Mucinex Vs. Mucinex D vs. Mucinex DM:​ What Is The Difference?

In our latest question and answer, the pharmacist discusses the differences between three Mucinex products: Mucinex, Mucinex D and Mucinex DM.


I'm confused about the difference between all the different types of Mucinex products out there. Can you give a rundown on what each product actually has in it?

Asked by Ava On Aug 12, 2021

Answered by
Medical Content Reviewed By HelloPharmacist Staff

On Aug 12, 2021

Key points

  • The primary difference between Mucinex, Mucinex-DM, and Mucinex-D is that they all contain different active ingredients.
  • Mucinex contains a single ingredient, guaifenesin, which is used for chest congestion as it thins and loosens mucus.
  • Mucinex-DM contains two ingredients, the cough suppressant dextromethorphan, and guaifenesin.
  • Mucinex-D contains two ingredients, the nasal decongestant pseudoephedrine, and guaifenesin.

Hello and thank you for your question!

Mucinex is the brand name of several over-the-counter medications used for the treatment of cough and cold symptoms.

There are a variety of different formulations of Mucinex available on the market, including:

  • Mucinex
  • Mucinex-D
  • Mucinex-DM

It can often be difficult to understand the difference between all of these products so, below, I've broken down the ingredients in each, and in what situation you should use them.


Original MucinexFirst and foremost, we have the original product, Mucinex. Mucinex is marketed to help reduce chest congestion, which is essentially the accumulation of mucus in the lungs and upper/lower airways.

Mucinex contains one active ingredient:

  • Guaifenesin

Mucinex also comes in two strengths:

  • Mucinex (containing 600mg of guaifenesin per tablet)
  • Mucinex Extra-Strength (containing 1,200mg of guaifenesin per tablet)

Guaifenesin is classified as an expectorant. It can help to loosen and thin bronchial secretions (i.e. mucus). This is turn, makes it easier for our body to remove these secretions from the airways. It can help turn a dry cough, into a more productive one.

There is conflicting evidence in terms of just how effective guaifenesin is, but it is currently the only over-the-counter FDA-recognized drug that can be legally marketed as an expectorant in the United States.

It is nevertheless considered to be safe and well-tolerated in most individuals, so if you are experiencing symptoms caused by excess mucus, and you're unable to effectively clear it, the original Mucinex is a good option for you.


Mucinex DMNext up, we have Mucinex DM, which contains two active ingredients:

  • Guaifenesin
  • Dextromethorphan

Mucinex-DM also comes in two strengths:

  • Mucinex (containing 600mg of guaifenesin per tablet)
  • Mucinex Extra-Strength (containing 1,200mg of guaifenesin per tablet

The 'DM' in 'Mucinex-DM' stands for dextromethorphan.

Unlike the original Mucinex, Mucinex DM contains two active ingredients. Guaifenesin, as mentioned above, helps to thin and loosen mucus. Dextromethorphan is a very commonly used cough suppressant and is also the active ingredient in Delsym, a popular brand of cough syrup.

Now, it may seem counter-intuitive to use a cough suppressant like dextromethorphan, along with guaifenesin, since coughing can be very helpful in clearing mucus from your chest and throat, especially if the guaifenesin is doing its job and thinning it out.

Well, dextromethorphan, in the vast majority of people, will not completely eliminate your cough, so you will still be able to 'expectorate' and clear out mucus. It will, however, certainly reduce cough frequency, which can help immensely when your throat is irritated and is causing pain. You can of course, still manually try to cough to clear secretions as well.

Mucinex-DM is a good product to choose if you have a nagging, or bothersome cough, along with chest congestion.


Mucinex-DLastly, we have Mucinex-D, which is kept behind the pharmacy counter in the United States.

Mucinex-D contains two active ingredients:

  • Guaifenesin
  • Pseudoephedrine

Guaifenesin is the familiar medication here, used to thin out mucus, and pseudoephedrine is added to this product and used as a nasal decongestant.

Pseudoephedrine is very effective in reducing nasal inflammation, a stuffy nose, and helps clear the sinuses. It is particularly effective when being used to alleviate sinus pressure.

As mentioned, Mucinex-D is kept behind the pharmacy won't find it next to the other Mucinex products stored on the shelf.

This is because of the addition of pseudoephedrine and the law that restricts the sale of such products, the Combat Methamphetamine Epidemic Act.

Mucinex-D is likely the right Mucinex product to choose if you are suffering from nasal congestion/sinus pressure along with chest congestion.

Final Words

So, there you have it, the difference between all of these Mucinex products (Mucinex, Mucinex DM, and Mucinex-D) is simply the active ingredients that each contains.

When folks ask me, or another pharmacist, for an over-the-counter drug recommendation, we generally try to advise you to take drugs to treat only the symptoms you are experiencing.

So, if you are only experiencing chest congestion, original Mucinex would be the way to go, no need to add a cough suppressant like dextromethorphan if you don't have a cough!

Feel free to reach out to us with any more questions in the future!

The Mucinex brand has recently expanded its product offerings with such products as 'Fast-Max' and 'Sinus-Max'.  If you'd like some clarifications or recommendations on these too, we'd be happy to help.


  • Effect of a single 1200 Mg dose of Mucinex® on mucociliary and cough clearance during an acute respiratory tract infection, PubMed
  • Role of guaifenesin in the management of chronic bronchitis and upper respiratory tract infections, PubMed
  • Mucolytics, expectorants, and mucokinetic medications, PubMed
  • Mucinex Manufacturer Website, Mucinex

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!

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