Head-to-head comparisons of medication uses, side effects, warnings, and more.
Key takeaways
Doxylamine (Unisom SleepTabs) and guaifenesin/dextromethorphan (Mucinex DM) are both over-the-counter medications, but they are used for different reasons. Doxylamine is an antihistamine used primarily as a sleep aid to treat insomnia, while Mucinex DM is a combination of an expectorant and a cough suppressant used to relieve cough and chest congestion. Doxylamine is taken once daily before bedtime, whereas Mucinex DM can be taken every 4 to 12 hours depending on the formulation. Doxylamine is available as a tablet, while Mucinex DM comes in tablets, liquids, and dissolvable granules. Common side effects of doxylamine include next-day sleepiness and dizziness, while Mucinex DM may cause stomach upset and drowsiness. You should avoid alcohol with both medications, but Mucinex DM also has interactions with certain depression and Parkinson's medications.
Doxylamine (Unisom SleepTabs)
Mucinex dm (guaifenesin / dextromethorphan)
Doxylamine (Unisom SleepTabs)
Mucinex dm (guaifenesin / dextromethorphan)
Summary of Unisom vs. Mucinex DM
Summary for Antihistamine
Doxylamine succinate (Unisom SleepTabs) is an over-the-counter antihistamine that can be taken by adults and children ages 12 years and older who are having trouble falling asleep. It's a sleep aid that works by blocking certain chemicals (histamine) in your body. Doxylamine (Unisom SleepTabs) is taken by mouth once a day, about 30 minutes before bedtime. The most common side effect of this medication is next-day sleepiness.
Summary for Expectorant / Antitussive
Mucinex DM (guaifenesin / dextromethorphan) is an over-the-counter medication that's used to relieve cough and loosen mucus. It has two active ingredients: guaifenesin (an expectorant that clears chest congestion) and dextromethorphan (a cough suppressant that relieves cough). The medication is available as tablets, dissolvable granules, and liquid that are taken by mouth, each with different dosages, directions, and age limits. Extended-release tablets are taken every 12 hours, while the other forms are usually taken every 4 hours. Most people have few to no side effects when used as directed, but it can sometimes cause stomach upset, dizziness, and drowsiness.