Mucinex Expectorant is a 12-hour extended-release medication containing guaifenesin that helps relieve chest congestion by thinning and loosening mucus. Each package contains 20 bi-layer tablets designed to provide long-lasting relief from chest congestion. This medication works as an expectorant to help break up mucus and phlegm, making coughs more productive and easier to clear. The extended-release formula provides up to 12 hours of relief with each dose. The bi-layer tablet technology helps deliver immediate and extended relief. For proper dosage and duration of use, please consult your healthcare provider. Store at room temperature away from direct sunlight and keep out of reach of children. If symptoms persist or worsen, seek medical attention.