Robitussin and Mucinex are two over-the-counter remedies for chest congestion. They contain the same active ingredient and work the same way. So, why would one be a better choice for you than the other? The answer may lie in their subtle differences. Here’s a comparison of these drugs to help you make your decision.

The Robitussin product is packaged under the name Robitussin Mucus + Chest Congestion. The Mucinex products are packaged under these names:

  • Mucinex
  • Maximum Strength Mucinex
  • Children’s Mucinex Chest Congestion

How they work

Robitussin and Mucinex are two brand-name cold medicines that contain the same active ingredient, guaifenesin. Guaifenesin is an expectorant. It works by thinning mucus in your air passages. Once thinned, the mucus loosens up so you can cough it up and out.

Forms and dosage

Robitussin comes as an oral liquid. Mucinex comes as an oral liquid, as well, but is also available as:

  • oral tablets
  • maximum strength oral tablets
  • oral granules (mini-melts)

The dosage varies across forms. Read the product’s package for specific dosage information.

Both Robitussin and Mucinex can be used by people who are 12 years and older. However, Children’s Mucinex Chest Congestion liquid and mini-melts can also be used by children who are 4 years and older.

Pregnancy and breast-feeding

If you’re pregnant or breast-feeding, talk to your doctor before using either drug. Guaifenesin (the active ingredient in both Robitussin and Mucinex) has not been tested in women who are pregnant or breast-feeding. For other options, check out how to treat a cold or flu when pregnant.

Robitussin and Mucinex share the same side effects. Not all people experience side effects with these drugs. When they do happen, they usually go away as the person’s body adjusts to the medication. Check with your doctor if you have side effects that are bothersome or don’t go away.

The more common side effects of each drug include:

  • headache
  • nausea
  • vomiting

There are no reported major drug interactions with guaifenesin. However, if you take other medications, you should talk to your doctor or pharmacist before using Robitussin or Mucinex. Either one may affect the way some medications work.

Also, you should never take Robitussin and Mucinex together. Not only will this not resolve your symptoms any faster, but it could also actually hurt you. Because both of these products contain the active ingredient guaifenesin, taking them together could lead to an overdose. An overdose of guaifenesin can cause kidney problems.

There are many different products that include the brand names Robitussin and Mucinex. Read the labels and ingredients for each to make sure you select one that treats your symptoms. Use these products only as directed. Stop using them and talk to a doctor if your cough lasts more than seven days.