Last update Aug. 24, 2022

Polyethylene Glycol (PEG)

Very Low Risk

Safe. Compatible. Minimal risk for breastfeeding and infant.

Polyethylene glycol or macrogol is an osmotic laxative that has minimal intestinal absorption. The little that can be absorbed is excreted unmetabolized in the urine. It is made of polymerss whose molecular weight is between 1,000 and 35,000 daltons. The number added to the term "macrogol" defines its molecular weight, eg: macrogol 3350. Oral administration. Another use is pegylation: it is the conjugation of drugs and therapeutic proteins with polyethylene glycol (PEG) to improve their pharmacokinetic profiles and reduce their adverse effects (see Nonacog Beta Pegolpegaspargase, pegfilgrastimpeginterferon alfa, peginterferon beta, Rurioctocog Alfa Pegol)

It is not excreted in breast milk in detectable amount. (Clowse 2017)

Its pharmacokinetic data (almost zero oral bioavailability and high molecular weight) make it impossible to transfer significant quantities into breastmilk.

Its almost null oral bioavailability prevents its transfer to the infant’s plasma via ingested breast milk.

Experts and scientific associations, as well as the manufacturer, consider it compatible with breastfeeding. (LactMed, Gharehbaghi 2016, Briggs 2015, Müller 2013, AEMPS 2010, Mahadevan 2006)


We do not have alternatives for Polyethylene Glycol (PEG) since it is relatively safe.

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

Polyethylene Glycol (PEG) is also known as

Polyethylene Glycol (PEG) in other languages or writings:


Polyethylene Glycol (PEG) belongs to this group or family:


Main tradenames from several countries containing Polyethylene Glycol (PEG) in its composition:


Variable Value Unit
Oral Bioavail. ≈ 0 %
Molecular weight 3.350 - 4.000 daltons
VD 0.69 l/Kg
Tmax 3 hours
4.1 hours


  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. Clowse ME, Förger F, Hwang C, Thorp J, Dolhain RJ, van Tubergen A, Shaughnessy L, Simpson J, Teil M, Toublanc N, Wang M, Hale TW. Minimal to no transfer of certolizumab pegol into breast milk: results from CRADLE, a prospective, postmarketing, multicentre, pharmacokinetic study. Ann Rheum Dis. 2017 Nov;76(11):1890-1896. Abstract Full text (link to original source) Full text (in our servers)
  3. Gharehbaghi K, Gharehbaghi DR, Wierrani F, Sliutz G. [Treatment of Chronic Functional Constipation during Pregnancy and Lactation]. Z Geburtshilfe Neonatol. 2016 Abstract
  4. 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
  5. Müller-Lissner S. [Pharmacological treatment of constipation]. Internist (Berl). 2013 Abstract
  6. Müller-Lissner S. Pharmacokinetic and pharmacodynamic considerations for the current chronic constipation treatments. Expert Opin Drug Metab Toxicol. 2013 Abstract
  7. AEMPS. Macrogol. Ficha técnica. 2010 Full text (in our servers)
  8. Mahadevan U, Kane S. American gastroenterological association institute technical review on the use of gastrointestinal medications in pregnancy. Gastroenterology. 2006 Jul;131(1):283-311. Review. Abstract Full text (link to original source) Full text (in our servers)

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