Contac is the OTC expectorant and that doctors trust for themselves and their families. Alleviates Symptoms: Guaifenesin is an expectorant that helps loosen phlegm to reduce chest congestion caused by colds, infections or irritants. Fast Acting & Long Lasting: Features a unique extended-release tablet, one part of the tablet will release immediately, while the other part will provide an extended release so the medicine starts to release right away and lasts for up to 12 hours. Congestion Relief: This maximum-strength expectorant relieves chest congestion caused by excess mucus by making your cough more productive. Cough Suppressant & Expectorant: Clinically proven to last up to 12 hours, this medicine contains Dextromethorphan HBr for powerful relief for your toughest chest congestion, controlling cough while thinning and loosening mucus.