Is Peppermint safe while breastfeeding?
Here is what NIH LactMed, the U.S. National Library of Medicine's authority on medicines and breastfeeding, reports about Peppermint. This is a summary of that source — not our own verdict.
Effects on the breastfed infant
Nursing mothers who were participating in an experiment on the excretion of 1,8-cineole in breastmilk took a 100 mg capsule of 1,8-cineole orally. Although instructed not to, 12 mothers breastfed their infants during the experiment. Mothers reported that none of their infants refused their milk or breastfed less than usual. Two mothers felt that their infants were more agitated a few hours after breastfeeding. A third mother reported that the infant stopped nursing from time to time and looked puzzled but resumed nursing. Upon repeating the experiment 6 weeks later, the infant did not react in an unusual way during breastfeeding.[ 18 ]
Effects on milk supply
Peppermint has been used to suppress lactation;[ 11 ] however, no clinical trials have been found that demonstrate lactation suppression. Menthol can suppress milk production in cell culture and in mice.[ 12 ] In humans menthol is rapidly converted to its glucuronide metabolite after oral ingestion.[ 19 ] It is not clear if the glucuronide has any lactation suppressing effect or if typical peppermint intake would be adequate to suppress lactation in humans.
Levels in milk
The flavor of peppermint comes primarily from its menthol content, but 1,8-cineol (eucalyptol) is also present. Maternal Levels . Eighteen lactating women were given 100 mg of l-menthol in a capsule on 3 test days. Milk samples were collected every 2 hours for 8 hours starting at the time of ingestion. Menthol was detected in milk at all collection times, with the average concentrations of 2.1 mcg/L at 0 hours, 4.9 mcg/L at 2 hours, 5.9 mcg/L at 4 hours, 5.8 mcg/L at 6 hours and 4.1 mcg/L at 8 hours after the dose. The average peak menthol concentration in milk was 8 mcg/L. Only small amounts of menthol glucuronide metabolites were present in the milk samples.[ 13 ] Twelve nursing mothers who were 19 weeks to 19 months postpartum ingested 100 mg of 1,8 cineole in the form of delayed-release capsules (Soledum-Klosterfrau Vertriebs GmbH, Germany) that release the drug in the intestine. Then they pumped 1 to 4 milk samples at the time they perceived the smell of eucalyptus on their breath which had been previously shown to be approximately concurrent. A total of 21 milk samples were obtained. Odor was rated by a panel of 3 to 5 experts as either smelling like eucalyptus or not. Fourteen of the samples had a distinct eucalyptus-like odor. Chemical analysis of the positive odor tests found 1,8-cineole in concentrations from 70 to about 2090 mcg/kg of milk, most in the range of 100 to 500 mcg/kg of milk. Samples with negative odor tests contained concentrations in the range of 0.98 to about 20.23 mcg/kg of milk. In one woman who donated 3 samples, the highest concentration of 71 mcg/kg occurred at 1.5 hours after ingestion, with concentrations of 1 mcg/kg before ingestion and 15 mcg/kg at 9.5 hours after ingestion.[ 14 ] Eight women had their milk analyzed for 1,8-cineole metabolites. Ten metabolites and several enantiomers of these metabolites were detected.[ 14 , 15 ] Eighteen nursing mothers who were nursing their infants of 8 to 53 weeks of age were served a curry dis
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.