The Guaifenesin Protocol for Fibromyalgia

When you look online for fibromyalgia treatments, it's common to come across references to guaifenesin, which is the drug in Mucinex. The Guaifenesin Protocol for treating fibromyalgia (FMS) is based on a theory that is as yet unproven and is not supported by most FMS experts.

A woman looking at her pill bottle
Daniela Jovanovska-Hristovska / Getty Images

What Is the Guaifenesin Protocol?

The Guaifenesin Protocol was developed by Paul St. Amand, MD, an endocrinologist who has FMS, as do several members of his family. At its root is the theory that our cells aren't able to make enough energy because of low levels of adenosine triphosphate (ATP), and that energy deprivation leads to the many symptoms of FMS. Some research does support this theory. However, this next step is where St. Amand diverges from the rest of the medical community.

He says the bodies of people with FMS accumulate too much of the mineral phosphate, which supports your body's metabolism and performs many vital functions. This, he says, is what leads to underproduction of ATP. St. Amand believes the drug guaifenesin makes your kidneys pull excess phosphates from your cells, thereby reversing the process he says causes fibromyalgia.

Guaifenesin is on the market in several forms and is primarily an expectorant used to thin mucus. It's in popular over-the-counter (OTC) medications, such as Robitussin and Mucinex and multiple combination cough and cold products. It's also used as a muscle relaxant during anesthesia. St. Amand recommends against using most decongestants to get guaifenesin, however, and advocates either Mucinex or pure forms of the drug that can be obtained through certain websites. Because guaifenesin is not a prescription medication, it won't be covered by your insurance.

This protocol is experimental and neither the treatment nor the theory behind it is supported by scientific evidence. To date, only one double-blind, placebo-controlled study has examined it, and researchers found the Guaifenesin Protocol no more effective than a placebo. St. Amand says he's seen great success in his patients and a relatively small group of people with FMS swears by the protocol. Still, many leading FMS experts are unconvinced that this is an effective treatment option.

The information here is not intended to either prove or disprove the Guaifenesin Protocol but is here to help you educate yourself. At the end of this article, you'll find a link to an article arguing against St. Amand's theories and treatment methods.

The Ups and Downs of the Guaifenesin Protocol

On the upside, according to St. Amand, the only side effect of guaifenesin is mild nausea that doesn't last long and only happens rarely. He says it is safe and effective even for children and doesn't have any known drug interactions.

On the downside is that for the treatment to be effective, St. Amand says you have to avoid all sources of salicylates, which he claims keep guaifenesin from having the desired effect on your kidneys.

Salicylates are known to have multiple effects on your body. In painkillers such as aspirin, salicylates block pain, break fevers and reduce inflammation. However, they also make your stomach more acidic, block the formation of protective mucus and increase bleeding. In most people, the liver and kidneys detoxify salicylates, but healthcare providers generally avoid medications containing salicylates in people with kidney disease.

Salicylates are in all kinds of products, including:

  • Anything flavored with mint, mint oil, menthol
  • Oils, extracts, or gels with plant names (except soy, wheat, corn, oats)
  • Many herbal medications
  • Many drugs, including aspirin and topical pain creams
  • Many cosmetics and body-care products

Avoiding all salicylates is difficult and means you'll need to spend a lot of time researching the products you use. On his website, St. Amand makes suggestions for how to avoid salicylates and provides a link to a support group that will help you find appropriate products.

Also, during early phases of the treatment, you'll have cycling flare-ups that St. Amand says are proof that the treatment is beginning to work. Symptoms will likely be more intense than what you're used to for a while, but he says over time the flare-ups will get shorter and less severe until you go into complete remission and no longer have any symptoms at all. The longer you've had FMS, the longer he says it will take you to get to remission.

That means, in order for you to see if this experimental protocol works for you, you'll have to be sicker for a while, and possibly a long while.

St. Amand's Diagnostic Test for Fibromyalgia

St. Amand disregards the standard tender-point test for diagnosing FMS and says he's found a better way to identify the condition and to document physiological improvements. It's called "mapping."

In mapping, practitioners touch you with their finger pads as if they're trying to iron out underlying tissues. They find and document swollen spots in your muscles and connective tissues and note their size and how hard they are. That forms a basis for comparison after you've started the treatment. St. Amand says the most important part of your body for confirming a diagnosis is the left thigh, which he says is affected in 100 percent of adults with FMS. (Again, remember that these are his claims, and they have not been independently verified by research.)

Is The Guaifenesin Protocol Right for You?

Only you can decide whether this protocol is right for you, and you should involve your healthcare provider in the decision process. You may want to find a practitioner familiar with the protocol and possibly have your practitioner consult with him/her.

You'll also want to consider the cost of the treatment, the initial increase in your symptoms and the salicylate restrictions. This is a treatment regimen that takes dedication and determination. And again, there's no scientific evidence that it's effective.

Criticism of the Guaifenesin Protocol

The article entitled The Truths and Myths of the use of Guaifenesin for Fibromyalgia provides a bit of the history behind this protocol, a critique of St. Amand's claims, and an alternate theory as to why some people see results from taking guaifenesin.

3 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Aoki M, Wakuno A, Kushiro A, et al. Evaluation of total intravenous anesthesia with propofol-guaifenesin-medetomidine and alfaxalone-guaifenesin-medetomidine in Thoroughbred horses undergoing castration. J Vet Med Sci. 2017;79(12):2011-2018. doi:10.1292/jvms.16-0658

  2. London M. The truths and myths of the use of Guaifenesin for Fibromyalgia.

  3. Runde TJ, Nappe TM. Salicylates Toxicity. In: StatPearls [Internet].

Additional Reading
  • Fibromyalgia Treatment Center. The Guaifenesin Protocol.

  • Marek, Claudia. Fibromyalgia: The First Year.

By Adrienne Dellwo
Adrienne Dellwo is an experienced journalist who was diagnosed with fibromyalgia and has written extensively on the topic.