Guaifenesin (Mucinex): Uses, Dosage, Side Effects, and Abuses
February 05, 201901,989

Guaifenesin (Mucinex): Uses, Dosage, Side Effects, and Abuses


What is Mucinex?

Mucinex is the common brand name form of the drug guaifenesin. It is an expectorant used to reduce the amount of mucus in your lungs, nose and chest when you have a cold or are suffering from allergies.1 It does this by thinning your mucus, which allows your body to remove it on its own more easily.1

Mucinex is available over the counter. You can buy it without a prescription from your doctor.1

You can buy Mucinex at pharmacies and grocery stores and it often costs less than one dollar per dose.4 You should have no trouble finding Mucinex wherever you shop.2


Types of Mucinex

Mucinex is available combined with many other drugs.2 These combinations make Mucinex more effective or allow you to treat many symptoms of your cold at once.  Mucinex may be combined with:

  • Decongestants

Decongestants cause your body to make less mucus. This makes Mucinex more effective at decreasing symptoms of congestion.2,4

Mucinex combined with the decongestant pseudoephedrine is most common. This mixture is sold under the name Mucinex D.2

Though Mucinex D is not a prescription drug, you do have to buy it from behind the pharmacy counter.2

  • Pain-killers

Pain-killers reduce aches, pains and headaches that may accompany a cold.2

Mucinex is often combined with the pain-killer acetaminophen. This combination is sold under the brand name Mucinex Sinus Max. This drug also contains a decongestant called phenylephrine.2

  • Cough Suppressants

Cough suppressants help stop “dry” coughs.  Dry coughs are caused by a tickle in your throat, not mucus.2 Combining a cough suppressant with Mucinex can be very helpful for relieving the symptoms of a chest cold.

Mucinex is often combined with the cough suppressant dextromorphan.  This mixture is sold under the brand names Mucinex DM and Robitussin.2,5

Mucinex and dextromorphan are also in Mucinex Sinus Max Night Time, along with a decongestant and a sleep aid.2

The most common Mucinex products are listed below (Table 1). Many other combinations of Mucinex exist, however. Which product you should choose depends on what symptoms you have.


Table 1: Most Common Mucinex Products2

MucinexGuaifenesin 600 mg
Mucinex DGuaifenesin 600 mg

Pseudoephedrine HCl 60mg

Mucinex DMGuaifenesin 600 mg

Dextromorphan HBr 30 mg

Mucinex Sinus MaxAcetaminophen 325 mg

Guaifenesin 200 mg

Phenylephrine 5 mg


Mucinex Uses

Colds, Bronchitis & Allergies

Mucinex is an expectorant. It is used to treat symptoms caused by too much mucus in your airways. These symptoms can include1:

  • runny nose
  • stuffy nose
  • sore throat
  • coughing
  • wheezing
  • difficulty breathing


Mucinex works for many conditions that cause too much mucus to build up in your airways. These include1:

  • a chest cold
  • a head cold
  • bronchitis
  • allergies



For a long time, scientists thought Mucinex may be able to treat the symptoms of fibromyalgia as well. Fibromyalgia is a nerve disorder that causes widespread, chronic pain.6

Unfortunately, studies now show that Mucinex is not helpful for those with fibromyalgia.6


Mucinex Dosage

Adult Dosage

The adult dosage of Mucinex is 2400 mg per day. How you take this 2400 mg depends on the type of Mucinex you are taking.1

Pill Forms

If you are taking Mucinex by itself, it is usually in pill form. These pills usually contain 1200 mg of guaifenesin. You should take one pill every 12 hours.1

Liquid Forms

If you are taking Mucinex combined with other drugs, it is often in liquid form.2 The volume of liquid you need to take per dose will be listed on the label. Most Mucinex products come with a small dosage cup to help you make sure you are getting the right amount.1

Most liquid forms of Mucinex contain 400 mg of guaifenesin. This means you can take up to six doses per day, or every 4 hours.1

Though taking up to 1200 mg of Mucinex at one time is safe, you should not take more than a single dose of liquid Mucinex at one time. Nor should you take doses more frequently than once every 4 hours.  This is because doing so could cause you to overdose on the other drugs in the liquid Mucinex product.1,2

Child Dosage

Mucinex is available for children over the age of four in a liquid form.1 Children under the age of four should not use Mucinex.1

The only difference between children’s Mucinex and adult Mucinex is the dosage. Instead of 400 mg of guaifenesin, children’s Mucinex contains 100 mg per dose.1 Children’s Mucinex may be taken every four hours.

