Mucinex Maximum Strength 12-Hour Chest Congestion Expectorant Tablets, 1200 mg Guaifenesin, 14 Extended Release Tablets Sale! from 1589 1907 /per Qty. Add to Cart This item is currently on backorder but you can still purchase it now and we'll ship as soon as more become available. Maximum Strength Chest Congestion Medicine Thins & loosens mucus with active ingredient guaifenesin expectorant Relieves Chest Congestion Mucinex contains a unique bi-layer tablet, one side immediately releases and the other side is an extended release that lasts up to 12 hours Qty available:60 Tweet