This drug is amazing and will clear anything up. I used to get prescriptions for it before it went OTC, and it makes life with a cold so much more manageable! Highly recommended.

I was miserable for two days with bad sinus congestion, and on the third day, the stuff started to move to my chest. I took the dose as recommended, and could not believe what a difference it made. After the first day everything started to break up, and after two days, I felt great! I highly recommend this medicine.

My pulmonologist recommended Mucinex it before it was over the counter, so I have been taking it for years. It's an excellent life saver for any one that get any kind of lung congestion. Editor's note: doctor's recommendation is based on customer experience, and has not been independently verified by the drugstore.com website.

I have used Mucinex before, and it was amazing how well it worked. I had this awful cough and after 2 doses, The cough was gone. I did continue it for a couple more days, just to make sure.

A TOTAL waste of money, this product made my chest and sinus congestion much worse. I couldn't take anything else for the entire 12 hours till it was out of my system, because the pharmacist warned against mixing it with any other drug. After the most miserable 12 hours of my cold, I finally was able to take an Actifed, and felt much better. I can't believe they charge so much for this stuff.

I suffer from allergic rhinitis and sinusitis. For me this product is a godsend. I keep it on hand at all times and don't know what I would do without it. Before it was available OTC in this form, I purchased it in liquid form (liquid costs more, tastes bad, less convenient, not time release). I've been using it for a decade. It helps to ease the sinus pain and pressure so that I can usually get by without taking decongestants (which interfere with my sleep, raise my heart rate and blood pressure, etc). MOST IMPORTANT for me - Mucinex thins post nasal secretions (phlegm); this minimizes throat soreness and that uncomfortable feeling of having a "lump" in throat. It is important to note that in order to "thin" secretions, this product needs to get fluids from somewhere; therefore, you should be careful to always take it with a full glass of water (as stated on the package).

I have been treated for fibromyalgia for many years and have been on a guaifenesin treatment protocol for 2 months now. I cannot believe the rate of improvement as I was on pain relievers, muscle relaxers and doing physical therapy prior to starting this and I am now pain free and done with physical therapy off the drugs and am able to work out again! Yes, the guaifenesin treatment is 'off label' for this medication but I did much research on why it works and decided it was worth a try for me. The guaifenesin is just part of the treatment protocol. Much of my information came from guaidoc.com which is a site done by a fibromyalgia treatment center in our country.

My mom and I have used it for years (we took Humibid prior). It's a lifesaver for those with allergic rhinitis. I had 4 sinus/ear infections within 2 months. The infections ceased once I started it with Flonase. Note1: Guaifenesin works best prior to severe congestion; at that point, you should probably see a doctor. Note2: Guaifenesin is used for the treatment of fibromyalgia. It seems to 'drain' excess fluid (hence the dry mouth and frequent bathroom runs). I've given Mucinex to 5 people; all now use it. I take multiple pain meds - Mucinex interacts with none. I take 2-4 Mucinex/day -depending on the flare-ups. Consult your allergist or rheumatologist - you might have an illness which requires additional treatment with other meds or therapies. If your doctor suggests/agrees w/the use of Mucinex, use as directed; you should see results within 2 weeks or less. An infection should be treated with an antibiotic and a real decongestant - once cured, the Mucinex may be all that you need.

I had a bad chest cold that caused painful tightness in my chest and a cough and I wanted something to loosen up the tightness and I thought this product would be perfect. However after taking 2 tablets every 12 hours for two days there was absolutely no improvement. The chest tightness was still there. This product was very expensive and was a waste of money in my experience.

I got this on recommendation from a friend and have been using it the past two days in an attempt to get rid of the left-over gunk from a cold. I can say that it works really well. If you have some stuff to get rid of, definitely get this medicine.