The brand Robitussin names several different products that treat cough and cold symptoms. Most people can use these products safely and without side effects. Sometimes, though, side effects can happen when you use Robitussin. Here’s what to know.

Robitussin is an over-the-counter cough medicine for adults and children who are older than 12 years. The active ingredient in Robitussin is an expectorant called guaifenesin. Expectorants help thin secretions from your lungs and loosen phlegm or mucus. These effects can lead to a productive cough. In other words, they help you cough the mucus up and out.

Most people tolerate Robitussin when they take it at recommended doses. But in some cases, side effects can happen. Some of these side effects are more common than others, though all of them are rare. They can happen even when you use Robitussin at the recommended dosage. But more often, they happen when you use too much.

Common side effects

The more common side effects of the Robitussin ingredient guaifenesin can include:

  • headache
  • nausea
  • vomiting
  • stomach pain
  • diarrhea

These are the most common side effects reported with guaifenesin, but they are still rare. Most people will not experience these side effects unless the dosage of guaifenesin is higher than what’s typically recommended.

If you do experience stomach-related side effects, try taking Robitussin with food. This may help decrease your symptoms.

Serious side effects

There are no serious side effects associated with the use of guaifenesin. As with any drug, there’s always the risk of an allergic reaction. You should not take any Robitussin product if you already know you’re allergic to guaifenesin.

A rash on your skin, swelling of your tongue or lips, and trouble breathing can all be symptoms of an allergic reaction. If you notice these symptoms after you take Robitussin, contact your doctor right away. If you feel that these symptoms are life-threatening, call 911 immediately.

Side effects from overuse

You may also experience side effects if you take too much Robitussin. Kidney stones are the biggest risk of taking too much for an extended period. Symptoms of kidney stones include:

  • extreme pain that won’t go away in your back or side
  • blood in your urine
  • fever and chills
  • vomiting
  • urine that smells bad or looks cloudy
  • a burning feeling when you urinate

Contact your doctor right away if you experience any of these symptoms.

Generally, most people can use Robitussin without having side effects. You can help reduce your chances of side effects by following the dosage instructions and using Robitussin correctly. Try following these tips for safe use:


  • Do take the recommended amount of Robitussin.
  • Do take Robitussin with food to minimize stomach-related side effects such as diarrhea, nausea, vomiting, and stomach pain.


  • Don’t use Robitussin to treat a cough caused by smoking, asthma, chronic bronchitis, or emphysema.
  • Don’t use Robitussin for longer than seven days.
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