Mucinex Side Effects

Common Side Effects

Most people do not have any side effects when taking Mucinex.7

Those who do, however, most commonly experience7:

  • nausea
  • vomiting

If these side effects are too much to tolerate, you should stop using Mucinex, and look into other remedies for your cough or cold.


Serious Side Effects

Allergic Reaction

As with all drugs, Mucinex can cause an allergic reaction. If you develop symptoms of an allergic reaction, such as a skin rash or sudden problems breathing, seek medical help immediately.7

Kidney Stones

Long-term overuse of Mucinex may cause kidney stones.16


Combination Product Side Effects

It is important to keep in mind that the other drugs in the Mucinex combination products can cause side effects as well. What these side effects are depend on what drug(s) are in the product.

For example, the drugs added to Mucinex D and Mucinex DM can cause8,15:

  • fast heart beat
  • problems breathing
  • clumsiness
  • headache
  • dry mouth


You should always ask your doctor or pharmacist if you are unsure about the side effects of any drug.

Warnings for Mucinex Use

General Warnings

Mucinex can cause an allergic reaction. Seek medical help immediately if you experience symptoms of an allergic reaction, such as a rash or shortness of breath.7

Always take Mucinex exactly as it states on the packaging. This is even more important if the Mucinex product also contains other drugs. Overdoses can occur more easily in Mucinex products that contain a decongestant or cough suppressant as well.9

Warnings for Special Groups

Pregnant Women 

Studies have found weak links between Mucinex and birth defects.10 Pregnant women should only take Mucinex if absolutely necessary. If you are pregnant, it is best to speak to your doctor before taking Mucinex.

Nursing Women

Mucinex may pass into the breast milk of nursing women. If you are nursing, you should ask your doctor before taking Mucinex.1

Warnings for Combination Drugs

The other drugs in Mucinex combination products can be dangerous for some groups of people for whom Mucinex itself would be safe. These include11:

  • people with high blood pressure
  • people taking medication for depression

If you have high blood pressure, depression or another serious condition, talk to your doctor or pharmacist before taking one of these combination products.

Mucinex Compared to Other Similar Drugs


Mucinex vs Sudafed

Both Mucinex and Sudafed can be used to treat the symptoms of excess mucus in your airways, but they work differently.

Mucinex contains an expectorant, which thins your mucus. This makes it easier for your body to get rid of it.1

Sudafed contains a decongestant, which causes your body to produce less mucus in the first place.4

Often, these drugs are used together (such as in the product Mucinex D) because their effects complement one another.2 Together, they can reduce your mucus-related symptoms more quickly.


Mucinex vs Robitussin

Robitussin is a cough suppressant. It reduces your urge to cough.

Mucinex makes your coughing more productive. By making your mucus thinner, Mucinex lets each cough move more mucus out of your lungs.

Mucinex and Robitussin are often used together. In fact, both brand names, Robitussin and Mucinex, offer products contain the other drug as well. Robitussin makes Robitussin Maximum Strength Cough & Chest Congestion and Mucinex makes Mucinex DM.2,5


Mucinex vs Dayquil

Dayquil contains the same active ingredient as Robitussin (dextromorphan). It is also a cough suppressant.3

Like Robitussin and Mucinex, DayQuil also offers a combination product. It is sold under the name DayQuil Cough and Congestion.3


Mucinex vs Benadryl

Similar to decongestants, Benadryl prevents the production of mucus in the first place. It does so by stopping the effects of histamine, a chemical responsible for causing the symptoms of allergies.13

Mucinex can be helpful in treating the symptoms of allergies by helping you get the mucus out of your airways once its made. Benadryl can help you prevent the symptoms in the first place.13

There is a Mucinex combination product containing Benadryl called Mucinex Sinus-Max Night. Though this product could help with your allergy symptoms, its intention is to help you sleep during a cold.14


Mucinex Drug Interactions

Mucinex Alone   

Mucinex is not known to have any reactions with other drugs.1


Mucinex Combination Products

Mucinex DM and Mucinex D may interact with a group of medications called monoamine oxidase inhibitors (MAOIs). MAOIs are a type of drug used to treat depression.2,8,15


Abuses of Mucinex

Mucinex Alone

Mucinex does not cause a high. It is extremely unlikely to be abused.9


Mucinex Combination Products

Some of the drugs in Mucinex combination products have the potential to be abused.

