Epsom Salts for Fibromyalgia and Chronic Fatigue Syndrome

Do Epsom-salt baths ease the pains of fibromyalgia and chronic fatigue syndrome? They're a common self-treatment, but do Epsom salts really do anything? And if so, how?

Epsom salts aren't really "salt." They're crystals of magnesium sulfate and they've been used as a home remedy for hundreds of years.

Many people with these conditions say that Epsom-salt soaks are more helpful and more effective than a hot bath by itself. However, that's not something we can prove or quantitatively measure on our own. It's not hard to find skeptics who believe any improvement is due to the placebo effect.

At the same time, you can find claims online about all kinds of things that Epsom salts can supposedly do. Some people say that they ease all types of pain as well as speed healing. You can also read that topical magnesium sulfate (applied to and absorbed through the skin) is more effective than taking oral magnesium supplements.

If you start digging into it, though, there's not much science behind these claims. In fact, Epsom salts and other forms of topical magnesium sulfate have barely been researched at all.

What Do We Know?

Ingested magnesium, such as from food or supplements, is important for several bodily functions. We know that it is involved with:

• Your body's energy production in the form of adenosine triphosphate
• Formation of cells
• Maintenance of muscles, bones, and nerves

Some people claim that magnesium supplements reduce the specific types of pain and tenderness that characterize fibromyalgia and are part of some cases of chronic fatigue syndrome.

On the flip side, magnesium can also be really hard on the digestive system. It can cause nausea, persistent diarrhea, bloating, and cramping, and many of us can't tolerate it as a supplement.

Lots of Questions

All of those benefits are linked to magnesium in your diet or taken as a supplement. When you make the jump from ingested to topical use, though, a couple of questions arise:

1. Is magnesium absorbed through the skin, and if so, does enough get through to make a difference?
2. Does it have the same benefits as ingested magnesium?

We do have a limited amount of evidence about the first question. Most things are not absorbed through the skin, which is waterproof. However, a small (unpublished) 2006 study by Rosemary Waring suggested that a 12-minute Epsom salt baths did raise the blood and urine levels of both magnesium and sulfate by a small amount.

Is it enough to make a difference? That depends on a lot of factors, and right now we just can't answer that question definitively. Because it does get into the bloodstream, there's no reason to believe it works differently than ingested magnesium. And absorbing it this way may bypass the unpleasant digestive side effects.

Unsupported Claims

Some online claims about Epsom salts' benefits are completely unsupported or even contradicted by science.

A common one is that it "detoxes" your muscles through "osmosis." Remember us mentioning that skin is waterproof? That automatically rules out osmosis, because that process by definition means movement of water through a membrane. Particles dissolved in water may well be able to pass through skin, but water does not.

And detoxification? Your body already takes care of that. The term "detox" has become a buzzword that few people really understand. The long and short of it is that your body has perfectly good systems for eliminating toxins. So, unless you have liver or kidney disease, you don't need to worry about detoxing. At best, claims regarding detox are unsupported scientifically. At worst, they could be dangerous.

So ... Where Do We Stand?

Those of us with fibromyalgia and chronic fatigue syndrome know all too well that science still has a lot to learn. Some of the treatments people find to be most effective are unproven, even uninvestigated, by researchers, while for some, the well-researched treatments are utter failures. Still, when unproven claims abound, it pays to be skeptical.

Because Epsom ​salts have been popular for a long time, we do at least know they're not dangerous. However, if you expect miracles based on unfounded claims, you're likely to be disappointed. If Epsom salt baths work for you, great! Just don't expect dramatic improvements or a cure.

And a long, hot bath is usually good for us, so soak away!