Guaifenesin

What is guaifenesin?

Guaifenesin is an expectorant—a type of cough medication that thins and loosens the mucous in your chest to make it easier to cough up the mucous. Guaifenesin is the active ingredient in most Mucinex and Robitussin products, among others. The label on your medication will tell you if it includes guaifenesin.

Guaifenesin is a very safe medication and taking too much is not harmful. However, many medications that contain guaifenesin include other active ingredients, such as acetaminophen, that may be harmful if you take too much.

Guaifenesin is not recommended for children under 4 years old. Here are a few ways you can help a younger child feel better when they have a cold.

What happens if someone takes too much guaifenesin?

The person will be fine. Taking too much guaifenesin will not cause any symptoms.

However, many medications that contain guaifenesin include other active ingredients, some of which can be harmful if someone takes too much. See our cold medication page for information on some of the other ingredients that may be in your medication.

What should I do if someone has taken too much guaifenesin?

You do not need to do anything. You may want to give the person a little bit of water to wash the taste out. If you are worried, or if the medication has other active ingredients, call the poison center at 1-800-222-1222, chat online or text POISON to 85511.

How can I prevent medication poisonings?

Use medications safely:

• Always read the label on your medication bottles. It will tell you what the medication is and how much to take. Check the label each time you take the medication.
• If you have any questions about your medication, ask your doctor or pharmacist or contact the poison center—call 1-800-222-1222, chat online or text POISON to 85511.
• If you are taking more than one medication, keep track of them with a written schedule. Also keep a medication list to share with your doctors and pharmacist.

Store medications safely:

• Always keep medication in its original container, or in a child-resistant pill reminder box. Never store medication in a household container like a sandwich bag or a film canister.

Get rid of medications safely:

• Get rid of unwanted or expired medication. See our medication disposal page for more information.

See our medication page for more medication safety tips, including information on keeping young children and teens safe.