Can You Mix Mucinex With Cough Syrup?

Whether or not you can combine Mucinex with your cough syrup depends on the specific product in question.


I was wondering if it was safe to mix two over-the-counter medications, Mucinex and cough syrup.

Asked by Micky On Nov 17, 2022

Answered by
Medical Content Reviewed By HelloPharmacist Staff

Published Nov 17, 2022
Last updated Nov 17, 2022

Key points

  • Mucinex (guaifenesin) is safe to take with most cough medicines, as long as they don't already contain guaifenesin (it's a commonly used ingredient OTC cough/cold formulas).


Whether or not you can take Mucinex with your cough syrup depends on what the active ingredients in the cough syrup are. 'Cough syrup' is a bit of a generic term, so it is important to figure out what the 'cough syrup' actually contains.

Mucinex (guaifenesin) is actually an active ingredient in many over-the-counter (OTC) cough syrups so the most important consideration is to not take a cough syrup that already contains guaifenesin. Doing so could result in an increased risk of side effects from too high of a dose.

The most common ingredient in cough syrups, aside from guaifenesin, is dextromethorphan. Dextromethorphan is safe to take with guaifenesin. In fact, many cough products contain both, such as Mucinex DM and Robitussin DM.

In terms of actual drug interactions, Mucinex (guaifenesin) is one of the few drugs that isn't known to have any clinically significant ones. So, as long as the 'cough syrup' you are looking at doesn't contain guaifenesin, Mucinex will be safe to take with it.

In the next section, let's look at some popular over-the-counter cough syrups so you can get an idea of their contents.

  • Delsym
  • Robitussin products
  • DayQuil

Over-The-Counter Cough Syrups

The following are several examples of common over-the-counter cough syrups.


Delsym is an extended-release cough syrup that contains dextromethorphan. As stated above, dextromethorphan is safe with guaifenesin. Therefore, Mucinex is safe to take with Delsym.

Robitussin/Robitussin DM

There are over 7 Robitussin products available, such as Robitussin Cough and Chest and Robitussin Multi-Symptom CF.

Since there are so many different types of Robitussin products, it is extremely important to look at the 'Drug Facts' on the packaging. If the Robitussin product contains guaifenesin, it should not be taken with Mucinex.

If the Robitussin product does not contain guaifenesin (such as Robitussin 12-Hour Cough Relief), then Mucinex will be safe to take with it.


Like Robitussin, there are a variety of DayQuil products available, all with different ingredients.

DayQuil (the non-severe formula) is safe to take with Mucinex since it does not contain guaifenesin.

However, DayQuil Severe, which does contain guaifenesin, should not be taken with Mucinex.

What Cough Syrup Is Mucinex Safe To Take With?

There are far too many over-the-counter cough syrups to list here, but you can simply follow the direction that as long as the cough syrup you intend on taking doesn't already contain Mucinex (guaifenesin), you can combine them as Mucinex has few, if any, clinically significant drug interactions.

Mucinex Information

Mucinex With Blister Tabs on table

Mucinex (guaifenesin) is an expectorant for the treatment of chest congestion. It is commonly used to treat coughs due to colds and respiratory infections. It is classified as a mucolytic since it aids in the breakdown of mucus.

Mechanism Of Action

Guaifenesin works by thinning and loosening mucus/bronchial secretions. Specifically, it reduces the viscosity and adhesiveness of these secretions, making them easier to remove and cough out. This can help to change a dry, unproductive cough to one that is more productive.

Side Effects

Adverse reactions to guaifenesin, when given at recommended dosages, are uncommon and generally not serious. Nevertheless, the following side effects have been reported:

  • Nausea
  • Vomiting
  • Diarrhea
  • Drowsiness
  • Dizziness
  • Headache

Excessive use/high doses of guaifenesin have been reported to cause kidney stones, but this is thought to be extremely rare. In case reports, other factors contributed to their formation as well.

Drug Interactions

There are no known drug interactions with guaifenesin.


(Adults) Immediate Release: 200 to 400 mg every 4 to 6 hours as needed

(Adults) Extended-Release: 600 to 1200 mg every 12 hours as needed

(Adults) Maximum Daily Dose: 2400 mg/day

Final Words

I hope you found this information helpful!

As always, reach back out if anything else comes up.


  • Guaifenesin Monograph, PubChem
  • Robitussin Manufacturer Website, Robitussin
  • Guaifenesin- and ephedrine-induced stones, PubMed

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