Skip to main content

Is Nyquil safe to take while breastfeeding?

Medically reviewed by Carmen Pope, BPharm. Last updated on Feb 25, 2022.

Official answer


It is best not to take Nyquil while breastfeeding because it contains ingredients such as doxylamine that may affect your milk supply, and cause drowsiness in you and your newborn. Liquid formulations of Nyquil also contain alcohol which is not recommended during breastfeeding. However, in general, occasional use of Nyquil at recommended dosages has been used by thousands of breastfeeding women who perceive the benefits outweigh the risks with almost no documented adverse effects being reported in their infants.

There are many different Nyquil preparations so check the product label for a list of the key ingredients contained in yours. Common ingredients in Nyquil preparations may include acetaminophen, dextromethorphan, doxylamine, and sometimes phenylephrine.


Acetaminophen is considered safe to take while you are breastfeeding according to the American Academy of Pediatrics, although it is best to only take it when needed and never exceed the recommended dose. Acetaminophen is excreted into breast milk in very small amounts with peak levels occurring 1 to 2 hours after dosing. Research has shown breastfeeding infants receive an average of 0.14% (range 0.04% to 0.23%) of the mother's dose; which works out to be about 2% of the maximal maternal weight-adjusted dose. These doses work out to be about 0.5% of the lowest recommended infant dose, and because acetaminophen is approved for use in infants, acetaminophen is considered compatible with breastfeeding and has been widely used without apparent harmful effects. There is one documented report of a maculopapular rash occurring in a 2-month old nursing infant whose mother was receiving acetaminophen, which recurred when acetaminophen was given to the mother again.


It is unknown if dextromethorphan is excreted into human milk and there have been no animal studies, but it likely passes into human breastmilk in small amounts. Usual doses are considered unlikely to cause harm to a nursing infant, especially infants older than 2 months. The benefits of using dextromethorphan should outweigh the risks but based on the small amount of information that is available, dextromethorphan is considered safe to use while breastfeeding.


Doxylamine is excreted into human milk and experts recommend it should be avoided during breastfeeding or if planning to breastfeed. However, small occasional doses of doxylamine would not be expected to cause any adverse effects in breastfed infants; but large doses or more prolonged use may cause drowsiness, hyperactivity, or irritability in nursing infants and also decrease the milk supply, because doxylamine is an antihistamine that can dry up secretions which may decrease milk production, especially if used with a decongestant, such as phenylephrine or before lactation is well established.

One survey reported irritability and colicky symptoms in 10% of infants whose mothers received antihistamines and drowsiness in 1.6%. None required medical attention.


It is unknown if phenylephrine is excreted into human milk but animal studies indicate that phenylephrine may decrease milk production. Phenylephrine does likely pass into breastmilk, but it is poorly absorbed orally so the overall effects on a breastfeeding infant would likely be small. The manufacturer makes no recommendation regarding use during lactation.


The liquid forms of Nyquil also contain alcohol as an inactive ingredient. Alcohol can pass through breast milk and cause problems such as irritability or changes in sleep patterns. To help avoid these problems, some experts recommend waiting 2 to 2.5 hours before breastfeeding after having any kind of alcohol, including the small amounts that are in liquid Nyquil.

  • Doxylamine Pregnancy and Breastfeeding Warnings. Updated 01/2022.
  • Dextromethorphan Pregnancy and Breastfeeding Warnings. Updated 04/2021.
  • Acetaminophen Pregnancy and Breastfeeding Warnings Updated 10/2021.
  • Phenylephrine Pregnancy and Breastfeeding Warnings. Updated 05/2021.

Related medical questions

Related support groups