Key takeaways:
Mucinex D (guaifenesin / pseudoephedrine) and Mucinex DM (guaifenesin / dextromethorphan) are two over-the-counter cough and cold medications. Mucinex D is kept behind the pharmacy counter, while Mucinex DM is kept out on the floor with other cold products.
Mucinex D is better for a stuffy nose and chest congestion. But it’s not recommended for children under age 12 or people with high blood pressure. Mucinex D comes as oral tablets.
Mucinex DM is better for quieting a cough. It’s also safer for people with high blood pressure. Mucinex DM comes in several formulations, including an oral cough syrup.
Mucinex D and Mucinex DM have unique side effects and interactions to consider. Discuss which one may be a better option for you with your pharmacist.
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In the cough and cold aisle of many pharmacies, there are quite a few products to choose from. Mucinex D (guaifenesin / pseudoephedrine) and Mucinex DM (guaifenesin / dextromethorphan) are two of the more popular cough medications available. Their names are very similar, but they contain different ingredients and treat different symptoms of the common cold.
Sometimes, it’s hard to decide which over-the-counter (OTC) cough medication is the right one for you. Below, we’ll go over seven notable differences between Mucinex D and Mucinex DM, so you can choose the best product for your cold symptoms.
1. Mucinex D helps with nasal congestion, while Mucinex DM helps quiet a cough
Mucinex D and Mucinex DM both contain guaifenesin. This expectorant helps relieve chest and nasal congestion by thinning and loosening phlegm (mucus) in your airways, making it easier to swallow or cough up. It may seem like this would make you cough more. But thick, sticky mucus is actually what triggers a wet cough. Thinner mucus is easier for your body to clear on its own, reducing the need to cough.
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Mucinex D and Mucinex DM pair guaifenesin with a different ingredient, however. The “D” in Mucinex D stands for “decongestant” — in this case, pseudoephedrine. The “DM” in Mucinex DM stands for “dextromethorphan,” a cough suppressant.
Pseudoephedrine works by tightening the blood vessels in and around your nasal passages. This eases sinus pressure and congestion. Mucinex D may be a better choice if you have chest congestion and a stuffy nose.
Dextromethorphan works by slowing down your brain’s cough reflex. It helps treat both dry and wet coughs. So Mucinex DM may be a better option if you’re looking for something to help quiet a cough.
Good to know: Mucinex is also sold on its own, without the “D” or “DM” in the name. This form of Mucinex contains only guaifenesin.
2. Mucinex DM is safer if you have high blood pressure
If you have hypertension (high blood pressure), Mucinex DM is a safer choice for cold symptoms than Mucinex D.
The active ingredients in Mucinex DM shouldn’t affect your blood pressure. Mucinex D, on the other hand, can raise your blood pressure because it contains pseudoephedrine. As mentioned, pseudoephedrine tightens blood vessels, which can increase blood pressure.
If you have high blood pressure, talk to your healthcare team before taking Mucinex D. They can recommend a cold medication that can help with your symptoms without affecting your blood pressure. Mucinex DM may be one option.
Cough home remedies: Learn more about home treatments that can help soothe a dry cough and dry up a wet cough.
Dealing with a nagging cough? Sometimes, a cough lingers and won’t go away. Explore causes of and treatments for a persistent cough.
Seeking medical care: Should you see a healthcare professional for that cough? Knowing when to seek treatment can help you avoid more serious health issues.
3. Mucinex DM offers more dosage forms
Mucinex DM is available in more dosage forms than Mucinex D.
Mucinex DM comes as an oral tablet and a cough syrup. If you have trouble swallowing pills, the cough syrup may be a good option. Mucinex Cough & Chest Congestion liquid-filled capsules are another available dosage form. This product contains the same ingredients as Mucinex DM but doesn’t say “Mucinex DM” on the package.
Mucinex D comes only as an oral tablet. This could be a problem if you have trouble swallowing pills.
- Mucinex DGuaifenesin/Pseudoephedrine
- Mucinex DM
- Guaifenesin DMGuaifenesin and Dextromethorphan
4. Mucinex D isn’t recommended for children under age 12
Mucinex D’s OTC label provides dosage information only for adults and adolescents ages 12 and older. This is because Mucinex D contains doses of guaifenesin and pseudoephedrine that are higher than what’s considered safe for kids younger than age 12.
Products that say “Mucinex DM” on the package also aren’t safe for children under 12. But the Mucinex brand offers kid-friendly options that are similar to Mucinex DM. Of note, Mucinex Children’s Cough Mini-Melts are approved for children as young as age 4. Like Mucinex DM, this product contains guaifenesin and dextromethorphan.
5. Mucinex D is kept behind the pharmacy counter
Even though Mucinex DM and Mucinex D are both available without a prescription, Mucinex D is kept behind the pharmacy counter. This is because pseudoephedrine carries a risk of misuse and can be used in the production of illegal methamphetamine.
To help prevent misuse, products containing pseudoephedrine are kept behind the pharmacy counter. There are restrictions limiting how much you can buy per day and per month. You’re also required to present a state or federal photo ID, such as a driver’s license or passport, when purchasing them.
Some states may have additional requirements for or limitations on buying products that contain pseudoephedrine. Your pharmacist can explain the laws for your area in more detail.
Good to know: Mucinex offers another product for nasal congestion, called Mucinex Sinus-Max, that isn’t kept behind the pharmacy counter. It contains acetaminophen (a pain reliever), guaifenesin, and phenylephrine (a decongestant). But phenylephrine isn’t considered an effective decongestant, so this product won’t work as well as Mucinex D.
