What Are Epsom Salts?

A Natural Remedy for Sore Muscles, Constipation, and More

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Epsom salts, also called magnesium sulfate, are a naturally occurring chemical compound thought to help with certain conditions. Those who use Epsom salts do so for a variety of reasons, such as reducing stress, easing muscle soreness, and taming skin irritation.

Epsom salts on a table with a wooden scoop.
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This article explains what Epsom salts are and how they work. It also covers how to use Epsom salts, as well as potential benefits and side effects.

What Are Epsom Salts?

Epsom salts are a type of mineral salt found in nature. Specifically, this type of salt is a compound of magnesium and sulfate.

Epsom salts look very much like coarse salt you might find in a kitchen. However, they are not meant for cooking with and taste very bitter.

Rather, they can be dissolved in the bath or applied to the skin. If unscented, they can also be dissolved in drinking water.

It's the magnesium that is thought to bring about purported health and beauty benefits. This mineral helps with many processes in the body, including muscle functioning, bone growth, and the processing of energy.

Epsom salts can be purchased at grocery stores, health stores, and pharmacies.

What Is Epsom?

Epsom is not a what but a where. Epsom salts were named after a spring in Surrey, England where they was first found.

How Epsom Salts Work

Dissolving Epsom salts in bathwater allows them to break down into magnesium and sulfate. It's said that soaking in a tub filled with Epsom salts allows these components to get absorbed into the skin so your body can use them.

However, whether or not the amount that is absorbed by the skin is sufficient enough to have an effect on your health is not well-supported.

Multiple studies have shown that little to no magnesium is absorbed from an Epsom salt bath. In fact, magnesium has a difficult time getting through all the layers of the skin. Similar results were also noted when magnesium sulfate skin creams were used.

Magnesium sulfate works effectively when taken by mouth as a laxative. It works by taking water from the rest of your body and bringing it into your digestive tract. This makes having a bowel movement easier.


Epsom salts are thought to help with a variety of conditions, though there is not a lot of research to support this. Since the risks of uses are relatively minimal for most, some people—including some healthcare providers—view the potential pros as outweighing the any cons.

Muscle Aches, Pain, and Injuries

Your healthcare provider may recommend Epsom salts baths as an alternative treatment for certain conditions.

Besides being relaxing, Epsom salts soaks are often used to:

Skin and Hair Health

Epsom salts may be used to help remove dead skin from the face, body, and scalp. It can also be used as a hair mask to increase hair volume.

Other uses may include:

  • Soothe itchiness from poison ivy and mosquito bites
  • Soften skin affected by psoriasis, a disorder that causes scaly patches of skin
  • Cleanse and soothe sores from genital herpes, a sexually transmitted infection

Constipation Relief

Epsom salts taken as a laxative are effective at relieving constipation. Many individuals are able to have a bowel movement within six hours.

Pure Epsom salts that do not contain fragrance or other additives can be taken by mouth by adults and children 12 and older.

How to Use

Epsom salts may be used on the skin or (if unscented) taken by mouth.

Always follow the product instructions when using Epsom salts. The amount of product you need will vary depending on which form and brand of Epsom salts you are using.

Keep in mind that there are different grades of Epsom salts: USP and agricultural. Products labeled with "USP" meet the standards of the United States Pharmacopeia, a third party that monitors for purity, and are the only ones that should be used.

For Muscle Aches, Pain, and Injuries

To make an Epsom salts bath to soak in for muscle aches, pain, and minor injuries:

  • Dissolve one to two cups of Epsom salts in running warm water
  • Soak for 10 to 15 minutes

Be sure to follow the package instructions for more details on how much product to use, as well as how often you can take an Epsom salts bath.

You may also want to check the package for information on specific tub use. In some cases, Epsom salts can't be used in tubs that have jets.

For Improved Skin and Hair

There isn't research that says Epsom salts are effective when used cosmetically. However, some use Epsom salts to remove dead skin or add volume to hair.

To use it on skin, combine 1/2 teaspoon of the salts with liquid body wash. Apply the mixture to the skin in a circular motion, then rinse the skin clean.

If using it on your hair, add equal parts hair conditioner and Epsom salts. Mix well. Leave it on for 20 minutes and then rinse your hair.

It's also important to note that some individuals may experience skin irritation or an allergic reaction. Always test a small amount of product before applying it in larger amounts. Reach out to your healthcare provider if you experience a severe reaction.

To Help With Constipation

It's best to speak with your doctor before using Epsom salts as a laxative, especially if you have another medical condition. Keep in mind that serious side effects and drug interactions are possible.

If you get the green light, be sure to purchase plain, unscented Epsom salts. Many have added ingredients intended for soaking, not ingestion.

Always follow the package instructions when using magnesium sulfate as a laxative.

In general:

  • Dissolve one dose, according to the package instructions, in eight ounces of water
  • Stir to help it further dissolve
  • Drink it all

This should result in a bowel movement within a half hour to six hours. If not, let your healthcare provider know.


Epsom salts should be stored in an air-tight container and kept dry. In laxative form, they should be stored in a cool, dry place that is out of reach of children and pets.


Epsom salts should be used with some caution. It's always best to speak with your healthcare provider before using this product.

Dry Skin

When used topically, they can dry out the skin. This can be problematic in cold weather and for people with sensitive or naturally dry skin. Some individuals may also experience an allergic reaction.

Start with just a little salt (1/4 cup) in the bath and gradually increase as tolerated. Watch your skin closely for dryness or an allergic reaction. Be sure to moisturize the skin after a soak.

Stomach Issues and Discomfort

Taken orally, Epsom salts can cause diarrhea and stomach discomfort. Talk to your healthcare provider before using Epsom salts as a laxative if you have a kidney condition, stomach pain, nausea, or vomiting.

You should also speak to your healthcare provider if you've had a sudden change in your bowel habits. Epsom salts should not be used by those who are on a low-magnesium diet.


Epsom salts are a natural compound made up of magnesium and sulfate. They are commonly dissolved in the bath, applied topically, or taken as a laxative.

While research shows that Epsom salts don't absorb well into the skin, individuals still use them to help with a variety of conditions.

While helpful for some, Epsom salts can lead to side effects. It's best to speak with your doctor before trying Epsom salts.

Frequently Asked Questions

  • Are Epsom salts and bath salts the same?

    No. Epsom salts only contain magnesium and sulfate. However, bath salts may contain other ingredients like added fragrance or coloring.

  • Can Epsom salts help with sore muscles?

    There is no evidence that supports that Epsom salts help significantly with sore muscles. But, taking a warm, relaxing bath may help sore muscles.

  • Should I rinse after an Epsom salts bath?

    Rinsing after an Epsom salts bath can help remove the salt residue from your skin which may be visible, or cause skin dryness.

  • How long should I soak in an Epsom salts bath?

    Soak for 10 to 15 minutes.

7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Mark Stibich, PhD
Mark Stibich, PhD, FIDSA, is a behavior change expert with experience helping individuals make lasting lifestyle improvements.