What is it?
Magnesium is a light, silvery metal and one of the chemical elements. The ingredient name “magnesium” means the metal itself, not magnesium salts such as magnesium sulfate (Epsom salt) or magnesium chloride, which have their own names. The EU lists metallic magnesium as an abrasive, antioxidant, reducing agent and skin-conditioning ingredient. In the body, magnesium is an essential mineral that more than 300 enzymes need to work.
Key information
- The ingredient name Magnesium refers to the metal, which the EU lists as an abrasive, antioxidant, reducing and skin-conditioning ingredient.
- Neither CIR nor the EU's SCCS has assessed the metal as a cosmetic ingredient; CIR has found magnesium compounds such as magnesium sulfate safe as used.
- Suppliers classify fine magnesium powder as a fire hazard that can release hydrogen gas on contact with water, a hazard in handling the raw material.
- A 2017 review concluded that claims that magnesium applied to the skin raises the body's magnesium levels are scientifically unsupported.
More information
Pure magnesium is a reactive metal. It slowly oxidizes in moist air and reacts very slowly with water at room temperature, faster when hot, giving off hydrogen gas. It is a strong reducing agent, meaning it readily gives up electrons, which matches the EU’s listing of it as a “reducing” ingredient. The databases we checked do not say how much magnesium metal is used in cosmetics or in which products, and we found little public information about it.
As a bulk raw material, magnesium powder is a fire hazard. Suppliers’ notifications to the EU chemicals agency commonly classify it as a flammable solid, and some classify it as catching fire on contact with air or releasing flammable gas in contact with water. Direct contact with the powder may irritate the skin, eyes and airways. Neither the Cosmetic Ingredient Review (CIR) nor the EU’s Scientific Committee on Consumer Safety has assessed the metal as a cosmetic ingredient. CIR has reviewed many magnesium compounds and concluded, for example, that magnesium sulfate is safe as used and that magnesium carbonate is safe when formulated to be non-irritating.
Reality check: magnesium is an essential mineral, and you may read that putting it on your skin is a good way to raise your levels. A 2017 review in the journal Nutrients examined “transdermal magnesium” sprays, flakes and salt baths, which use magnesium salts such as magnesium chloride or Epsom salt, and concluded the idea is scientifically unsupported. The skin’s outer layer is a strong barrier to charged magnesium ions. By contrast, the review describes the benefits of magnesium taken by mouth as well documented.
On labels, “magnesium” on its own means the metal; magnesium sulfate, magnesium stearate and magnesium aluminum silicate are different ingredients.
Sources: European Commission CosIng: Magnesium; PubChem: Magnesium; Nutrients (2017): Myth or Reality—Transdermal Magnesium?; Cosmetic Ingredient Review: Quick Reference Table (December 2025)
