Compare to Mucinex active ingredient. Say goodbye to mucus and chest congestion with Mucus and Chest Congestion Relief Guaifenesin Extended-Release Tablets, 600 mg. Just one dose releases the medicine you need immediately and lasts for up to 12 hours to help loosen phlegm (mucus) and thin bronchial secretions in the airways to make wet coughs more productive. Clear bothersome excess mucus and avoid frequent doses of cold medicine. This expectorant relieves chest congestion and mucus for up to 12 hours so you have quick and long-lasting cough relief. This regular strength chest congestion relief medicine is for adults and children 12 years of age and older. The product is Gluten Free.