Epsom salt is a mineral compound of magnesium and sulfate that you can use in baths, foot soaks, skin scrubs, garden care, and even as an occasional laxative. Despite the name, it’s not related to table salt. The most common use is dissolving it in warm water for a soak, but the method and amount vary depending on what you’re trying to accomplish.
Full Body Bath
The standard ratio is about 2 cups of Epsom salt dissolved in a standard bathtub of warm water. Run the water first, then pour the salt under the faucet so it dissolves completely. Water temperature should be comfortably warm but not hot, typically around 92 to 100°F. Soak for 12 to 20 minutes.
Many people use Epsom salt baths for sore muscles after exercise or for general relaxation. Warm baths on their own lower cortisol, the body’s main stress hormone, and magnesium may contribute to that calming effect. Whether your skin actually absorbs a meaningful amount of magnesium during a bath is still debated. Research indicates it’s difficult for magnesium to penetrate the skin in significant quantities, though some studies suggest hair follicles may serve as a pathway. Regardless of the magnesium question, the warm water itself reliably eases muscle tension, improves circulation, and helps with relaxation before sleep.
You can take Epsom salt baths two to three times per week. Rinse off afterward if your skin feels dry, since the salt can be mildly dehydrating to the skin’s surface.
Foot Soaks
For a foot soak, add half a cup of Epsom salt to a gallon of lukewarm water in a basin or foot tub. Soak for 30 to 60 minutes twice a week for general soreness or tired feet. If you’re dealing with a toenail fungal issue, the recommended approach is soaking twice daily for about 20 minutes per session. Epsom salt won’t cure a fungal infection on its own, but the soak can soften the nail and surrounding skin, making topical treatments more effective.
Foot soaks also help with corns and calluses. The salt softens hardened skin, making it easier to gently file down afterward. Dry your feet thoroughly when you’re done, especially between the toes.
Skin Scrub
Epsom salt works as a physical exfoliant when mixed with oil. Combine 1 cup of Epsom salt with 3 tablespoons of a carrier oil like coconut, olive, or sweet almond oil. Stir until evenly combined. You can add a few drops of essential oil for scent if you like.
Apply the scrub to damp skin in gentle circular motions, focusing on rough areas like elbows, knees, and heels. Avoid your face, where the crystals are too coarse and can cause micro-tears or irritation. Rinse thoroughly and follow with moisturizer. If you make a batch to keep, store it in the refrigerator and use it within two weeks.
Garden Applications
Epsom salt supplies magnesium to plants, which is essential for photosynthesis and nutrient absorption. It’s most commonly used on tomatoes, peppers, and roses, all of which are heavy magnesium feeders.
For tomatoes and peppers, the general guideline is 1 tablespoon per foot of plant height, applied every two weeks. You can dissolve it in water and pour it at the base of the plant, or mix it into a spray bottle for foliar feeding. For roses, the same ratio applies (1 tablespoon per foot of height, every two weeks), with an additional half cup scratched into the soil at the base of the plant to encourage new cane growth. When planting new rose bushes, add a tablespoon to each hole, and you can soak bare-root bushes in 1 cup of Epsom salt per gallon of water before planting to help roots recover from transplant stress.
One important caveat from Washington State University: applying Epsom salt to plants that aren’t actually magnesium deficient can do more harm than good, potentially injuring plants and contaminating soil. Signs of magnesium deficiency include yellowing between the veins of older leaves while the veins themselves stay green. If your plants look healthy, skip the Epsom salt. A soil test is the most reliable way to know whether your garden actually needs it.
Occasional Laxative Use
Epsom salt is approved for oral use as a saline laxative. The standard adult dose is 2 to 6 level teaspoons of the powder dissolved in 8 ounces of water, taken as a single dose or split into two doses separated by at least four hours. Do not exceed two doses per day. It tastes bitter, so some people add lemon juice to make it more palatable.
This is strictly for occasional constipation, not regular use. The osmotic effect draws water into your intestines, which softens stool and stimulates movement. Only use Epsom salt labeled “USP grade” for oral consumption, as bath-grade products may contain additives or fragrances that aren’t safe to ingest.
Who Should Be Cautious
Oral Epsom salt is not safe for everyone. People with kidney disease should not consume it at all, because the kidneys are responsible for filtering excess magnesium and impaired kidneys can allow dangerous buildup. People with heart disease and those who are pregnant should also avoid oral use. Children under 12 should not take it without medical guidance.
For bath use, the risks are much lower since skin absorption is limited. Still, if you have open wounds, severe skin conditions, or burns, the salt will sting and may irritate damaged tissue. People with diabetes should check water temperature carefully, since nerve damage in the feet can make it hard to gauge heat, increasing the risk of burns during foot soaks.
Choosing and Storing Epsom Salt
Epsom salt is sold at pharmacies, grocery stores, and garden centers. For baths, foot soaks, and scrubs, plain unscented varieties are the most versatile. Scented versions with added essential oils work fine for soaking but shouldn’t be used in the garden or taken orally. For garden use, any plain agricultural or pharmacy-grade Epsom salt will work.
Store it in a sealed container in a cool, dry place. Epsom salt absorbs moisture from the air and can clump over time. Clumping doesn’t affect its effectiveness, just dissolve the clumps in warm water as you normally would.