What is guaifenesin?

Guaifenesin is an expectorant. It helps loosen congestion in your chest and throat, making it easier to cough out through your mouth.

Guaifenesin is used to reduce chest congestion caused by the common cold, infections, or allergies.

Guaifenesin may also be used for other purposes not listed in this medication guide.


You should not use this medicine if you are allergic to guaifenesin.

FDA pregnancy category C. This medication may be harmful to an unborn baby. Tell your doctor if you are pregnant or plan to become pregnant during treatment.

It is not known whether guaifenesin passes into breast milk or if it could harm a nursing baby. Do not use this medication without telling your doctor if you are breast-feeding a baby.

This medication can cause side effects that may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be awake and alert.

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Seek emergency medical attention if you think you have used too much of this medicine.

An overdose of guaifenesin is not likely to cause life-threatening symptoms.

Take the missed dose as soon as you remember. If it is almost time for your next dose, wait until then to take the medicine and skip the missed dose. Do not take extra medicine to make up the missed dose.

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Side effects

Get emergency medical help if you have any of these signs of an allergic reaction: hives; difficulty breathing; swelling of your face, lips, tongue, or throat.

Less serious side effects may include:

  • dizziness or headache,
  • a rash, or
  • nausea, vomiting, or stomach upset.

This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect. You may report side effects to FDA at 1-800-FDA-1088.

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There may be other drugs that can interact with guaifenesin. Tell your doctor about all your prescription and over-the-counter medications, vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start a new medication without telling your doctor.

Other Names

Actifed CC Chesty Cough, Altarussin, Altorant, Anti-Tuss, Aquamist, Balminil Expect Edulcore Au Sucrose, Beechams Veno's Expectorant, Beechams Veno's for Kids Chesty Cough, Benadryl Chesty Forte, Benylin Chesty Coughs, Benylin Children's Chesty Coughs, Benylin E, Benylin E Extra Strength, Benylin E Extra Strength with Menthactin, Bidex, Breonesin, Calmylin Expectorant, Diabetic Expectorant, Diabetic Tuss, Dristan Chesty Cough, Dristan Chesty Cough Guaiphenesin, Drituss G, Family Meltus Chesty Coughs, Fenesin, Fenex-LA, G Bid, GG 200 NR, GG-Cen, Ganidin NR, Genatuss, Glytuss, Gua-SR, Guaiatussin, Guaibid-LA, Guaifenex G, Guaifenex LA, Guiacough, Guiadrine G-1200, Guiatuss, Halotussin, Hill's Balsam Chesty Cough, Humavent LA, Humibid, Humibid Pediatric, Humibid e, Humigen LA, Hytuss, Iodrol NR, Iofen, Iofen-NF, Iophen NR, Jackson's Extra Strength All Fours, Jackson's The Original All Fours, Junior Meltus Chesty Coughs with Catarrh, Junior Meltus Colour and Sugar Free Expectorant, Kenkay Chesty Cough Eexpectorant, Lemsip Cough Chesty, Liqufruta Garlic Cough Medicine, Liquibid, Liquidbid 1200, Liquidbid LA, Lloydspharmacy Expectorant Adult Cough, Lloydspharmacy Expectorant Junior Cough, Lotussin, Mastussin, Mucinex, Mucinex Childrens, Mucinex Childrens Mini-Melts, Mucinex Junior Strength Mini-Melts, Muco-Fen, Muco-Fen 1200, Muco-Fen 800, Muco-Fen LA, Mucobid-L.A., MucusRelief, Mytussin, Naldecon-EX Senior, Nirolex Chesty Cough, Nyal Chesty Cough, Organidin NR, Phanasin, Pharmacist Expectorant, Pneumomist, Q-Bid LA, Q-Tussin, Respa-GF, Ri-Tussin, Robafen, Robichem, Robitussin, Robitussin Chesty Cough, Robitussin EX Colour Free, Robitussin EX Paediatric Drops, Robitussin-EX, Scot Tussin Expectorant, Scot-Tussin, Siltuss DAS, Sinumist, Sorbutuss, Strepsils Chesty Cough, T-Tussin, Tixylix Chesty Cough, Touro EX, Triaminic Chest Congestion, Tusscidin, Tussin, Tussin Expectorant, Vicks Cough Syrup for Chesty Coughs, Vicks Formula 44 for Chesty Coughs, Xpect, guaifenesin, Allfen, Amibid LA, Bidex-400, Buckley's Chest Congestion, Duratuss G, Fenesin IR, Guaifenesin LA, Guaifen NR, Mucinex Kids' Mini-Melts, Mucinex Max Strength, Organ-1 NR, Robitussin Chest Congestion, Siltussin, and Siltussin DAS-NA

Available Strengths & Dosages

Route Form Strength
oral tablet, extended release 600 mg

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