Over-the-counterLower-cost generic availableClass: Respiratory

Mucinex Dm 

(dextromethorphan / guaifenesin)

Over-the-counterLower-cost generic availableClass: Respiratory
Back to: Full Site NavigationSkip to: side effects sectionSkip to: What to expect sectionSkip to: Risks and warnings sectionSkip to: Common concerns from users and pharmacists

Breaks up mucus and relieves cough.

Skip Upsides & Downsides section. Skip to side effects section.

Our bottom line

Mucinex Dm (Dextromethorphan / Guaifenesin) is okay for loosening congestion in your chest and throat, but it could prevent you from coughing the mucus up. It comes as an extended-release tablet and a short-acting liquid.

Price and discounts
Prices and coupons for 20 (600mg/30mg) tablets of mucinex-dm
What is GoodRx?


  • Mucinex Dm (Dextromethorphan / Guaifenesin) is a combination medicine that relieves multiple cold symptoms. It's good to use if you have chest congestion and a cough.
  • Helps loosen the mucus and phlegm that builds up in productive and wet coughs.
  • The extended release version of Mucinex DM lasts up to 12 hours.
People say this drug is:
15 reviews


  • Mucinex Dm (Dextromethorphan / Guaifenesin) isn’t useful if you have a dry cough without mucus or phlegm.
  • The two medications in this product could potentially work against each other. Guaifenesin makes mucus easier to cough up, while dextromethorphan (the "DM" in Mucinex Dm (Dextromethorphan / Guaifenesin)) stops you from coughing.
  • Can cause sleepiness, dizziness, and an upset stomach.
How it works

Mucinex Dm (Dextromethorphan / Guaifenesin) is a combination medicine. Guaifenesin is an expectorant that breaks up and thins out mucus. Dextromethorphan is a cough suppressant.

Skip side effects section. Skip to What to Expect and Pharmacists Tips section.

Side effect rates for Mucinex Dm (dextromethorphan / guaifenesin)

0 reports
These are side effects of Mucinex Dm (dextromethorphan / guaifenesin) reported to the FDA by people taking it, and by doctors and pharmacists.
Filter group. All currently selected
Filter group. All currently selected

Risks and Warnings for Mucinex Dm (dextromethorphan / guaifenesin)

Skip risks section. Skip to common concerns section.
  • People taking Mucinex Dm (Dextromethorphan / Guaifenesin) have reported nausea and vomiting. This is very rare and usually not serious. If you develop a fever with the nausea and vomiting, then talk to your doctor right away.

Common concerns from people taking Mucinex Dm (dextromethorphan / guaifenesin)

Final section. Do you want to return to drug navigation?
  • Last winter I had this problem where when I would lay down to sleep I would start coughing. I took this and 20 minutes later I laid down - no coughing. After a week or so the problem went away. Came back again later and this helped again.