How Zinc Deodorant Works
Why Sweat Smells
Fresh sweat is nearly odorless. The smell is a by-product. Bacteria living on your skin, mainly Staphylococcus and Corynebacterium, feed on the fats and proteins in sweat and release volatile short-chain fatty acids. Those are the compounds you can actually smell.
Your skin's surface is naturally acidic, around pH 4.7 across the body and closer to 5.5 or 6.5 in the underarm, where sweat output runs higher. That acidity is part of what keeps those bacteria in check.
The Zinc at the Center
Zinc chloride hydroxide is the active in Core, Max, and Sensitive. It's a fine crystalline mineral powder, chemically identical to simonkolleite, and it doesn't dissolve in water, which is why it stays where you put it.
It works by adsorption. It captures and holds the odor molecules bacteria release, with a secondary effect of limiting bacterial growth. It doesn't mask anything and it doesn't stop you sweating.
What sits alongside it
Core and Max pair the zinc with magnesium hydroxide, a mineral that barely dissolves in water and neutralizes the acidic compounds behind the smell. Because it only dissolves as acid appears, it releases gradually through the day rather than all at once.
Sensitive leaves magnesium out and uses triethyl citrate instead, a plant-derived ester. The same bacterial enzymes that create odor also break this down, and what they release is citric acid, right at the skin's surface. It works inside your skin's own acidity rather than raising it, which is why it's the formula built for reactive skin.
Tea Tree is a different formula altogether, described below.
The base, in all four, is plant oils, absorbers, and waxes that make the stick wearable, with bisabolol from chamomile to keep skin comfortable.
What Makes BioShield™ Different
One Standard. Four Formulas.
BioShield™ powers three of them, each built for a different kind of body. The fourth, Tea Tree, takes its own approach, below.
A Different Approach: Tea Tree + Mineral
Not everyone's skin wants the same thing. Tea Tree + Mineral is the original Zaffré formula, and it's still here, for anyone who prefers a botanical-forward stick.
It follows the same philosophy, no aluminum and no ingredient without a function, but the chemistry is different. Tea tree botanicals lead, with zinc oxide and sage alongside them. Baking soda neutralizes the odor acids and bamboo silica handles the moisture.
Baking soda works. It's also the single most common cause of natural-deodorant rash. That's the trade, and it's why Tea Tree is the only one of the four that uses it. If baking soda has ever given you trouble, buy Sensitive instead. Shop Tea Tree →
Common Questions
Zinc chloride hydroxide captures the odor compounds skin bacteria produce when they break down sweat, and limits bacterial growth alongside that. Rather than masking a smell or blocking sweat, it removes the molecules that carry it. It's the active in Core, Max, and Sensitive.
No. Antiperspirants use aluminum salts to plug sweat glands. Nothing here blocks sweat. You keep sweating and cooling normally, and the odor is what gets interrupted.
Sensitive is the formula built for that question. It's magnesium-free, baking-soda-free, alcohol-free, and Dermatologist Tested. Core and Max contain magnesium hydroxide, well tolerated by most people but still a mineral base, and Tea Tree contains baking soda. If your skin has reacted before, start with Sensitive.
Max is the bigger formula. More of the zinc active, a richer base, and a smoother glide, for hard sweat and long days. Core is the everyday one, magnesium-forward with a drier finish, at a cheaper price. If you've never found one that holds up, start with Max.
Same price, different chemistry. Max uses magnesium hydroxide to neutralize odor acids. Sensitive leaves magnesium out and uses triethyl citrate, which works inside your skin's own acidity. Choose on your skin, not your budget.
Because it isn't the same chemistry. Tea Tree runs on botanicals, zinc oxide, and baking soda, without the zinc chloride hydroxide the other three share. Same standard, different formula, so it keeps its own name.
Keep Reading
Compare All Four Formulas · Every Ingredient, Explained · Deodorant Without Baking Soda: Why It Matters · Why Natural Deodorant Burns
Formulated and Manufactured in the USA