Guaifenesin is an ingredient in cough and cold medicines that is used to help clear mucus or phlegm from your chest when you have had a cold or flu. Guaifenesin works by making your mucus thinner and easier to cough up, which helps clear chest congestion. Guaifenesin is available as an over-the-counter (OTC) medicine and also available on prescription.

Guaifenesin is not FDA approved for treatment of fibromyalgia but some people take it off-label for this condition.  In clinical studies guaifenesin has not shown to be effective for fibromyalgia.

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

Use this medicine exactly as directed on the label, or as prescribed by your doctor. Do not use it in larger amounts or for longer than recommended.

Guaifenesin is commonly found as part of over-the-counter combination medications for cold and cough. Read labels or ask a doctor or pharmacist before using any other cold, or cough medicine when taking guaifenesin.

Always ask a doctor before giving a cough or cold medicine to a child. Death can occur from the misuse of cough and cold medicines in very young children.

Drink extra fluids to help loosen the congestion and lubricate your throat while you are taking this medication. This medication may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.

Use guaifenesin exactly as directed on the label, or as prescribed by your doctor. Do not use in larger or smaller amounts or for longer than recommended. Cough medicine is usually taken only for a short time until your symptoms clear up.

Take guaifenesin with food if it upsets your stomach.

Measure liquid medicine with the dosing syringe provided, or with a special dose-measuring spoon or medicine cup. If you do not have a dose-measuring device, ask your pharmacist for one.

Do not crush, chew, break, or open a controlled-release, delayed-release, or extended-release tablet or capsule. Swallow it whole. Breaking or opening the pill may cause too much of the drug to be released at one time.

Drink extra fluids to help loosen the congestion and lubricate your throat while you are taking this medication.

Store at room temperature away from moisture, heat, and light.

Usual Adult Dose for Cough:

Immediate release formulation: 200 to 400 mg orally every 4 hours as needed, not to exceed 2.4 g/day

Sustained release formulation: 600 to 1200 mg orally every 12 hours, not to exceed 2.4 g/day

Usual Pediatric Dose for Cough:

Immediate release formulation:

less than 2 years: 12 mg/kg/day orally in 6 divided doses

2 to 5 years: 50 to 100 mg orally every 4 hours as needed, not to exceed 600 mg/day

6 to 11 years: 100 to 200 mg orally every 4 hours as needed, not to exceed 1.2 g/day

12 years or older: 200 to 400 mg orally every 4 hours as needed, not to exceed 2.4 g/day

Sustained release formulation:

2 to 5 years: 300 mg orally every 12 hours, not to exceed 600 mg/day

6 to 11 years: 600 mg orally every 12 hours, not to exceed 1.2 g/day

12 years or older: 600 to 1200 mg orally every 12 hours, not to exceed 2.4 g/day

Ask a doctor or pharmacist if it is safe for you to use this medicine if you have other medical conditions, such as liver disease, kidney disease, or phenylketonuria (PKU).

It is not known whether guaifenesin will harm an unborn baby. Ask a doctor before using this medicine if you are pregnant.

It is not known whether guaifenesin passes into breast milk or if it could harm a nursing baby. Ask a doctor before using this medicine if you are breast-feeding a baby.

Do not give this medicine to a child without medical advice.

Since cough or cold medicine is taken when needed, you may not be on a dosing schedule. If you are taking the medication regularly, take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Keep this medication in the container it came in, tightly closed, and out of reach of children. Store it at room temperature and away from excess heat and moisture (not in the bathroom).

Unneeded medications should be disposed of in special ways to ensure that pets, children, and other people cannot consume them. However, you should not flush this medication down the toilet. Instead, the best way to dispose of your medication is through a medicine take-back program. Talk to your pharmacist or contact your local garbage/recycling department to learn about take-back programs in your community. See the FDA's Safe Disposal of Medicines website (http://goo.gl/c4Rm4p) for more information if you do not have access to a take-back program.

