Magnesium in Hot Springs
Magnesium is dissolved into thermal waters from dolomite, basalt, and other magnesium-bearing minerals deep in the earth's crust. Hot spring concentrations typically range from 1 mg/L to over 200 mg/L. Springs emerging from volcanic or metamorphic terrains tend to have the highest magnesium content.
Why Magnesium Is Prized in Soaking
Magnesium is perhaps the mineral most associated with the relaxing effects of hot spring bathing. It plays essential roles in over 300 enzymatic reactions in the human body, including muscle relaxation, nerve function, and stress hormone regulation. Many people are mildly deficient in magnesium, which has led to significant interest in transdermal absorption through bathing.
A pilot study published in PLoS ONE demonstrated that soaking in magnesium-rich water (Epsom salt baths) increased serum magnesium levels, supporting the concept of transdermal absorption. Hot springs with naturally high magnesium concentrations may offer similar benefits in a more enjoyable setting.
Traditional Uses
Japanese onsen therapy has long valued magnesium-rich springs for their calming effects and use in treating muscle tension, insomnia, and stress-related conditions. Hungarian thermal baths, many of which are naturally rich in magnesium, have been studied for their positive effects on chronic lower back pain and fibromyalgia symptoms.
Disclaimer: The information on this page is for educational purposes only and does not constitute medical advice. Always consult a healthcare provider before using hot springs for therapeutic purposes.