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Magnesium Sulfate

What Magnesium Sulfate is & what it does

Epsom salt, a mineral used to thicken some formulas and to add minerals. It can also help stabilize water-in-oil emulsions.

What is Magnesium Sulfate and what does it do in sunscreen?

Magnesium Sulfate is Epsom salt, a simple mineral salt used in formulas mainly to adjust texture. It helps thicken some products and is especially useful for stabilizing water-in-oil emulsions, the type where water droplets are suspended in an oily base. It works on the structure of the formula rather than on the skin directly.

Is Magnesium Sulfate safe?

Yes. Magnesium Sulfate is the same mineral salt found in Epsom salt bath products and is well tolerated on skin at the small amounts used in cosmetics. It is used to fine-tune texture and stability, not to penetrate or treat the skin. For most people it raises no concern in a sunscreen.

Is Magnesium Sulfate a thickener?

Yes, that is one of its main jobs here. Magnesium Sulfate helps thicken certain formulas and stabilizes water-in-oil emulsions so the product stays smooth and does not separate. It is a texture and stability helper rather than an active ingredient or a sunscreen filter.

Does Magnesium Sulfate clog pores?

Generally no. It is a water-soluble mineral salt, not an oil or wax, so it is not the kind of ingredient associated with clogged pores. It is used in small amounts to manage texture, which makes it an unlikely culprit if your skin is breaking out.

What else is Magnesium Sulfate called?

Its most familiar name is Epsom salt, the bath-soak mineral, though on a cosmetic label it appears as Magnesium Sulfate. Chemically it is just magnesium and sulfate combined as a salt. In an ingredient list it usually sits low down among the texture and stability helpers.

Sunscreens with Magnesium Sulfate

We rate 731 sunscreens that contain it, showing the top 10 by overall score:

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