Why Natural Deodorant Causes a Rash (Baking Soda Guide)

TL;DR: If your "natural" deodorant left you red, itchy, or rashy under the arms, the ingredient list is probably to blame — specifically baking soda. It's alkaline, your skin isn't, and that mismatch is a documented cause of underarm irritation. No No Funk Natural Deodorant skips baking soda entirely, using magnesium hydroxide and zinc ricinoleate to control odor without the pH fight.

The switch that goes wrong

You ditch the aluminum stick, reach for something with a shorter ingredient list, and a week later your underarms are angry at you. Red. Itchy. Sometimes flaking. It's such a common story that "natural deodorant rash" is basically its own genre of internet complaint — and it's rarely a coincidence.

The baking soda problem, explained

Baking soda (sodium bicarbonate) is a brilliant odor absorber in a fridge. On skin, it's a different story. Baking soda sits around pH 9 — strongly alkaline — while healthy skin runs closer to pH 5. That gap matters: research reviewed by Healthline notes that applying an alkaline substance like baking soda can upset your skin's natural pH balance, which "may lead to dryness, itching, redness, and irritation, especially if you have sensitive skin."

Underarm skin is thin, warm, and freshly shaved more often than most — exactly the conditions where a pH mismatch shows up fastest. It's not a flaw in your skin. It's a formulation choice, and it's an easy one to check: baking soda shows up on ingredient lists as "sodium bicarbonate," and if it's near the top, it's doing most of the odor-fighting work in that formula.

None of this means natural deodorant as a category is the problem. It means the specific ingredient doing the heavy lifting matters more than the word "natural" on the front of the packaging.

Neutralizing odor without the pH fight

Here's the part most "clean" deodorant labels skip: you don't need baking soda to control odor. No No Funk Natural Deodorant is baking-soda-free, full stop. Instead of an alkaline shock to the skin, it leans on magnesium hydroxide — a gentler odor-neutralizer that does its job without the sharp pH spike — paired with zinc ricinoleate, which works by trapping odor molecules rather than masking them with fragrance.

Arrowroot powder and kaolin absorb excess moisture, shea butter, cocoa seed butter, and candelilla wax form the balm base that actually glides on, and tocopherol (vitamin E) conditions skin while the rest of the formula works. Nine ingredients. No baking soda. Naturally derived, aluminum-free, vegan and cruelty-free.

No No Funk Natural Deodorant

This is a deodorant built for the people baking soda burned. It's small, lightweight, and travel-friendly, and it's formulated to keep you funk-free for 24 hours — without asking your underarm skin to tolerate an alkaline paste to get there. Right now it comes Unscented, with Lavender Rose and Vanilla Coconut landing in about a month.

Try No No Funk Natural Deodorant and see what odor control feels like without the rash.

Is it normal for natural deodorant to cause a rash?

It's common, and baking soda is the most frequently cited cause. It doesn't mean your skin is "too sensitive" for natural deodorant generally — it usually means that specific formula isn't right for you.

Will No No Funk stop me sweating?

No — and it's not supposed to. No No Funk is a deodorant, not an antiperspirant. It's formulated to control odor, not wetness. General information, not medical advice; if irritation persists, check in with a dermatologist.

How do I know if baking soda is in my current deodorant?

Check the ingredient list for "sodium bicarbonate" — that's baking soda by its chemical name. If it's high on the list, it's doing a lot of the work.

Sources

Healthline, medically reviewed by Cynthia Cobb, DNP, APRN, WHNP-BC, FAANP — "Baking Soda as a Deodorant: What Are the Benefits and Side Effects?"

Real ingredients. Real results.

Why Natural Deodorant Gives You a Rash (And How to Stop It)