To evaluate the effectiveness of a topical preparation of peppermint water in comparison with that of expressed breast milk for the prevention of nipple cracks in primiparous breastfeeding women.

One hundred and ninety-six primipara participants, who are breastfeeding after delivery at 38 or more week gestation, were assigned randomly to 2 groups, with one of 2 regimens (peppermint water, an old household remedy, and no treatment only using breast milk) to right and left sides. Each group was followed for a maximum of 3 visits within 14 days and until the 6 weeks postpartum by telephone call. The aerial parts of Mentha piperita were purchased from Hakim Momen Tabrizi Company, and the identity was confirmed by morphological characterization in comparison with the herbarium specimen retained in the School of Pharmacy, Tabriz University of Medical Sciences. Also, a voucher specimen has been generated in that herbarium.

Inclusion Criteria:

• New mothers with healthy term infants (38 weeks gestation or more) are eligible for recruitment into the study. The sample of breastfeeding mothers were collected in two cohorts according delivery type. Each group consisted of 98 primipara mothers.

Exclusion Criteria:

• Mothers who didn't plan to use peppermint water
• Discharged before an interview or had preterm delivery
• Postpartum fever
• Breast infection
• Nipple abnormalities
• Age less than 18 years
• Twins
• Taking medications at night
• Mothers who didn't have telephone line, and who were illiterate.
• Infants who used bottle-feeding or pacifier, or who had mouth infection, or an abnormal short frenulum.