The cough suppressant in Mucinex DM, dextromethorphan, may cause a high similar to PCP or ketamine that some people may find addicting. Regular abuse of dextromethorphan can cause dependency. Those who try to stop using dextromethorphan after a long time may experience withdrawal symptoms.9,17

The decongestant in Mucinex D, pseudoephedrine, can be used to make an addictive drug, methamphetamine. It is fairly unlikely to be abused on its own, though it theoretically could be.18


Mucinex FAQs

  • What is an expectorant?

An expectorant is a drug that thins out the mucus in your sinuses and lungs. This makes it easier for your body to remove the mucus by coughing or blowing your nose.1

Mucinex (guaifenesin) is an expectorant.1,2


  • What is the difference between Mucinex D and Mucinex DM?

Mucinex D contains Mucinex and a decongestant, pseudoephedrine. It should be used if you have sinus pain or pressure in addition to excess mucus.2

Mucinex DM contains Mucinex and a cough suppressant, dextromorphan. It should be used if your coughs are caused by a cold or bronchitis.2


  • What is the best medicine for chest congestion and wheezing?

Mucinex was voted as the best medicine for chest congestion by regular users. They cited its high effectiveness and low cost as reasons for preferring the drug.19

Mucinex was also chosen over Robitussin by 77% of pharmacists surveyed.12


  • Will Mucinex keep you awake (can Mucinex cause insomnia)?

Insomnia is not a side effect of Mucinex.7

Some of the other drugs in Mucinex combination products, like the decongestant in Mucinex D, however, may keep you awake.1, 15


  • Will Mucinex help post-nasal drip?

Mucinex cannot stop post-nasal drip on its own. By thinning out the mucus running down your throat, however, Mucinex may make post-nasal drip less uncomfortable.1



  1. Maximum Strength Mucinex. Accessed August 22, 2017.
  2. Mucinex Products. Accessed on August 15, 2017.
  3. Dayquil Cough and Congestion. Accessed August 22, 2017.
  4. Mucinex 12-hour Chest Congestion Expectorant Tablets, 40 ct. Accessed on August 22, 2017.
  5. Robitussin: Products. Accessed August 15, 2017.
  6. Goldenberg D, Burckhardt C, Crofford L. Management of Fibromyalgia Syndrome. JAMA. 2004;292(19):2388-2395. Available at: Accessed August 15, 2017.
  7. Guaifenesin | Memorial Sloan Kettering Cancer Center. Last updated August 22, 2017. Accessed on August 22, 2017.
  8. Dextromorphan. Last revised on July 15, 2017. Accessed on August 16, 2017.
  9. Burns JM, Boyer EW. Antitussives and Substance Abuse. Subst Abuse Rehabil. 2013; 4: 75–82. Available at: Accessed on August 22, 2017.
  10. Is Guanfenesin safe during pregnancy. Accessed August 15, 2017.
  11. Guaifenesin. Published on November 23, 2010. Accessed on August 16, 2017.
  12. Cough Expectorants | Pharmacists’ Picks. Published on June 13, 2017. Accessed on August 16, 2017.
  13. No Coughing Matter. Published May 2006. Accessed August 22, 2017.
  14. Mucinex Sinus-Max Day Night Maximum Strength. Last updated on December 5, 2014. Accessed on August 16, 2017.
  15. Data Sheet: Sudomyl. Published January 17, 2012. Accessed on August 22, 2017.
  16. Assimos DG, et al. Guaifenesin- and ephedrine-induced stones. J Endourol. 1999 Nov;13(9):665-7. Available at: Accessed on August 22, 2017.
  17. Dextromorphan (DXM). Accessed August 16, 2017.
  18. Pseudoephedrine and ephedrine: managing the risk of medicines abuse. Published September 2015. Accessed August 22, 2017.
  19. 10 Best Medicines for Chest Congestion 2017. Accessed August 15, 2017.
  20. Benadryl Allergy Plus Congestion. 2016. Accessed January 21, 2018.


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