Epsom Salts: The Inconvenient Truth

Do you suffer from insomnia, muscle cramps, delayed-onset muscles soreness? If so, then your physical or massage therapist may recommend Epsom salt without even knowing why. In its multitude of benefits, Epsom salts are said to improve sleep, reduce inflammation, improve muscles cramps, wound healing and much more. Epsom comes from the name of the English town that the mineral compound, magnesium sulfate, was first discovered. It was extracted by boiling water from a bitter saline spring that people would soak in for great health benefits. The medicinal properties are said to be established by a chemist Nehemiah Grew in 1695, who acquired a royal patent for exclusive manufacturing rights. Today, Epsom salts are a main ingredient in most bath salts and soaks and can be found at almost any pharmacy or bath specialty stores. Before you go take a soak, what does the science say?

Figure one is a molecular model of magnesium sulfate

Well the inconvenient truth is that there is little to no research on the effects of bathing in an Epsom salt bath. There are endless blogs out there with endless claims about the health benefits of Epsom with nothing to back it up. For example, there’s a claim that it’s good for people who are magnesium deficient, but there’s no evidence the magnesium is absorbed through the skin. After searching for articles for magnesium sulfate, bath salts, Epsom salts, I have found not a single article that even investigates Epsom salt baths. The closest thing I found was a patent for methods of different bath soaks, which just boil down to saying put salt in warm water and soak for 15 minutes. Other bloggers seem to have the same problem when trying to find the proof, (in the references below is a link to another similar article.)
I did however find articles about other medical uses for magnesium sulfate. In the study from Maternal-Fetal Medicine Units Network, they wanted to test if magnesium sulfate could help prevent cerebral palsy in preterm babies. 2241 women at imminent risk for delivery between 24 and 31 weeks of gestation, were randomized into experimental (magnesium sulfate) and placebo (control) groups. Each group receive magnesium sulfate, administered intravenously as a 6-g bolus followed by a constant infusion of 2 g per hour, or matching placebo. After a follow up analysis, the rate of the primary outcome was not significantly different in the magnesium sulfate group and the placebo group. However, in a secondary analysis, moderate or severe cerebral palsy occurred significantly less frequently in the magnesium sulfate group. The risk of death did not differ significantly between the groups.

In my references, there is also another article about using magnesium sulfate to treat polymorphic ventricular tachycardia. Long story short is there is no evidence to support the claims people make about Epsom salt baths. I’m surprised there isn’t any actual science considering a folk remedy that been around for hundreds of years. We can only go by What other people say. I can see some merit to the muscle relaxation benefit because magnesium sulfate can be used as a laxative and magnesium chloride is a common ingredient in rescue inhalers, in both cases it relaxes muscles. But again, there is no research on it. The best thing to do is try it and see if it works for you.


Questions to consider

Do you use Epsom salt? If so, Why?

Do you feel it helps?

Any thoughts why there is no research?



Dwight J. Rouse, M.D., Deborah G. Hirtz, M.D., for the Eunice Kennedy Shriver NICHD Maternal–Fetal Medicine Units Network*

N Engl J Med 2008; 359:895-905 August 28, 2008 DOI: 10.1056/NEJMoa0801187


Treatment of torsade de pointes with magnesium sulfate.

D Tzivoni, S Banai, C Schuger, J Benhorin, A Keren, S Gottlieb and S Stern

Circulation. 1988;77:392-397, originally published February 1, 1988






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8 thoughts on “Epsom Salts: The Inconvenient Truth

  1. I had never heard about Epsom salts until a track coach recommended it to me. I tried this out, but I did not feel like it had much of an effect. (I am also too impatient to actually sit in a bath for longer than 5 minutes so that might have contributed to my decision to not continue using it). The fact that there is not much research done on Epsom salts might also be because it is not a very popular item? I was really curious when I used it though to whether the magnesium can actually be absorbed through your skin, like you mentioned in the beginning.

  2. I agree with you on the fact that Epsom salt is most likely considered an old folk remedy and therefore people haven’t done extensive research into it. Furthermore I’ve heard of other remedies, such as melatonin and dietary changes, that supposedly have the same benefits of reducing inflammation. Therefore, people might consider it more convenient to eat their remedy than take a bath in it.

  3. When I was abroad in Dominica we went to a “natural spa” where the spring water was “rich in minerals” and basically claimed to have the same benefits of muscle relaxation as Epsom salts. I was curious whether there was any actual science to sport the claims and after reading this I am guessing there isn’t much. I felt that the benefit of the bath was really the warm water and mental break rather than any mineral benefit for my muscles.

  4. This was an interesting post to read. Back when I ran in high school, my one coach would always say “Oh, you’re sore? Try some epsom salts.” She always recommended epsom salt baths. But, anytime I used epsom salts, I never noticed any real difference. Maybe I was expecting immediate, total relief of muscle pain or something. But even so, I really didn’t feel like epsom salts even helped a little bit. So, this was an interesting post to read. Hopefully, someone does some research into epsom salts in the future; but for now, I think I’m going to stick to stretching for muscle soreness!

    • That was a really small study, 19 people. It showed an increase of magnesium in blood and urine. That doesn’t mean that an epson salt bath helps muscle or joint pain or reduces swelling. A double blind study with hundreds of people would be a good start. Also, I would be more likely to believe a study that had been peer reviewed/ published and this one had not.

  5. Epsom salt bath work for me 100% the longer you soak and the hotter the water the more effective dont knock it till you try it and why wouldn’t magnesium absorb through your skin every thing absorbs through your skin if you expose it to your skin long enough I soak daily in at least 1lb per bath I’m talking you need enough to make you float and you need to stay in there for an hour but it totally works give it a try don’t be a hater

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