Epsom salt, also known as magnesium sulfate, is a dissolvable granule form of the mineral magnesium. Some magnesium can be absorbed through the skin when soaking in a bath treated with Epsom salt, and large amounts of magnesium can be absorbed through the digestive tract when Epsom salt is taken orally as a laxative. It's important to take caution when using Epsom salt orally, as approximately 3.5 grams of magnesium -- or about 100 times the recommended daily intake -- is in 1 tablespoon of Epsom salt.
Absorption of Magnesium Sulfate Through the Skin
According to the Epsom Salt Council, a certain amount of magnesium in Epsom salt is readily absorbed through the skin. Supporting this statement is a 2004 study conducted by the School of Biosciences at the University of Birmingham, which measured the magnesium status of participants before and after taking baths containing dissolved Epsom salt. From the results, researchers concluded that prolonged soaking in an Epsom salt bath raises magnesium levels without any adverse effects. The ideal concentration for using Epsom salt baths to raise magnesium status, according to the study, is approximately 500 grams, or 2 cups, of Epsom salt dissolved in 15 gallons of water -- the amount that can fit in a standard-sized bathtub. Ideal amount of time spent soaking is 12 minutes, two to three times per week.
Advantages of Epsom Salt Baths
While magnesium supplements may be taken orally, other foods, drugs and certain medical conditions may interfere with their effectiveness, according to the Epsom Salt Council. Epsom salt baths may also be an effective, yet-gentle, way to raise magnesium levels without taking supplements. Correcting a magnesium deficiency using Epsom salt baths may provide relief from the following symptoms of magnesium deficiency: agitation and anxiety, insomnia, irritability, nausea and vomiting, abnormal heart rhythms and muscle spasms. Magnesium is also considered a natural stress reliever.
Taking Epsom Salt Orally
Magnesium may also be absorbed from Epsom salt when it is taken orally. As large amounts of magnesium have a laxative effect, Epsom salt is commonly taken orally to relieve occasional constipation. Compared to stimulant and lubricating laxatives, Epsom salt is a safer alternative, according to Professor David Lubowski, Associate Professor of Surgery at Sydney's St. George Hospital. It's important, however, to use Epsom salt only as directed on the package, as taking excessive amounts of Epsom salt orally can cause a magnesium overdose, especially if you have kidney problems. According to Drugs.com, it's important to consult your doctor before taking Epsom salt as a laxative to make sure you don't have any kidney problems.
While an Epsom salt bath is generally a safe and gentle way to raise magnesium levels, it is good to check with your doctor before using it to treat any medical conditions or using it while pregnant. Epsom salt baths may also be somewhat drying to the skin. Unless directed otherwise by a doctor, you should not take Epsom salt orally if you have constipation that is accompanied by stomach pain, nausea or vomiting. If you suspect that you or your child have overdosed on magnesium by ingesting too much Epsom salt, seek immediate medical attention. Magnesium overdose may cause flushing, nausea, vomiting, low blood pressure, slow heartbeat, drowsiness, coma and even death.