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Drugs and Lactation Database (LactMed) [Internet]. Bethesda (MD): National Library of Medicine (US); 2006-.

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Drugs and Lactation Database (LactMed) [Internet].

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Last Revision: September 21, 2020.

Estimated reading time: 1 minute

CASRN: 103577-45-3

image 135017944 in the ncbi pubchem database

Drug Levels and Effects

Summary of Use during Lactation

No information is available on the use of lansoprazole during breastfeeding. However, lansoprazole has been used safely in newborn infants, so it is unlikely that the amount in breastmilk would be harmful.

Drug Levels

Maternal Levels. Relevant published information was not found as of the revision date.

Infant Levels. Relevant published information was not found as of the revision date.

Effects in Breastfed Infants

Relevant published information was not found as of the revision date.

Effects on Lactation and Breastmilk

The Spanish pharmacovigilance system found 3 cases of gynecomastia associated with lansoprazole reported during the time period of 1982 to 2006.[1] A retrospective claims database study in the United States found that users of proton pump inhibitors had an increased risk of gynecomastia.[2]

One case of elevated serum prolactin and galactorrhea was reported in a 21-year-old man. When omeprazole was substituted for lansoprazole, the serum prolactin decreased to the normal range and galactorrhea ceased. Although this case occurred in Spain, it was not included in the report above.[3]

A 13-year-old girl with a recent history of bilateral galactorrhea and hyperprolactinemia from omeprazole and domperidone on separate occasions was given lansoprazole to prevent gastrointestinal irritation following intravenous diclofenac for a severe headache. After 3 days of lansoprazole therapy, she again developed galactorrhea and an elevated serum prolactin that returned to normal a week after discontinuing lansoprazole.[4]

A 17-year-old woman using a progestin-containing IUD for 1 year began lansoprazole 15 mg daily and presented after 1 week with bilateral galactorrhea and hyperprolactinemia of 92 mcg/L. Seventy-two hours after discontinuation of lansoprazole, galactorrhea ceased. Four months later, serum prolactin was normal at 24.1 mcg/L with no recurrence of galactorrhea. The authors judged the adverse reaction likely to be caused by lansoprazole.[5]

The prolactin level in a mother with established lactation may not affect her ability to breastfeed.


Carvajal A, Macias D, Gutierrez A, et al. Gynaecomastia associated with proton pump inhibitors: A case series from the Spanish Pharmacovigilance System. Drug Saf. 2007;30:527–31. [PubMed: 17536878]
He B, Carleton B, Etminan M. Risk of gynecomastia with users of proton pump inhibitors. Pharmacotherapy. 2019;39:614–8. [PubMed: 30865318]
Izquierdo Prieto OM, Moreno Alia E, Rosillo González A. Aten Primaria. 2004;34:325–6. [Galactorrhea induced by lansoprazole] [PMC free article: PMC7668912] [PubMed: 15491529]
Jabbar A, Khan R, Farrukh SN. Hyperprolactinaemia induced by proton pump inhibitor. J Pak Med Assoc. 2010;60:689–90. [PubMed: 20726208]
Duwicquet F, Gras-Champel V, Masmoudi K. Therapie. 2017;72:691–3. [Hyperprolactinemia with galactorrhea induced by lansoprazole: A case report] [PubMed: 29061292]

Substance Identification

Substance Name


CAS Registry Number


Drug Class

Breast Feeding


Anti-Ulcer Agents

Gastrointestinal Agents

Proton Pump Inhibitors

Disclaimer: Information presented in this database is not meant as a substitute for professional judgment. You should consult your healthcare provider for breastfeeding advice related to your particular situation. The U.S. government does not warrant or assume any liability or responsibility for the accuracy or completeness of the information on this Site.


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