Epsom Salt

What Is Epsom Salt?

Despite its name, Epsom salt is not actually salt in the culinary sense. It is magnesium sulfate heptahydrate (MgSO4·7H2O), a completely different chemical compound from the sodium chloride (NaCl) found in table salt, sea salt, and other culinary salts. Epsom salt dissolves in water and looks similar to regular salt crystals, but it has a distinctly bitter taste that makes it unsuitable for food. Its primary uses are therapeutic (bath soaks), horticultural (plant fertilizer), and occasionally medical (saline laxative).

Epsom Salt Bath Benefits

Epsom salt baths have been used for centuries to soothe sore muscles, reduce inflammation, and promote relaxation. To prepare an Epsom salt bath, dissolve 2 cups in a standard bathtub of warm water and soak for 15-20 minutes. The theory is that magnesium absorbs through the skin, helping to relax muscles and reduce cortisol levels. While peer-reviewed evidence is limited, a 2004 study from the University of Birmingham showed that blood magnesium levels did increase after Epsom salt baths. Athletes, people with arthritis, and those with fibromyalgia commonly report benefits.

Epsom Salt in the Garden

Gardeners have used Epsom salt as a plant supplement for decades. Magnesium is a central component of chlorophyll, the molecule that allows plants to photosynthesize. Sulfur helps with protein production and enzyme activity. Plants that benefit most include tomatoes (prevents blossom end rot when caused by magnesium deficiency), peppers, roses, and leafy greens. Apply by dissolving 1-2 tablespoons per gallon of water and using as a foliar spray or soil drench monthly during the growing season. Do not overuse, as excess magnesium can interfere with calcium uptake.

Mineral Profile

Best Uses for Epsom Salt

Quick Facts