Short answer: yes, when the formula puts real odor fighters in baking soda's place. Ours uses two, zinc oxide and magnesium hydroxide. Below is what published research says about each one, and where the research stops. We make a baking soda line too, and it is our extra strength option. This post is for the people who chose the other line and want to know it is not the weak one.
What an Odor Fighter Has to Do
Sweat is nearly odorless. Bacteria on your skin, mostly Corynebacterium and some Staphylococcus, break it down into the compounds you smell. A deodorant has two jobs: make the underarm a harder place for those bacteria to grow, and neutralize the odor compounds themselves. Baking soda does both. Zinc oxide and magnesium hydroxide do both, by different routes. The full story of how odor forms is in our guide to why armpits smell.
Zinc Oxide: In the First Deodorant, and in a 2020 Trial
Zinc oxide is a white mineral powder that has been used in skin preparations for a very long time. The first commercial deodorant, Mum, was built on it, a detail noted in the study below.
In 2020, researchers at the University of Copenhagen published a randomized, double-blind, placebo-controlled trial in Acta Dermato-Venereologica. Thirty healthy adults applied a 1.1% zinc oxide cream to one armpit and the same cream without zinc oxide to the other, once a day for 13 days. Nobody knew which side was which.
What they found. Total bacteria dropped on the zinc oxide side, and so did the two odor makers the researchers tracked, Corynebacterium and Staphylococcus hominis. Thirteen participants noticed a difference between their two armpits, and 11 of those 13 said the zinc oxide side smelled less. Skin pH on the zinc oxide side rose by about half a point. The paper also points to earlier work showing zinc oxide can bind the short-chain fatty acids that make up much of the smell.
What to keep in mind. Thirty people, 13 days. The zinc oxide was in a water-based cream, not a balm like ours. The formulations and some of the funding came from Colgate-Palmolive. It is one trial on the ingredient, not a trial on our deodorant. We are showing you the ingredient's track record, not claiming a study on our product.
Magnesium Hydroxide: What the Chemistry Says, and What It Does Not
Magnesium hydroxide is the same compound as milk of magnesia, the antacid. It is alkaline, like baking soda, and that is the property that makes an underarm a harder place for odor bacteria to grow. The difference is how much of it dissolves. Baking soda dissolves easily in water and sweat. Magnesium hydroxide barely does: about 7 milligrams in a liter of water, and the little that dissolves sits near pH 10.4, per University of Sydney chemistry teaching material. The rest stays where you put it, as a fine solid. That is why it is the pick for skin that reacts to other natural deodorants. Far less of it goes into solution against your skin.
Here is where we stop. We looked for a clinical trial of magnesium hydroxide on underarm odor and did not find one. The case for it rests on that chemistry and on a formula that has been sold for over a decade, not on a published study. We would rather say that than pretend.
How They Work Together in Ours
Zinc oxide and magnesium hydroxide handle odor. Organic arrowroot powder absorbs surface moisture. Organic coconut oil and organic shea butter carry it all and condition the skin. No aluminum, no parabens, no synthetic fragrance, no petroleum, and the baking soda-free line is vegan. The baking soda-free stick comes in Unscented, Orange Vanilla, Coconut Lime, Charcoal Seaside, Jasmine, Lavender, Woodlands, and Vanilla Peppermint. The baking soda-free jar comes in Unscented, Lavender, and Unscented Charcoal.
Who Should Pick Baking Soda-Free
- Anyone whose skin has reacted to a natural deodorant before.
- Anyone who shaves often and wants the milder option for the days after.
- Anyone who would rather start gentle and step up later if they need to.
If you are still deciding, our baking soda vs. baking soda-free guide walks through it.
How to Give It a Fair Two Weeks
- Clean, dry skin. Two or three swipes of the stick, or a pea-sized amount of paste.
- Coming off antiperspirant? Give your body two weeks to adjust. Our switching guide explains what happens in that window.
- Reapply before a workout or a long day. A travel mini makes that easy.
- If odor wins on your heaviest days, step up to the extra strength baking soda stick. Both lines share the same base.
Frequently Asked Questions
Is baking soda-free deodorant weaker?
Not when something real replaces the baking soda. In ours, zinc oxide and magnesium hydroxide do the work. The zinc oxide trial above is the kind of evidence the word "weaker" has to answer to.
Does baking soda-free deodorant stop sweat?
No. Nothing without aluminum does. Arrowroot absorbs surface moisture, and you still sweat your normal amount. Only antiperspirant reduces sweating, and it does that with aluminum.
What does zinc oxide do in deodorant?
In the 2020 trial it lowered the counts of odor-causing bacteria, and most people who noticed a difference said the zinc oxide side smelled less. Earlier work also shows it can bind the fatty acids behind the smell.
Can I switch between the two lines?
Yes. Same base, same scents in the sticks, different odor fighter. Some customers keep both and pick by the day.
The Frank Bottom Line
Baking soda-free works when the replacement works. Zinc oxide has a placebo-controlled trial behind it. Magnesium hydroxide has clear chemistry and a decade of use behind it, and no trial yet, which we would rather tell you than hide. Start with the baking soda-free stick or jar. If you need more on your heaviest days, the extra strength baking soda stick is right there.
Sources: Ågren et al., Acta Dermato-Venereologica 2020; University of Sydney, magnesium hydroxide solubility and pH
