Skip to main content
Submitted by admin on 3 January 2019

This recently published study from my laboratories shows that levels of Mesalamine (5-Aminosalicylic acid) in human milk are exceedingly low. Despite the dose,  the relative infant doses in these 10 moms  (RID) were all lower than 0.1%.  Good news,  moms can safely use these products for ulcerative colitis and Crohn's disease.

- Dr. Thomas Hale

Breastfeed Med. 2019 Mar;14(2):98-101. doi: 10.1089/bfm.2018.0111. Epub 2018 Nov 15.

Determination of Mesalamine levels in Human Milk as a Function of Dose.


Oral mesalamine (5-amino salicylic acid [5-ASA]) is an anti-inflammatory agent commonly used to treat inflammatory bowel disease such as ulcerative colitis and Crohn's disease. The transfer of mesalamine into human milk has to date been poorly described at the current dosages and newer formulations. This study was designed to determine transfer of mesalamine into human milk as a function of maternal dose and time, and dosage form.


Ten breastfeeding mothers (age 28-41 years) suffering from inflammatory bowel disease were recruited who provided milk samples at 0, 1, 2, 4, 8, 12, and 24 hours after a single daily dose of oral mesalamine in pH-dependent gastroresistant coated tablets (1.2, 2.4, 3.6, and 4.8 g). Milk samples were analyzed using liquid chromatography/tandem mass spectrometry.


A total of 10 women were enrolled for the study. The calibration curve for mesalamine was linear over a concentration range of 0.32-200 ng/mL. Irrespective of maternal dose, mesalamine levels in milk were exceedingly low. However, a wide range of mesalamine levels were observed among all the participants. The relative infant doses were all lower than 0.1% (range 0.003-0.085%).


Regardless of dose and high variability, mesalamine levels in human milk were present in exceedingly low levels. The mothers in this study reported no side effects with their infants. These results suggest that the transfer of mesalamine into milk is very low and poses minimal risks to the breastfed infant.


5-ASA; human milk; inflammatory bowel disease; mesalamine

PMID: 30431332

DOI: 10.1089/bfm.2018.0111