Hey There! Guaifenesin (which is a mucus thinner that is is in Mucinex) has been recommended for Fibromyalgia for a long time. I tried it and I honestly couldn't tell it helped the Fibro. It's worth a try because it has been recorded that it helps some people. I hope you are one of them! You can buy it cheaper on Amazon if you just buy Guaifenesin....Mucinex is a littler pricier. I would start out with a low dose and see how well you tolerate it.

You might want to check with your doctor to make sure it doens't coincide with any of your other meds. Blessings & Prayers.....