It is important to keep all medication out of sight and reach of children as many containers (such as weekly pill minders and those for eye drops, creams, patches, and inhalers) are not child-resistant and young children can open them easily. To protect young children from poisoning, always lock safety caps and immediately place the medication in a safe location – one that is up and away and out of their sight and reach. http://www.upandaway.org

Drink plenty of fluids while you are taking this medication.

Unless your doctor tells you otherwise, continue your normal diet.

This medication may impair your thinking or reactions. Be careful if you drive or do anything that requires you to be alert.

Ask a doctor or pharmacist before using any other cold, or cough medicine. Many combination medicines contain guaifenesin. Taking certain products together can cause you to get too much of a certain drug. Check the label to see if a medicine contains guaifenesin.

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

Common guaifenesin side effects may include:

• dizziness, headache;

• drowsiness;

• rash; or

• nausea, vomiting, stomach upset.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

Ask your pharmacist any questions you have about guaifenesin.

It is important for you to keep a written list of all of the prescription and nonprescription (over-the-counter) medicines you are taking, as well as any products such as vitamins, minerals, or other dietary supplements. You should bring this list with you each time you visit a doctor or if you are admitted to a hospital. It is also important information to carry with you in case of emergencies.

• Adult Tussin DM® (containing Dextromethorphan, Guaifenesin)
• Aldex® (containing Guaifenesin, Pseudoephedrine)
• Biocotron® (containing Dextromethorphan, Guaifenesin)
• Biospec® (containing Dextromethorphan, Guaifenesin)
• Bisolvine® (containing Dextromethorphan, Guaifenesin)
• Care One Chest Congestion Relief® (containing Dextromethorphan, Guaifenesin)
• Certuss® (containing Chlophedianol, Guaifenesin)
• Cheratussin AC® (containing Codeine, Guaifenesin)
• chest congestion® (containing Dextromethorphan, Guaifenesin)
• Childrens Mucus Relief® (containing Dextromethorphan, Guaifenesin)
• Childrens Mucus Relief Cherry® (containing Dextromethorphan, Guaifenesin)
• Childrens Mucus Relief Cough Cherry® (containing Dextromethorphan, Guaifenesin)
• Childrens Relief Cherry® (containing Dextromethorphan, Guaifenesin)
• Chlo Tuss® (containing Chlophedianol, Guaifenesin)
• Codar® (containing Codeine, Guaifenesin)
• Cough® (containing Dextromethorphan, Guaifenesin)
• Cough Syrup® (containing Dextromethorphan, Guaifenesin)
• CounterAct® (containing Dextromethorphan, Guaifenesin)
• CVS Chest Congestion Relief® (containing Dextromethorphan, Guaifenesin)
• Dex-Tuss® (containing Codeine, Guaifenesin)
• DG Health Childrens Mucus Relief Cough® (containing Dextromethorphan, Guaifenesin)
• DG Health Tussin DM® (containing Dextromethorphan, Guaifenesin)
• Diabetic Tussin DM® (containing Dextromethorphan, Guaifenesin)
• Diabetic Tussin DM Maximum Strength® (containing Dextromethorphan, Guaifenesin)
• Donatussin Drops® (containing Guaifenesin, Phenylephrine)
• Double Tussin Intense Cough Reliever® (containing Dextromethorphan, Guaifenesin)
• Equaline Adult Tussin® (containing Dextromethorphan, Guaifenesin)
• Equaline Tussin Cough and Chest Congestion® (containing Dextromethorphan, Guaifenesin)
• Equate Tussin DM® (containing Dextromethorphan, Guaifenesin)
