These Mucinex caplets contain 600mg of guaifenesin to help thin and loosen mucus, making coughs more productive. With this pack, you'll get 68 extended-release caplets. The bi-layer design allows the medication to start working quickly while also providing chest congestion relief for up to twelve hours. When you are suffering from cold and flu symptoms, this expectorant works fast to get you through the worst symptoms and on the road to recovery.