An observational study in Lactation and Weight Loss, sponsored by University of Colorado, Denver. Recruiting at 1 site in United States. Open to female participants, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-07-22.
Sponsored by University of Colorado, Denver · Observational
Among 250 studies in Breast Feeding with a site in United States — 43 open to participants now, 48 under way, none of them phase 3. Breast Feeding · United States.
Among the 250 studies in Breast Feeding with a site in United States, this one is the 42nd largest by planned enrollment of the 49 observational ones, is one of 13 that started in 2026, is one of 49 observational ones, reaches primary completion later than 32 of the 47 other live ones, and was the 246th registered.
1,081 studies on the registry are indexed under Breast Feeding; 217 are open to participants now.
This study's planned enrollment of 18 is below the median of 158 across 207 observational studies indexed under Breast Feeding.
Browse Breast Feeding studies →43 of the 250 studies in Breast Feeding with a site in United States are open now, in 7 countries. Each count lists the studies.
Of the 126 Breast Feeding studies recruiting now, 66 (52%) set no upper age limit and 58 (46%) stop at 75 or younger; 54 take children under 18; 76 take healthy volunteers.
This study: female · healthy volunteers too.
The full table on the hub →250 studies; the count open now beside each. This study's row is marked.
First in 2000; this study’s year is marked. 13 started in 2026.
Median enrollment 82 across the 201 interventional studies, 88 across the 49 observational. Of the 180 that completed or were terminated, 46 (26%) have results posted.
22 of 250 have an industry lead sponsor. The 10 most frequent:
University of Colorado, Denver is the lead sponsor of 1,543 studies on the registry; 317 are open to participants now.
Of its 147 completed or terminated interventional studies of FDA-regulated products, 92 (63%) have results posted.
University of Colorado, Denver has 6 studies filed under Breast Feeding — fewer than ten, so there is no comparison to draw.
16 of the studies in Breast Feeding with a site in United States that are under way reach primary completion within a year, 0 of them phase 3. Phase 3 first, then by date:
| Study | Primary completion |
|---|---|
| NCT07351799Mayo ClinicMindfulness and Meditation Based Lactation Education on Maternal Breastmilk in the Neonatal ICU | 2026-11-02 |
| NCT07176793University of California, DavisPregnancy and Postpartum Breastfeeding Support for Patients With Gestational Diabetes | 2026-12-30 |
| NCT05457972University Hospitals Cleveland Medical CenterPostpartum Vaginal Estrogen for Breastfeeding Patients | 2026-12-31 |
| NCT06107933Johns Hopkins Bloomberg School of Public HealthDevelopmental Impacts of Microplastics Exposure in Early Life | 2026-12-31 |
| NCT05441709Endeavor HealthFurthering Equity Through Infant Feeding EDucation and Support | 2026-12-31 |
Among the 250 studies in Breast Feeding with a site in United States, from their registry updates:
There is increasing interest in using GLP-1 Receptor Agonist (GLP-1 RA) medications after pregnancy. This study is designed to determine if these medications affect breastmilk production or the nutritional makeup of breastmilk.
The main questions the study will address are:
Researchers will assess milk production rates before and after mothers begin taking injected GLP-1 RA medications to decrease their body weight. Weight loss will be confirmed with 7-day body weight averages.
Participants will:
During each visit, participants will:
Breastfeeding mothers willing to attend study study visits in Aurora, CO.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Breastfeeding mothers who have been prescribed, but have not started, an injected GLP-1RA (these patients have an indication for GLP-1 RA treatment (BMI ≥27 kg/m2 with at least one comorbidity (prediabetes, diabetes, metabolic syndrome, obstructive sleep apnea, hypertension, dyslipidemia, cardiovascular disease, heart failure, chronic kidney disease, metabolic dysfunction-associated steatohepatitis, atrial fibrillation, venous thromboembolic disease, osteoarthritis, polyendocrine metabolic ovarian syndrome), or BMI ≥30 kg/m2)) and who are committed to sustaining breastfeeding habits (frequency and volume of milk removal) for the duration of the study period.
Drug: Injected GLP-1 Receptor Agonists and Dual Agonists
Participants are prescribed this medication by their care provider(s) as part of their postnatal clinical care, including but not limited to semaglutide and tirzepatide. The investigators do not provide, manage, or assign the medication.
This study also gives Semaglutide, Tirzepatide. No intervention listed here names it: that was found by reading the record.
Hourly milk production rate
Milk production rate (in grams per hour) will be assessed using a standardized milk expression protocol.
Time frame: From one week before until a maximum of 2 months after beginning GLP-1RA treatment. This timeframe will restart if their dosage is increased.
Milk macronutrient composition
Milk macronutrient composition will be assessed using the Miris Human Milk Analyzer.
Time frame: From one week before until a maximum of 2 months after beginning GLP-1RA treatment. This timeframe will restart if the dosage is increased.
Plan to share: Yes — De-identified individual participant data and leftover biological samples may be deposited into public or restricted-access data banks, or distributed directly to external researchers for future study without additional participant consent. Data and specimens will be stripped of names and direct identifiers prior to sharing or repository submission. Recipients of these assets may include researchers working at other universities, government agencies, or private industry. Future research utilizing this data may focus on obesity, weight loss treatments, or other related medical conditions. While data are de-identified to protect privacy, absolute protection against re-identification cannot be guaranteed, and broad data sharing may involve unknown risks.
Time frame: Data will be made available following the primary completion of the study and publication of main results, or upon deposition into designated data repositories.
Access criteria: Data and leftover samples will be accessible to qualified researchers across academic, government, and private industry sectors. Access to data housed in restricted data banks will be governed by the specific repository's data access committee. Direct requests to the study investigators will require a scientifically valid proposal.
No publications or documents are linked to this record.
Start is estimated for Jul 2026; primary completion for Jun 2028, 23 months later.
Of 86 non-industry observational studies under Breast Feeding, half reached primary completion within 31 months of starting (the median), counting those still running; a quarter within 19 and three quarters within 54. This study's planned 23 months is below that.
Counting every sponsor, half of 96 studies reached it within 33 months; a quarter within 19 and three quarters within 73.
How these figures are worked out, and which studies are left out of them.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
Contact study teamGet an email when the registry record changes — status, dates, results — or when someone posts here.
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University of Colorado, Denver →