Can You Take Mucinex And DayQuil Together?

In our latest question and answer, the pharmacist discusses whether or not Mucinex (guaifenesin) can be taken with DayQuil.


Can you take Mucinex and Dayquil together?

Asked by Ashley On Apr 18, 2022

Answered by
Medical Content Reviewed By HelloPharmacist Staff

Published Apr 18, 2022
Last updated Apr 21, 2022

Key points

  • Mucinex (guaifenesin) is safe to take with DayQuil Cold & Flu. There is no interaction between them.
  • Some DayQuil products already contain guaifenesin, such as DayQuil Severe. Mucinex should not be taken with products that already contain guaifenesin.

Mucinex can safely be taken with the original DayQuil Cold & Flu as there is no interaction between the medications.

However, It is important to be aware that DayQuil is a brand name, and comes in a variety of additional brand formulations (e.g. DayQuil Severe), some of which contain the active ingredient in Mucinex (guaifenesin). It is not recommended to take Mucinex with any DayQuil product that already contains guaifenesin.

It is important to carefully review each product's ingredients to avoid taking too much of the same drug.

Which DayQuil Products Contain Mucinex (Guaifenesin)?

As stated, some DayQuil products already contain the active ingredient guaifenesin (which is the active ingredient in Mucinex). 

See below for a breakdown of the ingredients in some of the more common Dayquil products.

Dayquil Cold & Flu

  • Acetaminophen (analgesic)
  • Dextromethorphan (cough suppressant)
  • Phenylephrine (nasal decongestant)

Dayquil Severe Cold & Flu

  • Acetaminophen (analgesic)
  • Dextromethorphan (cough suppressant)
  • Phenylephrine (nasal decongestant)
  • Guaifenesin (expectorant)

Dayquil Cough DM + Congestion

  • Dextromethorphan (cough suppressant)
  • Phenylephrine (nasal decongestant)
  • Guaifenesin (expectorant)

DayQuil HBP Cold & Flu

  • Acetaminophen
  • Dextromethorphan


To reiterate, it is safe to take Mucinex (guaifenesin) with the original DayQuil (Cold & Flu) formula as that product does not contain guaifenesin.

However, Mucinex should not be used with any DayQuil product that contains guaifenesin already (such as DayQuil Cold & Flu Severe).

Be sure to carefully read the product packaging to avoid taking duplicate or unnecessary medications. Try and match your symptoms to the particular ingredients that you need when possible!


About the Pharmacist

Dr. Brian Staiger, PharmD

Dr. Brian has been practicing pharmacy for over 11 years and has wide-ranging experiences in many different areas of the profession. From retail, clinical and administrative responsibilities, he's your knowledgeable and go-to source for all your pharmacy and medication-related questions! Feel free to send him an email at! You can also connect with Dr. Brian Staiger on LinkedIn.

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