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Contact: Kris Kuykendall

Study Shows No Benefit from Active Ingredient in Common Cold Medicine

(Irving, TX—May 8, 2014) Glyceryl guaiacolate ether (GGE) is unlikely to make it easier to cough up phlegm when delivered in the recommended dose. GGE is approved by the FDA as an over-the-counter expectorant and is the active ingredient in Mucinex extended-release and many other cold remedies on the market.

The study was published in the May 2014 issue of RESPIRATORY CARE, a journal of the American Association for Respiratory Care.

A total of 295 subjects completed the 8-day, multi-center clinical trial in which sputum samples were collected and measured for their volume and properties. At the end of the study, authors concluded that “extended-release GGE (Mucinex) administered at the recommended dose is no more effective than a placebo in changing sputum properties.”

Bruce Rubin, MD, chair of pediatrics at the Virginia Commonwealth University Medical Center and a lead author in the study, said, “This study is consistent with smaller studies that have shown that guaifenesin has no measurable effect on sputum properties or mucus clearance when taken by otherwise healthy adults who get a common cold.”

Other studies have also failed to find a benefit in the use of GGE. In studying the sputum properties of test subjects, researchers found neither expectorant nor mycolytic (thinning or breaking down of the mucus) benefit to GGE. If GGE were an expectorant, researchers would expect to find increased sputum volume and hydration. If GGE were a mucolytic, they would expect to find decreased elasticity of the mucus.

Rubin said, “Although we did not study people with chronic bronchitis or other mucus problems, it is very unlikely that any benefit perceived by people who take medications containing guaifenesin is due to clearing out airway mucus.”


RESPIRATORY CARE is a science journal published by the American Association for Respiratory Care. It has been in continuous publication since 1956. www.rcjournal.com

American Association for Respiratory Care is a 52,000-member professional association representing respiratory therapists and others who care for patients with pulmonary disease. www.aarc.org

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