Magnesium has become a buzzword on deodorant labels, usually with zero explanation of why it's there. Here's the short version: it isn't the thing stopping your odor — and that's exactly the point.
What magnesium actually does
In a well-built natural deodorant, magnesium plays a supporting role. Its contribution is around skin compatibility and helping maintain the conditions the rest of the formula works best in — part of what lets a product stay effective while staying gentle on a high-friction area you treat every single day. What magnesium is not is the primary odor active. That job belongs to zinc.
Why the distinction matters
Plenty of "magnesium deodorants" lean on the word as if magnesium were doing the heavy lifting on odor. It isn't. If a formula's odor control rests on magnesium alone, it's leaning on a supporting player. The actual source-level work — acting on the bacteria and molecules that create smell — comes from the zinc-based BioShield™ system.
Where Zaffré uses it
Magnesium is the variable that distinguishes our two BioShield formulas. MAX is magnesium-enhanced, tuned for heavy sweat and long days. SENSITIVE is magnesium-free and fragrance-free, stripped to the gentlest path to odor control for reactive skin. Same zinc core eliminating odor at the source; magnesium is the dial, not the engine.
So if you're shopping "magnesium deodorant," the better question isn't whether it contains magnesium — it's what's actually stopping the odor underneath.