Who put the Epsom in Epsom Salt?

After two days of work digging a trench on our property, my husband Charlie’s feet ached. He called out from our bathroom, “I’m going to soak my feet. Where is the Epsom Salt?”

Epsom Salt is another name for magnesium sulfate. In 1675, Dr. Nehemiah Grew obtained magnesium sulfate crystals from evaporating the mineral water of Epsom, England. The mineral water from the Seiditz Spring in Germany was nearly identical to the water from Epsom and also used as a source of magnesium. At first, Seiditz Salt and Epsom Salt were used interchangeably to refer to magnesium sulfate. Today, Epsom Salt is the only name that remains.

In Colonial America, magnesium sulfate was produced from rock veins near Baltimore and southern Pennsylvania. By the late 1880s, salt mines were replaced by evaporating seawater. After extracting sodium chloride (table salt) from seawater, the brine left over contains nearly pure magnesium sulfate, AKA Epsom Salt.

Often packaged in quart-sized milk cartons, Epsom Salt or magnesium sulfate is a white, odorless powder that tastes salty and bitter. It is widely used today, externally as a solution for soaking sore feet and muscles and internally to relieve constipation.

In the 1800s, ensuring your bowels moved frequently was considered essential to your health. Bowel movements were widely believed to remove toxins from the body, and the way to stay healthy was to prevent toxins from building up. That meant making sure you and your loved ones emptied their bowels regularly.

To support this belief, many patent medicines, called cathartics, contained compounds that stimulate bowel movements. The least intense of these were called laxatives. The next powerful cathartics were called “purgatives," and the most potent cathartic compounds were  “drastics "Epsom Salt is a salt-based laxative and can be either a laxative or a purgative, depending on the dose used.

Other magnesium products with stimulant action on your bowels include magnesium hydroxide and citrate. Magnesium hydroxide is less potent than magnesium sulfate, with its milky white color inspiring the name “milk of magnesia." Some milky white liquid antacids, like Maalox® and Mylanta®, contain magnesium hydroxide.

Magnesium citrate is sold as a clear solution containing sodium bicarbonate and citric acid to make it carbonated. This liquid laxative is available in a glass bottle as “citrate of magnesia."

When you add magnesium sulfate (Epsom Salt ) crystals to water and drink it, it pulls extra water into your intestines, making your stool more liquid. This watery stool moves more quickly through your intestine, colon, and rectum. The more concentrated the solution of magnesium sulfate, the more powerful its laxative effect.

Soaking in a saline solution like table salt or Epsom Salt can help shrink tissues by pulling fluid out of them. This can help decrease swelling and pain. Soaking in warm table salt or Epsom Salts also softens and shrinks the skin around embedded foreign bodies like splinters and insect stingers. This often makes them much easier to remove.

Like my husband, you can add Epsom Salts to foot soaks or bath water for a therapeutic bath to relieve aches. The magnesium in Epsom Salt can be absorbed through the skin, helping to alleviate muscle cramps.

Epsom salt is safe when used externally for soaking, but be careful about taking it by mouth, as the amount of magnesium absorbed into your body can be unpredictable.

One woman died from gargling with Epsom Salts due to absorbing excessive magnesium, causing her heart to stop. Another woman almost died from heart block after using an enema made from 3 tablespoons of Epsom Salts dissolved in warm water. Two children went into cardiac arrest, and one died after consuming several doses of a mega-mineral supplement containing a large amount of magnesium.

If you use Milk of Magnesia or magnesium citrate for constipation, DO NOT exceed the doses recommended on the label.

Here are 3 Key Facts About Epsom Salt:

1.         Magnesium is absorbed through the skin.

Soaking in warm water with magnesium salt has a calming effect on muscles. This can help relieve aching feet, restless legs, or nocturnal muscle cramps.

2.         Salt soaks can prevent infection.

Soaking splinters in hot salt water (either Epsom Salt or table salt) for at least 20 minutes, 1-2 times daily, can discourage infection. Salt soaks help keep the top of the skin open. This makes the splinter easier to extract while preventing the development of an abscess.

3.         Never exceed recommended doses.

Magnesium can be unpredictable when taken internally. Taking too much can depress the action of your heart.

Dr. Louise Achey, Doctor of Pharmacy, is a 43-year veteran of pharmacology and author of Why Dogs Can’t Eat Chocolate: How Medicines Work and How YOU Can Take Them Safely. Get clear answers to your medication questions at her website and blog, TheMedicationInsider.com.

Ó2022 Louise Achey