Cough
"This helped with a nasty cold when other OTC mixtures (with less guaifenesin) did not work. The 600mg tab has almost no side effects, though once in a while can make me feel woozy. Made a huge difference in loosening phlegm, helping me sleep, reduced coughing so my vocal chords are not as irritated. Also, my nasal passages cleared up significantly the first day I took it.  It&#039;s important NOT to split the tab, it is hard to swallow, but it&#039;s formulated as sustained-release.  It can&#039;t do it&#039;s job over 12 hours unless it is taken whole. Also, drinking lots of fluids (not coffee, tea) does help. Miracle drug (Mucinex)!"