★★★★☆
Because I also have bronchitis/asthma, I was taking Guiafenesin and noticed a reduction in pain. I didn't know about any theories but was greatful to not have to deal with the Fibromyalgia while sick. Once the lungs cleared up and I quit taking Guiafenesin, the pain was back quadrupled. There must be something to it. I was taking Mucinex which has a higher dose of Guiafenesin in it. The terrible side effects of HEAVY perspiration and high blood pressure prohibits my taking Savella which offered pain relief but is not worth risking a stroke.
