What Is Epsom Salt?
What It Is
Epsom salt is magnesium sulfate (MgSO4·7H2O), a mineral compound with no relation to table salt beyond the shared name. It contains no sodium chloride and is named after Epsom in Surrey, England, where it was historically crystallised from local spring water. It is widely used as the mineral base of bath-salt formulations.
What It Does
Magnesium sulfate dissolves readily in warm water and contributes to the dissolved-mineral environment of a bath. The source material describes its role in skin feel and bathing experience, while also distinguishing those effects from claims about systemic magnesium replacement.
How It Functions in a Formulation
In a bath formulation, Epsom salt dissolves into magnesium and sulfate ions. Its solubility makes it practical for mineral bath products. The source also discusses concentration, water temperature, water hardness and its use in bath, foot-soak and bucket-bath formulations.
Safety and Tolerance
Tolerance depends on concentration, water temperature, duration and individual skin condition. The source identifies kidney disease, blood-pressure medication, broken skin and ingestion as situations requiring particular caution. Bath-grade material should not be treated as an oral supplement.
What the Source Supports
The source supports magnesium sulfate as the chemical identity and a widely used mineral-bath ingredient. It also discusses evidence for skin and bathing effects and explicitly treats transdermal magnesium supplementation as contested rather than established. Detoxification and medical-treatment claims are not supported by the source.