Bath salts and soaks

Bath salts, magnesium flakes, Dead Sea salt, bath teas and bath bombs are different things with different ingredients. This guide explains what each one is, how to use it, and what the evidence does and does not support, drawing on Cleveland Clinic and the National Institutes of Health.

Epsom salt

Epsom salt is magnesium sulfate, a mineral compound, not a table salt; Cleveland Clinic notes it tastes bitter and is not meant to be eaten. A typical bath uses about 300 grams, roughly a cup and a quarter, dissolved in warm water for a soak of around 15 minutes. Cleveland Clinic also points out that there are no definitive studies showing magnesium is absorbed through the skin in meaningful amounts, so treat an Epsom bath as a relaxing ritual rather than a treatment. It advises against soaking with severe skin inflammation, skin infections, open wounds or severe burns.

Magnesium chloride flakes

Magnesium flakes are magnesium chloride, a different magnesium compound from Epsom salt. They dissolve quickly and are often sold as “magnesium bath flakes.” The same note applies: enjoyable in a bath, but not a proven way to raise magnesium levels.

Dead Sea salt

Salt harvested from the Dead Sea is unusual because it is dominated by magnesium, potassium and calcium chlorides rather than sodium chloride. It is used for its mineral content and texture in soaks and scrubs.

Bath teas

A bath tea is a muslin or cotton bag of dried herbs, flowers and salts that steeps in the tub as it fills, like a giant tea bag. It keeps the botanicals out of the drain; discard the bag after use. Slow North makes herbal bath teas in Austin.

Bath bombs

A bath bomb fizzes from a mix of baking soda and citric acid, and usually adds fragrance, color, and oils or butters. Cleveland Clinic dermatologist Alok Vij notes that bombs may contain synthetic or essential-oil fragrance, dyes and glitter, that no bath bomb is entirely free of irritation risk for sensitive skin, and suggests limiting the bath to 10 to 15 minutes and rinsing off afterwards. Oils and butters can also make the tub slippery, so step out carefully.

Color and fragrance

The FDA requires color additives in cosmetics to be approved, and allows “fragrance” to be listed as a single ingredient. Each product page shows the maker’s own ingredient list.

Choosing from our range

The bath salts and soaks collection includes Slow North’s bath salts, bath bombs and bath teas, Spice Beauty’s magnesium salt soak and more. For after the bath, see body butters and body oils.