Last update May 27, 2021


Very Low Risk

Safe. Compatible. Minimal risk for breastfeeding and infant.

Proton pump inhibitor, reducing gastric acid secretion.
Oral administration once or twice a day.

Its pharmacokinetic data (very high percentage of plasma protein binding and short half-life) explain the negligible passage to milk observed (Marshall 1998).
No problems have been observed in infants of mothers who took omeprazole (Marshall 1998).
Possible adverse reactions are rare and not serious (Dexcel 2021, AEMPS 2017).

Shown to be labile in acid-pH environment must be administered in the form of micro-granules within an enteric-coated capsule (AEMPS 2017). Any small quantity reaching the infant's stomach would be readily inactivated.

Authorized use in children from one year of age. It has been used in newborns

A similar product, pantoprazole, also has negligible excretion in breast milk and did not cause problems in the infant (Plante 2004).

Manufacturers (Dexcel 2021, AEMPS 2017) and expert authors (Rowe 2013, Nava 2006) consider that the risk of affecting the infant is very unlikely.

Omeprazole and other proton pump inhibitors can cause hyperprolactinemia, galactorrhea, and gynecomastia (Prikis 2020, He 2019, Jabbar 2010).

See below the information of this related product:

  • Pantoprazole ( Safe. Compatible. Minimal risk for breastfeeding and infant.)


  • Famotidine ( Safe. Compatible. Minimal risk for breastfeeding and infant.)
  • Nizatidine ( Safe. Compatible. Minimal risk for breastfeeding and infant.)
  • Pantoprazole ( Safe. Compatible. Minimal risk for breastfeeding and infant.)

Suggestions made at e-lactancia are done by APILAM team, and are based on updated scientific publications. It is not intended to replace the relationship you have with your doctor but to compound it.

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

Omeprazole is also known as

Omeprazole in other languages or writings:


Main tradenames from several countries containing Omeprazole in its composition:


Variable Value Unit
Oral Bioavail. 30 - 60 %
Molecular weight 345 daltons
Protein Binding 95 - 97 %
VD 0,3 l/Kg
pKa 9,29 -
Tmax 1 - 2 hours
T1/2 0,5 - 1 hours
Theoretical Dose 0,003 mg/Kg/d
Relative Dose 0,9 %
Ped.Relat.Dose 0,3 %


  1. Dexcel Ph.. Omeprazol Drug Summary 2021 Full text (in our servers)
  2. Prikis M, MacDougall J, Narasimhadevara N. Proton Pump Inhibitor-Induced Galactorrhea in a Kidney Transplant Recipient: A Friend or Foe? Case Rep Transplant. 2020 May 13;2020:8108730. Abstract
  3. He B, Carleton B, Etminan M. Risk of Gynecomastia with Users of Proton Pump Inhibitors. Pharmacotherapy. 2019 May;39(5):614-618. Abstract
  4. AEMPS. Omeprazol Kern Pharma Ficha técnica 2017 Full text (in our servers)
  5. Rowe H, Baker T, Hale TW. Maternal medication, drug use, and breastfeeding. Pediatr Clin North Am. 2013 Feb;60(1):275-94. Abstract
  6. Jabbar A, Khan R, Farrukh SN. Hyperprolactinaemia induced by proton pump inhibitor. J Pak Med Assoc. 2010 Abstract
  7. Esplugues JV, Martí-Cabrera M. [Safety and interactions of proton pump inhibitors: lessons learned in millions of patients]. Gastroenterol Hepatol. 2010 Abstract
  8. Nava-Ocampo AA, Velázquez-Armenta EY, Han JY, Koren G. Use of proton pump inhibitors during pregnancy and breastfeeding. Can Fam Physician. 2006 Abstract Full text (link to original source) Full text (in our servers)
  9. Richter JE. Review article: the management of heartburn in pregnancy. Aliment Pharmacol Ther. 2005 Nov 1;22(9):749-57. Review. Abstract Full text (in our servers)
  10. Plante L, Ferron GM, Unruh M, Mayer PR. Excretion of pantoprazole in human breast. J Reprod Med. 2004 Abstract
  11. Marshall JK, Thompson AB, Armstrong D. Omeprazole for refractory gastroesophageal reflux disease during pregnancy and lactation. Can J Gastroenterol. 1998 Abstract
  12. Cederberg C, Andersson T, Skånberg I. Omeprazole: pharmacokinetics and metabolism in man. Scand J Gastroenterol Suppl. 1989 Abstract

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