Robitussin CF Dosages: Your GoodRx Guide

If you’ve come down with a cold or the flu, you’re likely looking for symptom relief. And tackling multiple symptoms with one medication may be more convenient for you. Perhaps you’re considering Robitussin CF, a popular over-the-counter (OTC) liquid cough syrup.

But Robitussin CF isn’t just one medication; it’s a line of medications. Each product in the line has different active ingredients. Do the different products have different instructions? Below, we’ll discuss typical Robitussin CF dosages for each product in the line.

What’s the typical Robitussin CF dosage for adults?

The typical Robitussin CF dosage for adults is 20 mL by mouth every 4 hours as needed. You shouldn’t take more than 6 doses (120 mL) in 24 hours. But as we’ll detail below, each Robitussin CF product has different active ingredients. It’s a good idea to read the OTC label of your selected product to know what it contains.

Robitussin CF comes with a dose cup for you to use. Avoid using a household spoon to measure out medication. These are inaccurate and can cause you to take too much or not enough medication. If you lose the provided dose cup, ask your pharmacist about a replacement.

Good to know: Some Robitussin CF products contain the nasal decongestant phenylephrine. In September 2023, the FDA announced that oral phenylephrine is likely ineffective for nasal congestion. Phenylephrine isn’t harmful, but there are more effective nasal decongestants available.

Robitussin CF Max dosage for adults

Every 20 mL of Robitussin CF Max contains:

• 650 mg of acetaminophen (a pain reliever and fever reducer)

• 20 mg of dextromethorphan (a cough suppressant)

• 400 mg of guaifenesin (an expectorant)

• 10 mg of phenylephrine

The typical Robitussin CF Max dosage for adults is 20 mL by mouth every 4 hours as needed. Don’t take more than 6 doses in 24 hours.

Robitussin Honey CF Max dosage for adults

Each 20 mL of Robitussin Honey CF Max contains:

• 650 mg of acetaminophen

• 20 mg of dextromethorphan

The typical Robitussin Honey CF Max dosage for adults is 20 mL by mouth every 4 hours as needed. Don’t take more than 6 doses in 24 hours.

Good to know: Although honey can help to soothe a cough, the honey in Robitussin CF products is added for flavoring only.

Robitussin Honey CF Nighttime Max dosage for adults

Each 20 mL of Robitussin Honey CF Nighttime Max contains:

• 650 mg of acetaminophen

• 25 mg of diphenhydramine (an antihistamine that helps with runny nose and promotes sleep)

EXPERT PICKS: WHAT TO READ NEXT

• Choosing the best cough medication: There are many prescription and over-the-counter cough medications available, but studies show they don’t all work. So which one should you take?

• Using a sweet home remedy: It turns out that honey may have some science-backed benefits to help soothe a cough.

• Seeking medical care: Should you see a health professional for that cough? Knowing when to seek treatment can help you avoid more serious health issues.

The typical Robitussin Honey CF Nighttime Max dosage for adults is 20 mL by mouth every 4 hours as needed. Don’t take more than 6 doses in 24 hours.

What’s the typical Robitussin CF dosage for children?

Adolescents age 12 and older can follow the adult Robitussin CF dosage instructions listed above. For kids under 12, there’s a children’s version of Robitussin CF available. You can safely give it to children age 4 and older.

Every 10 mL of Children’s Robitussin CF contains:

• 10 mg of dextromethorphan

• 100 mg of guaifenesin

• 5 mg of phenylephrine

Children’s Robitussin CF dosages are based on a child’s age (not body weight). The dosage instructions for each age group are listed below:

• Age 12 and older: Give 20 mL by mouth every 4 hours as needed. Don’t give more than 6 doses (120 mL) in 24 hours.

• Age 6 to 11: Give 10 mL by mouth every 4 hours as needed. Don’t give more than 6 doses (60 mL) in 24 hours.

• Age 4 to 5: Give 5 mL by mouth every 4 hours as needed. Don’t give more than 6 doses (30 mL) in 24 hours.

• Under 4 years old: The medication is not recommended.

Are there any dosage adjustments for health conditions?

For some medications, dosage adjustments are recommended if you have certain health conditions, such as kidney or liver disease. This isn’t the case for Robitussin CF. But there are people who may need to avoid it altogether. Usually, they have a greater risk for serious side effects when taking the medication.

Ask a healthcare professional before taking Robitussin CF if you:

• Are pregnant or breastfeeding

• Have diabetes

• Have glaucoma

• Have a heart condition or high blood pressure

• Have liver disease

• Drink 3 or more alcoholic beverages per day

• Have thyroid problems

• Trouble urinating due to an enlarged prostate gland

• Have excessive amounts of mucus with your cough

• Take other medications that contain acetaminophen or an antihistamine, such as diphenhydramine

• Take medications that cause drowsiness, such as sleep aids or opioid pain relievers

• Have taken a monoamine oxidase inhibitor, such as selegiline (Emsam, Zelapar), in the last 2 weeks

• Have a long-term cough caused by smoking, asthma, or chronic obstructive pulmonary disease

This isn’t a complete list of people who should speak with a healthcare professional before taking Robitussin CF. It’s a good idea to check with your healthcare team beforehand if you take any medications or have any health conditions. They can tell you if you can safely take Robitussin CF.

What should you do if you take too much Robitussin CF?

Taking an extra dose of Robitussin CF by accident likely won’t cause serious harm for most people. But you may experience more side effects. Each active ingredient has different side effects. But drowsiness, dizziness, and stomach upset are common.

Taking an excessive amount of Robitussin CF can be more concerning. Too much acetaminophen can contribute to liver damage. Too much phenylephrine can raise your blood pressure or heart rate. And too much dextromethorphan or diphenhydramine can cause hallucinations, seizures, or even death.

If you’re unsure whether you’ve taken too much Robitussin CF, contact a health professional or call Poison Control at 1-800-222-1222 for guidance. If you know you’ve taken too much, seek medical attention right away at the ER or call 911.

How to save on Robitussin CF

There are ways to save on Robitussin CF products, which are available as brand-name and generic medications. If a healthcare professional writes you a prescription for Robitussin CF, GoodRx may help you save over 20% off the average retail price. The price of a 118 mL bottle of Robitussin CF at certain pharmacies may cost as low as $7.29 with a free GoodRx coupon.

Why trust our experts?

Written by:

Sarah Morin, RPh

Sarah Morin, RPh, has been a registered pharmacist for over 25 years. She started out as a hospital pharmacist, working at Rhode Island Hospital and then at the University of Connecticut Health Center.

Edited by:

Christina Aungst, PharmD

Christina Aungst, PharmD, is a pharmacy editor for GoodRx. She began writing for GoodRx Health in 2019, transitioning from freelance writer to editor in 2021.

Reviewed by:

Austin Ulrich, PharmD, BCACP

Austin Ulrich, PharmD, BCACP, is a board-certified ambulatory care clinical pharmacist. In his early career, he provided direct patient care in a variety of settings, including hospital and community pharmacies, and in a primary care clinic as a clinical pharmacist.

Our editorial standards

Meet our experts