Guaifenesin (pronounced “gwai-feh-nuh-sun”) is an expectorant that is nearly universally found in over-the-counter cold, flu, cough, and other combination medications. People less commonly buy guaifenesin by itself, but standalone guaifenesin can be found on store shelves labeled as “mucus relief,” “mucus relief ER,” or “chest congestion.” These products are likely extended-release versions of guaifenesin that conveniently require only one dose to be taken every twelve hours. Extended-release guaifenesin is too strong for children younger than 12. Use immediate-release guaifenesin tablets or liquid instead.
Check our best Guaifenesin prices
Guaifenesin overview
BRAND NAMES:
Mucinex, Contac Chest Congestion, Air-Power
Generic Names:
Guaifenesin
Uses:
Thins mucus so you can clear it from your head, throat, and lungs
Therapeutic Classes:
Expectorant
Forms:
Tablet, extended-release tablet, oral solution (liquid)
How it’s taken:
By mouth
What is Guaifenesin used for?
Guaifenesin relieves chest congestion by thinning mucus in the lungs.
What form(s) does Guaifenesin come in
Tablet
200 mg
400 mg
Extended-release tablet
600 mg
1,200 mg
Liquid
100 mg/5 mL
What are common Guaifenesin doses?
For chest congestion:
In adults and children 12 years of age and older: 200–400 mg immediate-release guaifenesin (tablets or 2–4 teaspoons oral solution) every 4 hours OR 600–1,200 mg extended-release tablets every 12 hours
In children 6–11 years of age and older: 100–200 mg immediate-release guaifenesin (½–1, 200 mg tablet OR 1–2 teaspoons oral solution) every 4 hours
In children 2–5 years of age and older: 50–100 mg immediate-release guaifenesin (½–1 teaspoon oral solution) every 4 hours
Find more detailed information about guaifenesin dosage, forms, and strengths here.
Common Guaifenesin prescriptions
guaiFENesin
100 tablets bottleguaiFENesin
20 tablets bottleguaiFENesin
30 tablets bottleguaiFENesin
473ml of 100mg/5ml bottleguaiFENesin
500 tablets bottleguaiFENesin
60 tablets bottleguaiFENesin
400mg tablet
How to take Guaifenesin
Follow the instructions on the medication label. Do not take more than directed or exceed the maximum daily dosage.
How to take guaifenesin tablets:
Take the tablet with a full glass of water.
Swallow the tablet whole. Do not crush, chew, or break the tablet.
Store guaifenesin tablets at room temperature.
How to take guaifenesin oral solution:
Liquid or syrup guaifenesin products include a measured dosing cup, so measure each dose with the dosing cup.
You can also measure doses using measuring spoons. Most guaifenesin labels give dosing instructions in teaspoons (1 teaspoon = 100 mg).
The entire dose should be swallowed.
Store guaifenesin liquid at room temperature.
To help guaifenesin loosen mucus in the lung’s airways, drink extra fluids throughout the day and use a humidifier or steam vaporizer to keep the air moist.
What to do if you miss a dose of Guaifenesin
Take a missed dose when remembered.
If you take a missed dose, take the next dose at least four hours later (for immediate-release guaifenesin) or 12 hours later (for extended-release guaifenesin).
Do not take an extra dose to make up for a missed dose.
Guaifenesin contraindications
You should not use this medicine if you have ever had an allergic reaction to guaifenesin.
Guaifenesin warnings
Tell any healthcare provider who treats you that you are using this medicine.
If pregnant or breastfeeding, consult with a healthcare provider before using guaifenesin.
Before using guaifenesin, talk to a healthcare provider if you have:
A cough with too much phlegm
A chronic cough due to smoking, asthma, emphysema, or bronchitis
Guaifenesin is a common ingredient in many non-prescription combination drugs (like cold or flu medications). To avoid an accidental overdose, always check the ingredients of combination medications before taking guaifenesin or any other OTC medication.
Chest congestion and coughing may be symptoms of a more serious or chronic illness. If phlegm and coughing persist for longer than seven days or there are other symptoms, such as rash or fever, see a healthcare provider.
Some guaifenesin liquids contain aspartame, which may cause a serious reaction in people with phenylketonuria.
Guaifenesin interactions
Guaifenesin has no known drug interactions.
Guaifenesin side effects
Nausea
Vomiting
Headache
Diarrhea
Rash
Drowsiness
Sources:
Guaifenesin drug summary, Prescriber’s Digital Reference (PDR)
Guaifenesin extended-release tablet drug information, DailyMed (NIH National Library of Medicine)
Guaifenesin liquid drug information, DailyMed (NIH National Library of Medicine)
Guaifenesin tablet drug information, DailyMed (NIH National Library of Medicine)
Subscribe to our savings newsletter
Health education, drug info, wellness & more
By clicking 'Subscribe', I agree to SingleCare's Terms & Conditions.
