Can you take pegvisomant while breastfeeding?
What LactMed says
The National Library of Medicine’s own summary, quoted in full. We do not write a verdict of our own on this question, and we do not compress theirs into a label.
Limited data indicate that pegvisomant is poorly excreted into breastmilk. Because pegvisomant is not orally absorbed, it is unlikely to adversely affect the breastfed infant. Polyethylene glycol is not excreted into breastmilk.
Quoted from Pegvisomant — Drugs and Lactation Database (LactMed®), National Institute of Child Health and Human Development, revised March 15, 2025.
How much pegvisomant gets into breastmilk
Maternal Levels. A woman was being treated during pregnancy for acromegaly with subcutaneous pegvisomant at a dosage that was progressively escalated from 15 mg to 25 mg daily during the course of pregnancy, and presumably postpartum. At an unreported time postpartum, pegvisomant was not detectable (<50 mcg/L) in breastmilk. The patient's breastmilk growth hormone concentration was 0.6 mcg/L compared to <0.1 mcg/L in 3 breastmilk samples from normal healthy mothers.
Infant Levels. Relevant published information was not found as of the revision date.
What has been seen in breastfed infants
A woman with acromegaly was treated with lanreotide Autogel 120 mg monthly, cabergoline 2 mg weekly and pegvisomant 80 mg weekly. She breastfed (extent not stated) her infant and they were followed for 12 years. Her child had normal growth and development.
Effects on milk supply
Relevant published information was not found as of the revision date.
Frequently asked questions
Can you take pegvisomant while breastfeeding?
Limited data indicate that pegvisomant is poorly excreted into breastmilk. The full record is quoted on this page, and the decision is one to make with the person who prescribed it — LactMed itself states it is not a substitute for professional judgement.
Does pegvisomant pass into breastmilk?
LactMed's measured drug levels for pegvisomant are quoted in full on this page, under "How much gets into breastmilk".
Do I need to pump and dump after taking pegvisomant?
LactMed does not frame its records that way — it reports measured drug levels in milk and what has been observed in breastfed infants, which is what this page quotes. "Pump and dump" advice for a specific drug and dose should come from your clinician or a pharmacist, not from a general rule.
More on pegvisomant
LactMed states that the information it presents is not a substitute for professional judgement, and that you should consult your healthcare provider for breastfeeding advice related to your particular situation. Nothing on this page is medical advice.