U.S. flag

An official website of the United States government

NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.

Drugs and Lactation Database (LactMed®) [Internet]. Bethesda (MD): National Institute of Child Health and Human Development; 2006-.

Cover of Drugs and Lactation Database (LactMed®)

Drugs and Lactation Database (LactMed®) [Internet].

Show details


Last Revision: February 23, 2021.

Estimated reading time: 2 minutes

CASRN: 60-54-8

image 134970545 in the ncbi pubchem database

Drug Levels and Effects

Summary of Use during Lactation

A number of reviews have stated that tetracycline is contraindicated during breastfeeding because of possible staining of infants' dental enamel or bone deposition of tetracyclines. However, a close examination of available literature indicates that there is not likely to be harm in short-term use of tetracycline during lactation because milk levels are low and absorption by the infant is inhibited by the calcium in breastmilk. Short-term use of tetracycline is acceptable in nursing mothers. As a theoretical precaution, avoid prolonged or repeat courses during nursing. Monitor the infant for rash and for possible effects on the gastrointestinal flora, such as diarrhea or candidiasis (thrush, diaper rash).

Drug Levels

Maternal Levels. In a study using a microbiologic assay, milk tetracycline levels were in an unspecified number of nursing mothers at 9 am after various dosages of tetracycline during the previous days. Whether they had mastitis and the time postpartum were not stated. Milk levels increased to 2.5 mg/L after a daily dose of 1 gram orally for 3 days. Milk levels increased to 2 mg/L after a daily dose of 1.5 grams orally for 2 days. Milk levels increased to 2.5 mg/L after a daily dose of 2 grams orally for 3 days.[1]

Five women were given oral tetracycline 500 mg 4 times a day for 3 days. Milk levels ranged from 0.43 to 2.58 mg/L (times not specified).[2]

After a single dose of 150 mg of tetracycline orally in 2 women, milk levels of tetracycline averaged 0.7 mg at 2 and 6 hours after the dose and had an average peak of 0.8 mg/L 4 hours after the dose.[3]

Infant Levels. Five women were given oral tetracycline 500 mg 4 times a day for 3 days. Their infants were allowed to nurse and tetracycline was undetectable (<50 mcg/L) in the infants' serum.[2]

Effects in Breastfed Infants

No adverse effects were noted in an unspecified number of breastfed infants whose mothers were taking oral tetracycline 1, 1.5 or 2 grams daily for 3 days. Ages of the infants and extent of breastfeeding were not stated.[1] In one study, 5 infants breastfed during maternal therapy with tetracycline 500 mg 4 times daily with no adverse effects observed.[2]

In an observational study of 251 women, 23.8% of nursing mothers received tetracycline during breastfeeding. No gross adverse effect occurred in any of the breastfed infants.[4]

Effects on Lactation and Breastmilk

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

Alternate Drugs to Consider



Grüner JM. Geburtshilfe Frauenheilkd. 1955;15:354–60. [The excretion of terramycin and tetracycline in human milk] [PubMed: 14380696]
Posner AC, Prigot A, Konicoff NG. Further observations on the use of tetracycline hydrochloride in prophylaxis and treatment of obstetric infections. Antibiot Annu. 1954:594–8.
Matsuda S. Transfer of antibiotics into maternal milk. Biol Res Pregnancy Perinatol. 1984;5:57–60. [PubMed: 6743732]
Prakash O, Mathur GP, Kushwaha KP, et al. Drug exposure in pregnant and lactating mothers in periurban areas. Indian Pediatr. 1990;27:1301–2. [PubMed: 2093678]

Substance Identification

Substance Name


CAS Registry Number


Drug Class

Breast Feeding


Anti-Infective Agents

Antibacterial Agents


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.

Copyright Notice

Attribution Statement: LactMed is a registered trademark of the U.S. Department of Health and Human Services.

Bookshelf ID: NBK501108PMID: 30000167


Related information

Similar articles in PubMed

  • Review Demeclocycline.[Drugs and Lactation Database (...]
    Review Demeclocycline.
    . Drugs and Lactation Database (LactMed®). 2006
  • Review Minocycline.[Drugs and Lactation Database (...]
    Review Minocycline.
    . Drugs and Lactation Database (LactMed®). 2006
  • Review Oxytetracycline.[Drugs and Lactation Database (...]
    Review Oxytetracycline.
    . Drugs and Lactation Database (LactMed®). 2006
  • Review Doxycycline.[Drugs and Lactation Database (...]
    Review Doxycycline.
    . Drugs and Lactation Database (LactMed®). 2006
  • Review Tigecycline.[Drugs and Lactation Database (...]
    Review Tigecycline.
    . Drugs and Lactation Database (LactMed®). 2006
See reviews...See all...

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...