Magnesium Chloride: The Basics
What magnesium chloride actually is, where it comes from, why it's the form most commonly used in topical magnesium products, and how it differs from other magnesium compounds.
Magnesium chloride comes up constantly in topical magnesium products, but it's not always clear what it actually is or why it's the form most brands use. Here's a straightforward rundown.
What magnesium chloride is
Magnesium chloride is a naturally occurring salt made of magnesium and chlorine. It's found in seawater and in mineral deposits, and it's highly soluble in water — which is part of why it dissolves so easily into a soak or topical solution. It's sold in a few common forms, including flakes, crystals, and pre-mixed liquid concentrations.
Why it's used topically
Magnesium chloride is the form most commonly used in topical (skin-applied) magnesium products — soaks, sprays, and crèmes — largely because of that solubility and stability in liquid form. It mixes cleanly into water or a carrier liquid without needing complex processing. For more on how the topical route works in general, see Transdermal (Topical) Magnesium 101.
How it compares to other magnesium compounds
Magnesium comes bonded to different compounds depending on the product — citrate, glycinate, oxide, sulfate (Epsom salt), and chloride are among the most common. Most of these other forms are formulated for oral use rather than topical use. Epsom salt (magnesium sulfate) is sometimes confused with magnesium chloride since both are used in soaks, but they're chemically different compounds. If you're weighing topical against oral options generally, see Topical vs. Oral Magnesium: How They Differ.
What the science does and doesn't confirm
Magnesium chloride's role in the body once absorbed is the same as any other magnesium compound — magnesium is magnesium once it's in circulation. What's still an open research question is exactly how much magnesium chloride the skin absorbs when applied topically, and how that compares to oral intake. We're intentionally not putting a number on that here.
This article is general educational information, not medical advice. It is not intended to diagnose, treat, cure, or prevent any disease. Talk with a healthcare professional before starting any new supplement or wellness routine, especially if you have a medical condition or take medication.
Part of our Getting Started guide.
Want to see magnesium chloride in a ready-to-use topical product? Take a look at Mgnify's soak.
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