The only Mucinex recommended for longer-term use is the pure guaifenesin version. Usually Mucinex 600 mg, sometimes 1200 mg. It is extended release (labelled ER, LA or 12-hour) & used twice a day.

Those containing a decongestant or cough suppressant are meant for short term use only. Short term use Mucinex includes Mucinex DM, Mucinex Sinus, Mucinex FastMax, Mucinex Night Shift and whatever other variations that you see.

Mucinex is available cheaper on-line if you decide to take it long term - it is very pricy in the drug & discount stores. You can also find generic versions - labelled guaifenesin extended release, for significantly less - I am using my third generic brand without any noticeable difference between any of them & the name brand. The short term version may be cheaper, but needs to be taken about every 6 hours for maximum effect, and I find that a pain in the b....
Sue

Sue