GUAIFENESIN (Mucinex): What is used for?

What is Guaifenesin?

Guaifenesin (Guaifenesina) is an active ingredient used to treat cough and runny nose.

The brand names of Guaifenesin in the United States are: Mucinex, Robitussin Chest Congestion, Robafen, Tussin.

Mechanism of action (MOA) 

Reduces viscosity and facilitates the elimination of secretions, increasing fluid expectoration in the respiratory tract.

Therapeutic indications, uses and benefits 

  • Respiratory conditions with expectoration.
  • Cough.

Dosage of Guaifenesin


  • Syrup 20 mg/ml. Adults and children > 12 years: 10 ml 4 times/day.
  • Syrup 66.6 mg/5 ml. Adults and children > 12 years: 15 ml; children 6-11 years: 10 ml; every 4 or 6 h.
  • Syrup 0,65 g/100 ml. Adults: 15 ml; 3-4 times/day.

Drink a glass of water after each dose. Do not exceed recommended dose.



Warnings and precautions

  • Do not use in persistent or chronic cough due to asthma or when accompanied by excessive secretion, unless medically indicated.
  • Clinical evaluation if the cough persists after 7 days of treatment.
  • Severe liver or kidney disease; concomitant use with cough suppressants.


False increase of 5-hydroxyindolacetic acid with nitroso-naphthol reagent and vanilmandelic acid, in urine.

To suppress administration 48 h before.


Not recommended, insufficient information.


It is not known whether this medicine is excreted through breast milk.

Adverse reactions and side effects 

Gastrointestinal discomfort, nausea, vomiting; hypersensitivity reactions.


Source: The content of this active ingredient has been written taking into account the clinical and molecular information of all medicines authorised and marketed in the United States under the Unique Ingredient Identifier (UNII) by the Substance Registration System (SRS) of the Food and Drug Administration (FDA) and the United States Pharmacopeia (USP).

In order to know in detail the information authorized by the FDA for each drug, you should consult the corresponding medication guide authorized by the FDA.


UNII: 495W7451VQ
PubChem CID: 3516
NCI Thesaurus: C29081

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