What it is
Magnesium chloride is a water-soluble salt that can influence the viscosity and texture of water-based formulas and contribute a conditioning effect. In sunscreens it generally appears as a minor functional additive rather than an active. It is typically used at low concentrations.
Safety & warnings
Magnesium chloride is generally well tolerated in cosmetic use at typical concentrations. As a salt it could feel slightly drying at high levels, but at the amounts used in finished formulas it is not regarded as a notable irritant or sensitizer.
Origin & sourcing
Mineral salt; obtained from natural brine and seawater sources or produced synthetically.
Questions everyone asks
What does magnesium chloride do in a sunscreen?
It is a mineral salt used mainly to adjust texture and viscosity and to provide a conditioning effect.
Is magnesium chloride a natural ingredient?
It can be sourced from seawater and natural brine, though it is also produced synthetically.