Being a breastfeeding mom with a cold or sinus infection is no joke! 

Not only do you feel miserable, but on top of that you have a baby to take care of. You might be looking for a medication (like Dayquil) to help you feel better throughout the day.

But here’s the problem…

Some drugs can affect breastfeeding, either by hurting milk supply or by passing to your baby through your breast milk. So you need to be very careful of what medications you choose.

Before you reach for Dayquil, you need to get the lowdown!

A fellow mom, Samantha Radford, has her PhD in Chemistry and is going to explain if Dayquil is safe to take during breastfeeding and if it might negatively impact your milk supply.

(this post may contain affiliate links)

What drugs are in Dayquil?

Dayquil is a mixture of 3 medications: Acetaminophen (paracetamol), Dextromethorphan, and Phenylephrine.

• Acetaminophen is the same drug as the active ingredient in Tylenol. It’s meant to help with fever, headache, and other aches from being sick.

• Dextromethorphan is a cough suppressant.

• Phenylephrine is a decongestant.

• Guaifenesin (only in Dayquil Severe Cold and Flu) is an expectorant and loosens phlegm and helps you cough crud up.

Should I stop breastfeeding if I took Dayquil?

If you took Dayquil and then realized after the fact that you’re breastfeeding, it’s okay. You can keep nursing like normal. No need to “pump and dump” or offer formula.

If anything, your baby might briefly be a little cranky due to the Phenylephrine in Dayquil. But don’t worry… Phenylephrine isn’t well absorbed and is not likely to affect your baby.

Should I Stop Breastfeeding If I Have A Cold Or Flu?

No way! There’s absolutely no reason to stop. In fact, your body is producing antibodies to those germs (which you likely already passed to your baby), and those antibodies get passed through breast milk to help protect your baby! It’s best for you both if you keep breastfeeding through an illness.

What are the effects of Dayquil while breastfeeding?

Each medication in Dayquil has a different purpose, and each has a different effect on breast milk and supply. Let’s examine them individually.

Dextromethorphan while breastfeeding

Dextromethorphan is a cough suppressant and is the drug found in Robitussin.  The effects of dextromethorphan on breastfeeding infants and on milk supply hasn’t been specifically studied, but it generally seems to be safe for nursing moms to take.

PRO-TIP: USE HONEY, INSTEAD

Honey is a natural alternative to dextromethorphan that works just as well!

Our favorite honey for when you have a cough is this one. It’s unprocessed and raw for maximum health benefits.

Paracetamol during breastfeeding

Paracetamol (aka Acetaminophen or Tylenol) is safe for breastfeeding.

In fact, it’s often given as a pain reliever directly after birth, when a mom is first establishing her milk supply and the baby is teeny tiny.

The one thing to keep in mind: Many cocktail drugs, not just Dayquil, contain acetaminophen. The big problem here is that acetaminophen has a low therapeutic index, meaning that it’s very easy to overdose on it. 

PRO-TIP:
NEVER take both Dayquil and Tylenol at the same time, regardless of whether you’re breastfeeding.

guaifenesin while breastfeeding

Guaifenesin (also the active ingredient in Mucinex) hasn’t been specifically studied for breastfeeding, but there’s no indication that it is unsafe for milk supply or to take during breastfeeding.

However, a study conducted in 2014, found that guaifenesin didn’t help people cough up any more than a placebo.

Why do we feel like Mucinex helps when it really doesn’t? You’re encouraged to drink lots of water when taking guaifenesin. Drinking more water loosens chest mucus, helping you to cough up all that stuff. If you just drank a lot of fluids without this medication, you would probably still loosen up phlegm in your chest.

Phenylephrine while breastfeeding

Phenylephrine, a nasal decongestant, works as a vasoconstrictor. Basically, it keeps fluid from your blood vessels from flowing out into surrounding tissues. 

This works to reduce nasal decongestion (which is not always from mucus in your nasal passages, but actually from the passages closing up due to swelling). 

As you can imagine, prevention of fluid from blood to surrounding tissue may affect milk production. 

For this reason, phenylephrine is the most concerning drug in Dayquil for breastfeeding mothers. 

Officially, it is considered probably safe for breastfeeding. However, a closely related compound, pseudoephedrine, is known to lower milk supply (it reduced supply by nearly a quarter for moms in the study). In fact, some sources say phenylephrine may reduce milk supply.

In addition, pseudoephedrine has been shown to cause irritability in infants when passed through breast milk. 

When you’re sick, the last thing you want is a cranky baby (who probably won’t sleep).

Bottom Line About Taking Dayquil While Breastfeeding…

A nursing mom could get away with taking Dayquil a time or two, but much more than that could put her supply at risk.

ALTERNATIVES TO DAYQUIL

Safe Cold Medicines While Breastfeeding

Instead, a mix of natural remedies plus some single-medication OTC drugs might work better. Here’s what I suggest:

If you have a headache/fever relief while breastfeeding

• Just take some Tylenol or Motrin. You’ll get to pick exactly the drug you need without anything extra. 

If you have a cough while breastfeeding

Research has shown that dextromethorphan isn’t particularly effective at cough suppression. 

MAKE HONEY TEA

If you want to cut mucus — mix hot water + honey + lemon into a tea. The steam will help clear nasal passages, and the hot honey/lemon mixture will break up mucus so you can cough it up.

Our favorite honey for when you have a cough is this one. It’s raw and darker in color for maximum health benefits. 

Nasal congestion while nursing

Nasal congestion is likely the hardest symptom to deal with when you’re breastfeeding. It’s so frustrating to not be able to breathe well but many medications can threaten milk supply.

• Take a steamy shower. A steamy shower can help break up mucus.

• Take a nasal spray. If your congestion is so bad that you need something stronger, a nasal spray might be helpful. You can try Afrin or Sinex for relief. Just make sure you don’t take it more than 3 days in a row to avoid rebound congestion.

Where can I find more information on which medications are safe for breastfeeding?

When you’re breastfeeding, many doctors will just assume “better safe than sorry” and tell you not to take most drugs. They may even suggest that you have to wean to take a medication. This is almost always not true!

Unfortunately, doctors (including pediatricians and OB/gyns) are often not well trained in lactation science - it’s simply not part of what they’re taught. Therefore, you should check with another resource to find out what medications are safe while breastfeeding.

The National Institutes of Health put out a fantastic (free) app called LactMed. It’s a database of drugs, from antihistamines to antidepressants, and their effects on infants and milk supply.

Conclusions on taking Dayquil while breastfeeding

Bottom line: If you took Dayquil and then panicked after that fact because you remembered that you’re nursing, don’t worry. Everything will be fine!

And we discussed several lower-risk remedies above that should help.

PRO-TIP:  My personal favorite is to heat up homemade chicken stock (here’s an easy recipe that you can then freeze for later) with a crushed garlic clove, chunk of ginger, a little turmeric, and peppercorns. Each of these ingredients are great for the immune system, and they make the broth much tastier too. Sometimes I add a splash of apple cider vinegar to cut congestion. I sip on this broth throughout the day, and it makes me feel much better (especially if I’m dealing with the flu and have nausea as well as respiratory symptoms).

And don’t forget: Rest is the MOST important remedy for a cold or flu. Take care of yourself and cuddle up with the baby. You’ll be on the mend soon!  

Samantha Radford earned her PhD in Chemistry with a focus in Public Health in 2012. She worked from 2012-2020 in higher education. In 2018, she began writing Evidence-based Mommy, where she combines science and wellness to help parents and their children thrive.

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