Free Product Added!

All ProductsPainCold & FluDigestionSleep & StressAllergyMedicine CabinetSaved CabinetsPre-Made CabinetClean Medicine Our StoryStore LocatorHealthcare Professional NetworkFrequently Asked QuestionsLogin


If you have a question or comment feel free to give us a ring at 1-855-GENEXA-1, or text us at 310-254-2339.

We’re available Monday through Friday, 8am-5pm (PST).

What Are Robitussin's Inactive Ingredients?

Understanding What's In Your Medicine

Dr. Caryn Cassidy Profile Photo

Written by Dr. Caryn Cassidy on August 9, 2021

Robitussin is one of the most well-known medicine brands in the United States. Although best known for their cough relief medications, the brand produces more than 30 different formulas designed to address a variety of different symptoms in both children and adults.

Before purchasing one of these products off the shelf of your local pharmacy, you might be wondering “what are Robitussin’s inactive ingredients and what purpose do they serve?”

What is the difference between active and inactive ingredients?

Both prescription medications and drugs sold over the counter contain both active and inactive ingredients. According to 21 Code of Federal Regulations (CFR) 210.3, Current Good Manufacturing Practice in Manufacturing, Processing, Packing or Holding of Drugs, Part (b)(7), an active ingredient is any component of a drug product that is intended to furnish pharmacological activity or other direct effect in the diagnosis, cure, mitigation, treatment, or prevention of disease, or to affect the structure or any function of the body of humans or animals.

In layman’s terms, active ingredients are the ingredients in medications that actually work to stop the symptoms you are experiencing. For example, if you’re experiencing a cough, the active ingredient in the medication would be the ingredient that actually stops you from coughing.

By contrast, 21 CFR 210.3(b)(8) defines an inactive ingredient as any component of a drug product other than the active ingredient. Inactive ingredients make up the majority (about 75 percent) of the medication and play an important role in the drug’s final look, feel, taste, and appearance.

According to Harvard Medical School, the average medication contains about nine inactive ingredients. Inactive ingredients serve many purposes in medication, including:

  • Masking the bitter taste of some medications to make them easier to swallow
  • Helping the body to absorb the drug more easily by combining with an easily digestible substance like a fatty acid
  • Binding the ingredients together to give the medicine a cohesive shape
  • Preserving the medication by preventing the growth of bacteria and fungi
  • Preventing a medication from being dissolved

What are Robitussin’s active ingredients?

Robitussin is a national brand that produces many different formulas, all of which perform a slightly different function to help relieve your cough, cold, or flu symptoms. One of the most popular is Robitussin Severe Multi-Symptom Cough, Cold and Flu Nighttime, or Robitussin CF.

Robitussin CF contains the following active ingredients in each 20 ml dose.

  • Acetaminophen, USP 650 mg
  • Diphenhydramine HCl, USP 25 mg
  • Phenylephrine HCl, USP 10 mg


Acetaminophen is a pain reliever that is commonly used for the treatment of mild to moderate pain caused by a number of different ailments, including aches and pains from the cold or flu, backaches, headaches, toothaches, osteoarthritis, menstrual periods, and more. Acetaminophen can also be used to lower a fever. When included in Robitussin CF, acetaminophen serves as a pain reliever for headache, sore throat, and minor aches and pains associated with a cold or flu and also acts as a fever reducer in patients who are experiencing a fever along with their symptoms.

Diphenhydramine HCl

Diphenhydramine HCl is an antihistamine medication that serves two purposes as part of the Robitussin CF formula. This active ingredient helps to relieve symptoms commonly associated with the common cold, including runny nose, sneezing, itchy or watery eyes,and itching of the nose and throat. It also serves as a cough suppressant for people experiencing a cough due to minor throat and bronchial inflammation and helps you fall asleep.

Phenylephrine HCl

The final active ingredient, phenylephrine HCl, serves as a nasal decongestant to help reduce nasal congestion, reduce postnasal drip, and make it easier for you to breathe while you’re sick. Because postnasal drip can cause coughing and sore throat, you may also notice improvements in these symptoms as well.

What are Robitussin’s inactive ingredients?

