Is Minoxidil safe while breastfeeding?
Here is what NIH LactMed, the U.S. National Library of Medicine's authority on medicines and breastfeeding, reports about Minoxidil. This is a summary of that source — not our own verdict.
Effects on the breastfed infant
No hypertrichosis or other abnormal signs were seen in one infant breastfed (extent not stated) for 2 months of maternal minoxidil 5 mg twice daily by mouth. The mother was taking the drug throughout pregnancy and postpartum and the infant was born at 37 weeks of gestation.[ 2 ] Another breastfed (extent not stated) infant who was born 4 weeks preterm developed facial hypertrichosis while her mother was using 5% minoxidil topically twice a day. The infant appeared normal at 2 weeks of age, but had considerable black hair on the forehead at 2 months of age. The mother discontinued minoxidil and at 6 months of age, the infant had lost the excess hair. The time course of minoxidil use and hair growth was not clearly specified in the report.[ 3 ] The reaction was possibly caused by minoxidil in milk, but no documentation of maternal or infant serum levels or milk levels was made and normal transient neonatal hypertrichosis is the possible cause. A retrospective study of cases reported to the WHO adverse reaction database, VigiBase, found a total of 45 reports of hypertrichosis in infants attributed to minoxidil. In addition, 11 cases of infantile hypertrichosis or werewolf syndrome were reported in Spain, characterized by excessive, fur-like growth of body hair. It is thought that widespread use of topical minoxidil in these countries was responsible. It was suspected that the drug was inadvertently absorbed via skin-to-skin contact or accidentally ingested by the infants through breastmilk or other unknown sources.[ 4 ]
Effects on milk supply
Relevant published information was not found as of the revision date.
Levels in milk
Maternal Levels. In one case report, a 2-month-postpartum mother who was taking minoxidil 5 mg twice daily was given an oral dose of 7.5 mg. The peak milk level of minoxidil plus glucuronide conjugate was 45.1 mcg/L one hour after the dose. Milk levels paralleled serum levels, falling rapidly after the first hour to a concentration of 12.4 mcg/L at 3 hours, 4 mcg/L at 6 hours, 1.9 mcg/L at 9 hours, 0.8 mcg/L at 12 hours after the dose.[ 2 ] Infant Levels. Relevant published information was not found as of the revision date.
Alternatives LactMed lists
Source: NIH LactMed (National Library of Medicine).
Educational summary of an authoritative source — not medical advice. Never start, stop, or change a medicine while breastfeeding without confirming with your doctor.