weight 4. Body mass index (BMI) ≥30 kg/m2 or ≥27 kg/m2 with weight-related comorbidities 5. Women of childbearing potential must be using appropriate contraception to avoid pregnancy throughout the study, and must have a negative pregnancy test at study entry 6. Must be able to provide written informed consent Exclusion Criteria: 1. Type 1 diabetes 2. Insulin-dependent type 2 diabetes 3. Fasting plasma glucose (FPG) ≥240 mg/dL 4. Uncontrolled hypertension defined as systolic blood pressure (SBP) ≥150 mm Hg and/or diastolic blood pressure (DBP) ≥100 mm Hg on the average of three seated measurements after being at rest for at least 5 minutes 5. History of significant (as determined by the investigator) and unstable cardiovascular disease including coronary artery disease, arrhythmias, severe congestive heart failure, or stroke 6. Use of monoamine oxidase inhibitors, current or within 2 weeks 7. Hyperthyroidism or other significant thyroid disease 8. Angle-closure glaucoma 9. Agitated states 10. History of drug abuse within the past year 11. Known hypersensitivity or idiosyncrasy to sympathomimetic amines 12. Severe hepatic disease (non-alcoholic fatty liver disease or non-alcoholic steatohepatitis without portal hypertension or cirrhosis is acceptable) 13. End-stage renal disease 14. History of nephrolithiasis 15. Serum triglycerides ≥500 mg/dL 16. Cancer, not in remission, within the past 2 years except for adequately treated basal cell, squamous cell skin cancer, or in-situ cervical cancer 17. History of psychosis or bipolar disorder 18. Suicidal ideation or unstable/untreated major depressive disorder within the past year 19. Use of antidepressant medication that has not been at stable dose for at least 3 months 20. Hospital Anxiety and Depression Scale (HADS) score of ≥11 for depression or anxiety items 21. Binge Eating Scale (BES) score of ≥27 22. Alcohol use disorder within the past year 23. Epilepsy 24. Currently taking phentermine or topiramate or the combination, or products containing these drugs 25. Currently taking stimulants (e.g., Attention Deficit Hyperactivity Disorder medications) 26. Current use of prescription or over-the-counter weight loss drugs or supplements 27. Taking prescription or over-the-counter drugs or products, which in the opinion of the PI, could be associated with significant effects on body weight 28. Planning additional bariatric surgery procedures in the next 13 months 29. History of revisional bariatric surgery (revisional surgery after adjustable gastric banding is acceptable) 30. Currently participating in another weight loss program or have plans to participate in the next 13 months 31. Smoking cessation within the previous 3 months or plans to quit smoking in the next 13 months 32. Pregnant or breastfeeding or planning pregnancy in the coming 13 months 33. History of, or any existing condition that, in the opinion of the Principal Investigator, would interfere with the study outcomes or place the subject at unacceptable risk by participating in the study

Treatments Being Tested

DRUG

Topiramate

Topiramate is an anticonvulsant (antiepilepsy) drug. IUPAC ID: 2,3:4,5-Bis-O-(1-methylethylidene)-beta-D-fructopyranose sulfamate

DRUG

Phentermine

Phentermine belongs to a class of drugs called anorectics, also known as appetite suppressants. IUPAC name 2-methyl-1-phenylpropan-2-amine

DRUG

Placebo

Placebo is an inactive substance.

Locations (1)

Trial sites listed on ClinicalTrials.gov for this study. Site activation status can vary — confirm with the specific site before traveling for a screening visit.

University of California Irvine Medical Center

Orange, California, United States

How to Talk to Your Doctor About This Trial

Bring the printable summary of this trial — including the NCT ID (NCT05975580), the sponsor (University of California, Irvine), and the key eligibility criteria — to your next appointment. Your doctor can review the inclusion and exclusion criteria against your medical history, lab values, and current treatments to assess whether you are likely to qualify. They can also help you weigh whether trial participation makes sense alongside your existing care plan.

Useful questions to walk through together: What does the trial protocol require beyond standard care? How long is the active treatment phase, and how long is follow-up? Are there study visits at sites I can reach? Who pays for the trial-specific procedures, and who pays for standard-of-care portions? See our 25 questions to ask about clinical trials guide for a more complete checklist.

Authoritative Sources

The official record for this trial lives on ClinicalTrials.gov — the federal registry maintained by the National Library of Medicine at NIH. For background on how this trial fits into the FDA approval pathway, see the FDA drug approval process. For oncology-specific guidance for patients considering trials, the National Cancer Institute publishes patient-oriented overviews. International trial registries are aggregated by the WHO ICTRP.

Frequently Asked Questions

What is the NCT05975580 clinical trial studying?

This is a randomized controlled trial employing a Sequential Multiple Assignment Randomized Trial (SMART) design to test whether pharmacotherapy, in conjunction with lifestyle counseling, can reverse weight regain after bariatric surgery. The full protocol is registered on ClinicalTrials.gov and includes the primary outcome measures, eligibility criteria, and study endpoints.

Who can participate in NCT05975580?

Eligibility for this trial depends on the specific inclusion and exclusion criteria set by the sponsor. The plain-English summary above translates the most important criteria into accessible language; the official clinical text is preserved in the collapsible section underneath. Whether you fit any specific trial is a medical decision your doctor needs to confirm — bring the trial information to your treating physician for a full review against your medical history.

How do I contact the trial site for NCT05975580?

Contact information registered with ClinicalTrials.gov is shown in the sidebar of this page. Before reaching out, confirm with your treating physician that this trial is appropriate for your situation. The trial site will then walk you through the screening process to determine final eligibility.

Is participating in a clinical trial safe?

Clinical trials in the United States are regulated by the FDA and overseen by Institutional Review Boards (IRBs) that review the protocol for safety. Risk varies by trial — Phase 1 studies test new treatments in humans for the first time, while Phase 3 trials use treatments that have already passed earlier safety screening. The informed consent document for any specific trial details the known risks and what to expect. Discuss those risks with your physician before deciding whether to participate.

Where can I verify the data on this page?

Every detail on this page comes directly from the ClinicalTrials.gov API. Click "View on ClinicalTrials.gov" in the sidebar to see the official, unmodified record. The federal record is always authoritative; this page is a structured presentation with a plain-English eligibility translation. For background on how clinical trials are regulated, see the FDA drug approval process documentation.

How This Page Is Built

Every field on this page is pulled directly from the ClinicalTrials.gov API v2 — no estimates, no proxies. The plain-English eligibility translation is generated from the original protocol text and reviewed for fidelity to the underlying clinical criteria. The original clinical text remains visible in the collapsible section above so users and clinicians can verify the translation. Read the full methodology for the data pipeline and known limitations.

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Source: ClinicalTrials.gov API v2 record for NCT05975580. Maintained by the National Library of Medicine at NIH. Public domain. Cite as: "TrialFinderData. NCT05975580. Data: ClinicalTrials.gov."

Medical disclaimer: This page is informational, not medical advice. Talk to your doctor about whether a clinical trial is right for you.

Last updated 2026-06-26 · Data from ClinicalTrials.gov.