Do GLP-1 medicines affect breastmilk production and milk quality after pregnancy
Official title: Effects of GLP-1 RAs on Human Lactation Outcomes
Run by University of Colorado, Denver · NCT07720414 · Data updated 2026-11-12
This study will test whether weight loss from injected GLP-1 receptor agonists changes how much milk moms produce or the nutritional makeup of their breast milk.
Quick facts
| Study type | Observational |
|---|---|
| Sex | Women only |
| Enrollment | 18 (estimated) |
| Sponsor | University of Colorado, Denver Academic / other |
| Locations | 1 site (Aurora, Colorado) |
| Status | Recruiting |
| Started | July 2026 |
| Main results expected | June 2028 |
| Study ends | June 2028 |
| Registry record updated | July 22, 2026 |
| Trial ID | NCT07720414 on ClinicalTrials.gov |
Is this trial a fit for you?
✓Likely a good fit
Breastfeeding mothers of one or more infants who are planning or starting subcutaneous GLP-1 RA–based weight loss and have regular access to a breastpump.
✕Probably not a fit
Mothers not using GLP-1 RAs or not meeting pumping or weight-tracking requirements may not experience a benefit.
A plain-English reading of the study's rules. Only the study team can confirm whether you qualify.
What this trial studies
This observational study follows breastfeeding mothers who begin injectable GLP-1 receptor agonists for weight loss after pregnancy. Researchers will track milk production rates before and after starting treatment using serial breastpump milk expression and daily weight records. The study includes 2–3 morning visits over about 2.5–4.5 months to measure hourly milk output and milk composition. Participants must be breastfeeding, able to pump milk, and willing to share weight and milk samples. Results may clarify if GLP-1–driven weight loss influences lactation performance or milk nutrients.
Why it matters
Potential benefit: If successful, findings could inform weight-loss strategies for postpartum individuals without compromising milk production or milk quality.
How similar studies have gone: Previous studies on GLP-1 RAs and lactation are limited; this study explores a relatively novel area with scarce prior results.
Who can join: the full rules
Show full inclusion / exclusion criteria
Inclusion Criteria: * Breastfeeding mothers of single or multiple infants. * Milk removal at least 4x daily * Eligible for a GLP-1 RA administered subcutaneously (oral GLP-1 RAs contain absorption enhancers, which may drive accumulation in milk) * Access to a breastpump, if needed for maintaining breastfeeding behaviors. * Willingness to provide 1-3 oz of breastmilk per study visit. * Willingness to track and report body weight daily. * Willingness to maintain breastfeeding behaviors for the duration of the study. Exclusion Criteria: * Currently taking GLP-1 RA medication or other weight loss medication * Induced lactation, due to unknowns regarding the durability of the mammary gland's milk production after exogenous stimulation.
Where it's running
-
University of Colorado Anschutz School of Medicine
Aurora, Colorado, United States Recruiting
Study contacts
- Study coordinator: Jayne F Martin Carli, PhD
- Email: jayne.martincarli@cuanschutz.edu
- Phone: 303-724-3981
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How to take part
- Review the eligibility criteria above with your treating physician.
- Check the official listing on ClinicalTrials.gov for the latest contact details and recruitment status.
- Contact the study coordinator or principal investigator to ask for pre-screening. Pre-screening is free and never obligates you to enroll.