Chest congestion happens when mucus builds up in your lungs ... Guaifenesin is the active ingredient in several common expectorants, including Mucinex and Robitussin. It is a safe and effective drug ...

It is most commonly sold as a syrup but can be found as capsules and lozenges. If you have a productive ('wet") cough, it is usually more beneficial to cough mucus out of your lungs rather than trying ...