Baking soda isn't "bad" in the toxic sense — it's in your fridge, your pancakes, and half the cleaning hacks on the internet. The problem is what it does on the very specific real estate of your underarm.

Why it's in there

Baking soda — sodium bicarbonate — fights odor through alkalinity. Odor-causing bacteria prefer a certain pH range, and raising the pH makes the environment less hospitable to them. It's cheap, easy to formulate with, and effective in mild conditions. That's why it's the default active in so many natural sticks.

The actual problem

Your skin maintains a mildly acidic surface — the "acid mantle" — that's part of its protective barrier. Baking soda sits well above that on the pH scale. Apply an alkaline ingredient repeatedly to a warm, damp, high-friction area like the underarm, and for a lot of people it disrupts that barrier: burning, redness, and sometimes a rash. It's not toxicity — it's a topical pH mismatch. Which is why it can show up even if you've used it for a while, and why it bothers some people and not others.

So, is it bad?

Not dangerous. But if your skin is among the many that react, it's the wrong ingredient for this job — and "power through the irritation" is bad advice. The fix isn't to suffer; it's to switch to a formula that controls odor without the alkaline hit. (We go deeper on that in deodorant without baking soda.)

That's the design behind SENSITIVE: baking-soda-free and fragrance-free, controlling odor through the zinc-based BioShield™ system that eliminates it at the source rather than shifting your skin's pH to fight it. Clinically tested at 0% irritation — which is the whole point of taking the baking soda out.

→ SENSITIVE — baking-soda-free, and built to still work.