• Expectorant Plus Cough Relief® (containing Dextromethorphan, Guaifenesin)
• FormuCare Cough Syrup DM® (containing Dextromethorphan, Guaifenesin)
• Freds Chest Congestion Relief® (containing Dextromethorphan, Guaifenesin)
• Good Neighbor Pharmacy Adult Tussin® (containing Dextromethorphan, Guaifenesin)
• Good Neighbor Pharmacy Tussin DM® (containing Dextromethorphan, Guaifenesin)
• Good Neighbor Pharmacy Tussin DM Max® (containing Dextromethorphan, Guaifenesin)
• Good Sense Childrens Mucus Relief Cough® (containing Dextromethorphan, Guaifenesin)
• Good Sense tussin® (containing Dextromethorphan, Guaifenesin)
• Good Sense Tussin DM® (containing Dextromethorphan, Guaifenesin)
• Guaiasorb DM® (containing Dextromethorphan, Guaifenesin)
• Guaiatussin AC® (containing Codeine, Guaifenesin)
• Guiatuss DM® (containing Dextromethorphan, Guaifenesin)
• Healthy Accents Tussin DM® (containing Dextromethorphan, Guaifenesin)
• Iophen C NR® (containing Codeine, Guaifenesin)
• Iophen DM NR® (containing Dextromethorphan, Guaifenesin)
• Leader Adult Tussin DM® (containing Dextromethorphan, Guaifenesin)
• Leader Childrens Mucus Relief Cough® (containing Dextromethorphan, Guaifenesin)
• Leader Intense Cough Reliever® (containing Dextromethorphan, Guaifenesin)
• Leader Tussin DM Max® (containing Dextromethorphan, Guaifenesin)
• Lusair® (containing Guaifenesin, Phenylephrine)
• Mucinex Fast-Max® (containing Dextromethorphan, Guaifenesin)
• Mucus Relief Cough® (containing Dextromethorphan, Guaifenesin)
• Mucus Relief DM® (containing Dextromethorphan, Guaifenesin)
• Nature Fusion® (containing Dextromethorphan, Guaifenesin)
• PediaCare Childrens Cough and Congestion® (containing Dextromethorphan, Guaifenesin)
• Premier Value Chest Congestion and Cough Relief® (containing Dextromethorphan, Guaifenesin)
• Primatene® (containing Ephedrine, Guaifenesin)
• Q Tussin DM® (containing Dextromethorphan, Guaifenesin)
• RelCof-C® (containing Codeine, Guaifenesin)
• Robafen DM Max® (containing Dextromethorphan, Guaifenesin)
• Robitussin Cough and Chest Congestion DM® (containing Dextromethorphan, Guaifenesin)
• Safetussin® (containing Dextromethorphan, Guaifenesin)
• Scot-Tussin Senior SF DMExp® (containing Dextromethorphan, Guaifenesin)
• Smart Sense Mucus Relief Cough® (containing Dextromethorphan, Guaifenesin)
• Smart Sense tussin dm max® (containing Dextromethorphan, Guaifenesin)
• Sun Mark Mucus Relief Cough® (containing Dextromethorphan, Guaifenesin)
• Sun Mark Tussin DM® (containing Dextromethorphan, Guaifenesin)
• Sunmark Tussin DM® (containing Dextromethorphan, Guaifenesin)
• Topcare Mucus Relief® (containing Dextromethorphan, Guaifenesin)
• Topcare tussin dm® (containing Dextromethorphan, Guaifenesin)
• Topcare Tussin DM Max® (containing Dextromethorphan, Guaifenesin)
• Tussin Cough DM® (containing Dextromethorphan, Guaifenesin)
• Tussin DM® (containing Dextromethorphan, Guaifenesin)
• Up and Up Adult Cough Formula DM® (containing Dextromethorphan, Guaifenesin)
• Up and Up Childrens Mucus Relief and Cough® (containing Dextromethorphan, Guaifenesin)
• Vanacof® (containing Chlophedianol, Guaifenesin)
• Vicks® DayQuil® (containing Dextromethorphan, Guaifenesin)
• Wal Tussin DM® (containing Dextromethorphan, Guaifenesin)
• Z-Cof 1® (containing dextromethorphan and Guaifenesin, Pseudoephedrine)
• Zicam® (containing acetaminophen and Dextromethorphan, Guaifenesin)
• Zodryl DEC® (containing pseudoephedrine and Codeine, Guaifenesin)
• Zyncof® (containing Dextromethorphan, Guaifenesin)