Medications and Breastfeeding

Most medications are compatible with breastfeeding because usually only a very small proportion actually reaches the breast milk. The amount of medication that reaches a baby through breast milk will depend on a number of the drugs’ properties such as half life1, molecular size, fat solubility, protein binding and what happens to it in the baby’s gut 2. If one drug isn’t recommended there is often an alternative that is safer or more compatible. Many diagnostic tests are compatible with breastfeeding as well.

This article

This article looks at a mother’s options if her doctor asks her to stop breastfeeding in order to take a medication, discusses why stopping breastfeeding isn’t usually needed and provides resources to check drug compatibility with breastfeeding.

My doctor told me to stop breastfeeding

Sometimes a breastfeeding mother may need to take a medicine that her health professional says isn’t compatible with breastfeeding. If your doctor tells you to stop breastfeeding in order to take a specific medication, check whether they have consulted one of the resources specific to breastfeeding and medications below, or whether a more compatible drug could be prescribed. The drug companies package insert may not be a reliable source of information on drug safety when breastfeeding:

Unfortunately, most healthcare professionals simply review the package insert or advise the mother not to breastfeed without having done a thorough study of the literature to find the true answer. Discontinuing breastfeeding is often the wrong decision, and most mothers could easily continue to breastfeed and take the medication without risk to the infant. Even the FDA [US Food and Drug Administration] has recognized this and now recommends that drug manufacturers carry out studies to determine milk levels of their drug.

Explain that breastfeeding is important

Explain to your doctor how important breastfeeding is to you and your baby. As Jack Newman, a Canadian paediatrician and breastfeeding expert, says below, breastfeeding is too important to mother and baby to be stopped unnecessarily:

There are some rare situations in which a mother’s or baby’s illness means that breastfeeding cannot continue. Too often, though, health professionals recommend weaning the baby without thinking. In the vast majority of cases, stopping breastfeeding is detrimental to the baby and the mother and completely unnecessary. A health professional who is truly supportive of breastfeeding will make every effort to find ways for the mother to continue at the same time as helping her to cope with medical conditions.

The National Institute for Health and Care Excellence (NICE) provides national guidance and advice to improve health and social care in UK. They recommend health professionals and pharmacists consult LactMed or the Specialist Pharmacy Service (see below) when prescribing to breastfeeding mothers. They state:

Health professionals should discuss the benefits and risks associated with the prescribed medication and encourage the mother to continue breastfeeding, if reasonable to do so. In most cases, it should be possible to identify a suitable medication which is safe to take during breastfeeding by analysing pharmokinetic and study data. Appendix 5 of the ‘British national formulary’ should only be used as a guide as it does not contain quantitative data on which to base individual decisions.

Stopping breastfeeding is not usually necessary

The Womanly Art of Breastfeeding summarises why stopping breastfeeding is not usually necessary:

  • Even if a mother’s blood level for a given drug is high, it’s still very dilute for her breastfeeding baby to swallow in her milk, digest, and put into his bloodstream.
  • Age matters. Some drugs that might be a concern for premature infants are not a concern for full-term babies. The older the baby, the less the concern. Some mothers are mistakenly told to wean for a drug that may be given directly to babies or small children.
  • When in doubt, check the baby’s blood or just watch for changes like diarrhea or fussiness.
  • Temporary weaning—and pumping, and bottle-feeding an unhappy baby—is a huge physical and emotional stress during an already stressful time.
  • Breastfeeding is not a faucet. Turning it off abruptly can mean turning it off permanently. Talk about risks!
  • Further risk reduction: Nursing before taking the dose, waiting five “ half- lives,” finding a safer drug or treatment, even nursing part-time—all far better choices than even temporary weaning.
  • Drug companies tend to recommend weaning to avoid litigation. The actual research rarely supports weaning.

Checking medications and breastfeeding

Your health professional will need to review the safety of each medication because there are a few drugs that are not compatible with breastfeeding. Reputable resources for checking medications and breastfeeding include:

#1 Hale’s Medications and Mothers’ Milk

  • Book. Clinical pharmacologist, Dr. Thomas Hale is the author of a comprehensive and regularly updated book evaluating the compatibility of medications with breastfeeding: Hale’s Medications & Mothers’ Milk 2021: A Manual of Lactational Pharmacology, 2021.
  • Website. There is also an online version of the book at Hale’s Medications and Mothers’ Milk for health professionals (requires a subscription).
  • App. Available as a mobile app for android or apple devices via Infant Risk Center called MommyMeds.

#2 LactMed (website)

A free Drugs and Lactation Database from the US National Library of Medicine—LactMed online.

#3 E-lactancia (website)

E-lactancia is a free online resource from APILAM 3 in Spain. It includes information on breastfeeding and phytotherapy (plants), homeopathy, cosmetic and medical procedures, contaminants, maternal and infant diseases and more. Information is available in Spanish or English.

#4 UK Drugs in Lactation Advisory Service (UKDILAS)

A service from the UK Medicines Information Network by the Trent and West Midlands Regional Medicines Information Centres. UKDILAS provides evidence based information for medications available in the UK for healthcare professionals and members of the public via

#5 The Breastfeeding Network (Breastfeeding Charity in UK)

#6 Telephone helplines

#7 Drugs and breastfeeding (Swedish)

Läkemedel och amning; a free online drugs and breastfeeding database for health professionals in Swedish by Stockholm County Council.

#8 Books

In addition to Hale’s Medications & Mothers’ Milk 2021: A Manual of Lactational Pharmacology (2021): other helpful books that discuss the safety of individual drugs when breastfeeding include:

medications and breastfeeding

If you do need to stop breastfeeding

If you do need to wean due to medical reasons have a look at How to Stop Breastfeeding so that you can stop breastfeeding without getting engorgement or mastitis.


If your doctor is not supportive of breastfeeding and asks you to stop breastfeeding to take a medication, explain how important breastfeeding is to you and your baby. Most medications are compatible with breastfeeding. If a particular drug is not compatible, alternatives with a better safety record are often available. Share the resources listed above and discuss with your physician whether an alternative treatment is possible.

**Extracts reproduced by permission from Pinter & Martin