What Does Baking Soda Do in a Deodorant Formula—And Why Do Some People React?
Baking soda is a common effective odor control ingredient found in the better working natural deodorants—and for good reason. It does a great job neutralizing odor!
But if you’ve ever used a natural deodorant and ended up with redness, bumps, or a rash under your arms, it’s possible that baking soda was the culprit.
Let’s take a closer look at how baking soda works in deodorant, and why it causes irritation for some people.
How Baking Soda Works in Deodorant
It Neutralizes Odor-Causing Acids – Body odor isn’t caused by sweat itself (which is mostly water and salt), but by bacteria breaking down components of sweat—especially fatty acids and proteins—into volatile compounds that smell.
Baking soda is mildly alkaline, so it neutralizes these acidic byproducts, making them less smelly.
It Has a Mild Antimicrobial Effect – Bacteria thrive in warm, moist environments like the underarm. Baking soda’s alkalinity makes the environment less favorable for odor-causing bacteria, reducing their activity and growth.
It Has Absorbent Qualities – While not as strong as clay or starch, baking soda does help absorb some moisture, which also indirectly helps reduce odor since bacteria multiply more quickly in damp conditions.
It’s a simple, natural, and effective solution for many people.
So Why Does Baking Soda Cause Irritation?
Baking soda is alkaline. For some people, it disrupts the skin's natural pH balance too much, leading to:
- Redness
- Burning or stinging
- Small bumps or itchy rashes
This irritation can appear after just one use—or after months of using a product that had been fine. Changes in body chemistry, caused by detox or hormonal shifts, can also cause a deodorant that used to be fine to suddenly cause reactions.
How to Know If Baking Soda Is the Problem
Here are a few signs that your deodorant might not be a good match for your skin:
- Your rash is only in the underarm area (and not elsewhere)
- The irritation shows up after switching deodorant formulas (read the ingredients in the previous deodorant and current deodorant and narrow down what is new)
- You’ve ruled out shaving, fragrance/essential oils, fabric allergies, and other causes
If you want to know for sure if the baking soda is the problem, you can make a paste of water and baking soda (the regular stuff you have in your kitchen is all you need)—apply it to your armpits and see what happens. OR just try a baking soda-free formula.
What to Use Instead of Baking Soda
How Zinc Works in Baking Soda–Free Deodorant
Two different forms of zinc are commonly used in baking soda–free deodorants, and while they sound similar, they work in distinct ways.
Zinc oxide helps control odor by creating an environment that’s less favorable for odor-causing bacteria, while also soothing and protecting sensitive skin. It’s the same ingredient used in many diaper rash creams and skin protectants, which is why it’s often included in formulas designed for easily irritated underarms. Because zinc oxide is naturally white, deodorants that use it may apply with a visible white cast.
Zinc ricinoleate works differently. Instead of affecting bacteria, it binds to and traps odor molecules so they can’t be detected. This allows for effective odor control without altering skin pH or irritating sensitive skin, and it applies clear.
Both forms of zinc can be effective alternatives to baking soda, and which one works best often comes down to your skin’s sensitivity and how your body produces odor.
At Island Deodorant, we offer four formulas so you can choose what works best for your body:
- Original Formula – With baking soda for maximum protection
- Extra Strength Sensitive – Uses a reduced amount of baking soda (1/3 strength) along with zinc oxide and other odor fighters for better tolerance
- Sensitive Clear – Baking soda free and uses zinc ricinoleate and magnesium hydroxide for odor control without irritation
- Sensitive Formula – Baking soda-free and uses zinc oxide and magnesium hydroxide, designed for ultra-sensitive skin, goes on white
All of our deodorants are unscented, aluminum-free, and made with clean, organic ingredients.
Frequently Asked Questions
Q: Why does baking soda work for some people but not others?
A: Everyone’s skin is different. Some people have more resilient skin or sweat with a different pH balance, while others are more prone to pH disruption and irritation.
Q: Can I build a tolerance to baking soda?
A: Some people find they can use low-baking-soda formulas like our Extra Strength Sensitive, even if they can’t tolerate higher levels. Others need to avoid it entirely.
Q: Is there anything better than baking soda?
A: Not necessarily better—“better” will depend on your skin and odor situation. But magnesium hydroxide, zinc oxide and zinc ricinoleate can all be effective odor fighters. They’re featured in our Sensitive and Sensitive Clear formulas.
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