Robitussin CF contains the following inactive ingredients: anhydrous citric acid, artificial flavor, edetate disodium, FD&C red no. 40, glycerin, menthol, polyethylene glycol, propyl gallate, propylene glycol, purified water, sodium benzoate, sodium citrate, sorbitol solution, sucralose.

Propylene glycol, edetate disodium, and sucralose are used as binders; binders help to keep the ingredients of the medication intact. Binders generally consist of different types of sugars, including cellulose or modified cellulose. Sucralose is also used as a sweetener to help mask the bitter taste of the active ingredients and make it more palatable.

Glycerin is included in the formula as a thickening agent, a humectant, and a solvent. Because Robitussin CF is a liquid solution, glycerin helps to thicken the product and improve the consistency of the formula. Glycerin also helps to preserve foods and liquids, including medications, and it also provides sweetness to mask the bitter taste of the active ingredients.

Sodium benzoate, sodium citrate, propyl gallate, and anhydrous citric acid all act as preservatives for the medication. Sodium benzoate helps to prevent the growth of dangerous mold, yeast, and certain types of bacteria, while anhydrous citric acid functions as a natural preservative to inhibit the growth of bacteria and mold. Propyl gallate is an ester that helps to prevent oxidation. Sodium citrate is a salt-form antiseptic that also inhibits the growth of certain organisms and extends the shelf life of the product.

FD&C red no. 40 is an artificial coloring that gives the medication its well-known red color, which corresponds to the artificial cherry flavor in which the product is produced. The artificial cherry flavor is added under the term “artificial flavor,” while purified water makes up the vast majority of the product.

Menthol provides a cooling sensation that can be helpful in providing relief of minor sore throat pain. Polyethylene glycol acts as a solvent. Sorbitol is used as both a sweetener and to protect against loss of moisture content in the solution.

Are inactive ingredients associated with any risks?

Nearly every medication on the market contains some inactive ingredients. While many people focus on the contents of the active ingredients, inactive ingredients affect each person differently and should also be considered when choosing a medication. Just as a person can experience adverse effects from consuming active ingredients, they can also experience adverse effects from consuming inactive ingredients in medication.

Two of the most common risks associated with inactive ingredients in general include allergic reactions and digestive distress due to intolerances.

Allergic reactions

Allergic reactions to inactive ingredients are rare but can be potentially life threatening. At present, 38 different inactive ingredients have been identified as potential allergens, and nearly 93 percent of pills or capsules examined in one study were found to contain at least one potential allergen.

Potential allergens associated with inactive ingredients include:

  • Peanut oil
  • Chemical dyes, such as yellow 5, FD&C red 40, and others
  • Gluten (a protein found in wheat, barley, and rye

People who are severely allergic to these inactive ingredients could experience a life threatening allergic reaction called anaphylaxis, which can cause trouble breathing and can even be fatal. Others can experience skin irritation, such as itching or hives.

Inactive ingredients that are known to act as allergens include dyes like allura red, brilliant blue, and sunset yellow FCF; foods like cornstarch, gluten, lactose, peanut oil, and wheat starch; and sweeteners like aspartame, mannitol, saccharin, and sucrose.

Digestive distress

People who are sensitive to inactive ingredients but who are not directly allergic to them may experience digestive distress. These symptoms are most commonly associated with ingredients known as FODMAPs, which stands for fermentable oligosaccharides, disaccharides, monosaccharides, and polyols.

Each of these ingredients contains sugars that are hard for the body to digest and can cause digestive distress, including symptoms like bloating, gas, and diarrhea. Researchers have found that 55 percent of all oral medications include at least one FODMAP, with artificial sweeteners being a common culprit.

Your risk of experiencing adverse effects associated with inactive ingredients increases as you take multiple different types of medication with a variety of different inactive ingredients. Patients who take more medications are more likely to experience these effects.


Although Robitussin produces many different formulas, common active ingredients include acetaminophen, diphenhydramine HCl, and phenylephrine HCl. Robitussin CF contains the following inactive ingredients: anhydrous citric acid, artificial flavor, edetate disodium, FD&C red no. 40, glycerin, menthol, polyethylene glycol, propyl gallate, propylene glycol, purified water, sodium benzoate, sodium citrate, sorbitol solution, sucralose. Inactive ingredients are found in all medications but can cause allergic reactions or digestive distress in some people.