6. Mucinex D and Mucinex DM may cause different side effects
Because Mucinex D and Mucinex DM both contain guaifenesin, they share some side effects. But they also have unique side effects due to differences in their active ingredients.
| Mucinex D side effects | Mucinex DM side effects |
|---|---|
|
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Both medications have a risk of misuse. Mucinex D is more strictly regulated than Mucinex DM. But Mucinex DM also carries a risk of misuse and overdose. Teens are particularly vulnerable to these effects.
Be sure to follow the recommended dosages for Mucinex D and Mucinex DM. And only take them for up to 7 days in a row unless a healthcare professional tells you otherwise. This helps lower the risk for serious side effects from these cold medications.
7. Mucinex D and Mucinex DM have different drug interactions
Mucinex D and Mucinex DM also interact with different medications. Of note, the guaifenesin component in each product has no known drug interactions.
The pseudoephedrine in Mucinex D interacts with:
Monoamine oxidase inhibitors (MAOIs), such as selegiline (Zelapar, Emsam)
Linezolid (Zyvox)
Tricyclic antidepressants, such as amitriptyline
Ergot migraine medications, such as dihydroergotamine (Migranal, Trudhesa)
Phentermine (Adipex-P, Lomaira)
Phenylephrine
Digoxin (Lanoxin)
Blood pressure medications
The dextromethorphan in Mucinex DM interacts with:
Alcohol
MAOIs
Many antidepressants
Other cough suppressants
These aren’t complete lists of all possible interactions for Mucinex D and Mucinex DM. Be sure to share a medication list with your pharmacist before taking either cold medication. They can make sure Mucinex D or Mucinex DM is safe for you to take with your other medications.
Frequently asked questions
Yes, the pseudoephedrine in Mucinex D may keep you awake if you take it too close to bedtime. A common side effect of decongestants is trouble sleeping.
If Mucinex D disrupts your sleep, try taking it only in the morning. If you need nighttime relief from symptoms, use a product that doesn’t contain pseudoephedrine or another decongestant.
Yes, you can take Claritin-D (loratadine / pseudoephedrine) and standalone Mucinex together, since guaifenesin has no known interactions. Mucinex DM is also safe to combine with Claritin-D.
Read the OTC label carefully to make sure you’re not taking Mucinex D with Claritin-D. The “D” in these products’ names stands for the decongestant pseudoephedrine. Taking multiple “D” cold medications increases the risk of side effects, such as raised blood pressure and a high heart rate.
You can buy Mucinex D at most retail locations that have a pharmacy. This may include certain grocery stores and big box stores. Mucinex D is a behind-the-counter medication. To purchase it, you’ll have to show the pharmacy team a federal or state ID, such as a driver’s license or passport. Each state has its own age and quantity restrictions on Mucinex D and other products that contain pseudoephedrine. Ask your pharmacist for more information on pseudoephedrine restrictions in your area.
Yes, the pseudoephedrine in Mucinex D may keep you awake if you take it too close to bedtime. A common side effect of decongestants is trouble sleeping.
If Mucinex D disrupts your sleep, try taking it only in the morning. If you need nighttime relief from symptoms, use a product that doesn’t contain pseudoephedrine or another decongestant.
Yes, you can take Claritin-D (loratadine / pseudoephedrine) and standalone Mucinex together, since guaifenesin has no known interactions. Mucinex DM is also safe to combine with Claritin-D.
Read the OTC label carefully to make sure you’re not taking Mucinex D with Claritin-D. The “D” in these products’ names stands for the decongestant pseudoephedrine. Taking multiple “D” cold medications increases the risk of side effects, such as raised blood pressure and a high heart rate.
You can buy Mucinex D at most retail locations that have a pharmacy. This may include certain grocery stores and big box stores. Mucinex D is a behind-the-counter medication. To purchase it, you’ll have to show the pharmacy team a federal or state ID, such as a driver’s license or passport. Each state has its own age and quantity restrictions on Mucinex D and other products that contain pseudoephedrine. Ask your pharmacist for more information on pseudoephedrine restrictions in your area.
The bottom line
Mucinex D (guaifenesin / pseudoephedrine) and Mucinex DM (guaifenesin / dextromethorphan) are two popular over-the-counter cough and cold medications. Both can help with chest congestion. Mucinex D also relieves nasal congestion, while Mucinex DM can help quiet a cough.
Each medication has its own side effects and interactions to consider. Mucinex DM is safer if you have high blood pressure, for example. It also comes in more dosage forms than Mucinex D.
You don’t need a prescription to purchase either one. But Mucinex D is kept behind the pharmacy counter, while Mucinex DM is out on the shelf with other cough and cold products.
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References
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RB Health (US). (2023). Mucinex Sinus-Max Severe Congestion Relief - acetaminophen, guaifenesin, and phenylephrine hydrochloride tablet, coated [package insert]. DailyMed.
RB Health (US). (2024). Mucinex Childrens Cough and Chest Congestion Mini-Melts Orange Creme - dextromethorphan hydrobromide and guaifenesin granule [package insert]. DailyMed.
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RB Health (US). (2025). Mucinex D - guaifenesin and pseudoephedrine hydrochloride tablet, extended release [package insert]. DailyMed.
RB Health (US). (2025). Mucinex DM - guaifenesin and dextromethorphan hydrobromide tablet, extended release [package insert]. DailyMed.
RB Health (US). (2025). Mucinex Fast-Max DM Max - dextromethorphan hydrobromide and guaifenesin solution [package insert]. DailyMed.
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