Last update July 22, 2022

Mefenamic Acid


Safe substance and/or breastfeeding is the best option.

It is a low-potency nonsteroidal anti-inflammatory drug (NSAID). It is used for mild to moderate pain (headache, dental, postoperative, postpartum, dysmenorrhea, menorrhagia, osteoarthritis, and rheumatoid arthritis). Oral administration three to four times a day.

Excretion into breast milk is non-significant without side-effects reported in breastfed infants from treated mothers. (Buchanan 1968)

It was not found, or, only in very low levels neither in the plasma nor the urine of those infants. (Buchanan 1968)

Several medical societies and expert authors consider the use of this medication to be safe or very probably safe during breastfeeding (Briggs 2015, Nice 2004, Goldsmith 1989). The American Academy of Pediatrics (2012) rates it as a maternal medication that is usually compatible with breastfeeding. (AAP 2001)

Until more published data is known about this drug in relation to breastfeeding, known safer alternatives are preferable, especially during the neonatal period and in the event of prematurity. (LactMed, Sachs 2013)


  • Ibuprofen (Safe substance and/or breastfeeding is the best option.)
  • Paracetamol (Safe substance and/or breastfeeding is the best option.)

Suggestions made at e-lactancia are done by APILAM team of health professionals, and are based on updated scientific publications. It is not intended to replace the relationship you have with your doctor but to compound it. The pharmaceutical industry contraindicates breastfeeding, mistakenly and without scientific reasons, in most of the drug data sheets.

Jose Maria Paricio, Founder & President of APILAM/e-Lactancia

Your contribution is essential for this service to continue to exist. We need the generosity of people like you who believe in the benefits of breastfeeding.

Thank you for helping to protect and promote breastfeeding.

José María Paricio, founder of e-lactancia.

Other names

Mefenamic Acid in other languages or writings:


Main tradenames from several countries containing Mefenamic Acid in its composition:


Variable Value Unit
Oral Bioavail. 90 %
Molecular weight 241 daltons
Protein Binding > 90 %
VD 1.1 l/Kg
pKa 3.89 -
Tmax 2 - 4 hours
2 - 4 hours
M/P ratio 0.2 -
Theoretical Dose 0.026 (0.005 - 0.1) mg/Kg/d
Relative Dose 0.2 (0.04 - 0.8) %


  1. LactMed. Drugs and Lactation Database (LactMed). Internet. Bethesda (MD): National Library of Medicine (US); 2006-. Available from: 2006 - Consulted on April 16, 2024 Full text (link to original source)
  2. Briggs GG, Freeman RK, Towers CV, Forinash AB. Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk. Wolters Kluwer Health. Tenth edition (acces on line) 2015
  3. PDR. Mefenamic Acid. Drug Summary. 2014 Full text (link to original source) Full text (in our servers)
  4. Sachs HC; Committee On Drugs. The transfer of drugs and therapeutics into human breast milk: an update on selected topics. Pediatrics. 2013 Sep;132(3):e796-809. Abstract Full text (link to original source) Full text (in our servers)
  5. Acido Mefenamico. Ficha técnica. 2009 Full text (in our servers)
  6. Nice FJ, De Eugenio D, Dimino TA, Freeny IC, Rovnack MB, Gromelski JS. Medications and Breast-Feeding: A Guide for Pharmacists, Pharmacy Technicians, and Other Healthcare Professionals. Part I. J Pharm Technol 2004;20:17-27. doi: 10.1177/875512250402000106.
  7. AAP - American Academy of Pediatrics Committee on Drugs. Transfer of drugs and other chemicals into human milk. Pediatrics. 2001 Sep;108(3):776-89. Abstract Full text (link to original source) Full text (in our servers)
  8. Goldsmith DP. Neonatal rheumatic disorders. View of the pediatrician. Rheum Dis Clin North Am. 1989 Abstract
  9. Buchanan RA, Eaton CJ, Koeff ST, Kinkel AW. The breast milk excretion of mefenamic acid. Curr Ther Res Clin Exp. 1968 Abstract

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