We sweat all year round. But it's in the summer that concerns resurface: "Will my deodorant really last?", "What if it gives me a rash?", "Will it stain my clothes?"
These questions are legitimate. You sweat more when it's hot, so you put your product to a tougher test. And between marketing promises, incomprehensible ingredients, and conflicting opinions on the Internet, it's hard to know what really works.
Here are the 5 questions I get most often — not from marketing, just applied cosmetic chemistry and honest answers, based on experience and science.
Let's go.
1. Why does natural deodorant sometimes fail in summer?
Short answer: Because the formulation wasn't designed to truly neutralize odors under heavy perspiration.
First, understand where the odor comes from. Your fresh sweat is odorless. Odor only appears when the bacteria on your skin "eat" the sweat molecules and release odor-causing compounds.
To prevent odor, you need to act on the bacteria, not on the sweat.
The trap of overly simple formulas: Many natural deodorants rely on a single neutralizing active ingredient, sometimes at too low a concentration. When you sweat more in summer, this single active ingredient is quickly overwhelmed.
What really makes the difference: a synergistic combination of several active ingredients that act at different levels — gently modifying skin pH, neutralizing odor molecules, and directly inhibiting bacteria.
This is exactly the philosophy behind Casabé deodorant: three complementary active ingredients (magnesium hydroxide, elderberry extract, zinc ricinoleate) rather than just one, plus 12 other carefully selected ingredients for performance and comfort. Made in Quebec, in an eco-responsible refillable format.
Formulating a truly effective natural deodorant is a real technical challenge. But it's doable — and you can feel it in use.
2. Why has my natural deodorant given me a rash before?
Short answer: Very often, the culprit is baking soda.
Baking soda (pH ~8-9) is very alkaline, while your skin has a natural pH of around 5.5. This difference can disrupt your skin barrier and cause chemical irritation.
But there's a second problem that's rarely talked about: granulometry. The baking soda used in many deodorants is not finely ground, and its crystals create mechanical abrasion on the delicate skin of the armpits. It's this friction, often invisible but repeated, that aggravates redness.
What about magnesium hydroxide? Isn't it also alkaline?
Good question. Yes, it is technically alkaline (pH 9-10.5 in a concentrated solution). But here's what changes everything: its solubility in water is extremely low (0.00064 g/100 ml at 25°C, which is about 2500 times less soluble than baking soda).
Practically, this means two things:
- It dissolves very slowly and gradually in sweat, releasing its alkalinity gradually. Your skin has time to adapt.
- Its low solubility prevents it from raising the pH of sweat above neutral (~7) — whereas baking soda dissolves instantly and sharply raises the pH.
And an important bonus: the texture of fine powdered magnesium hydroxide is silky, not abrasive — unlike baking soda crystals.
And is the adaptation period important?
Yes, very important, and no one talks about it enough.
If you've been using an aluminum antiperspirant for a long time, your pores have become "accustomed" to being blocked. When you switch to a natural deodorant, your pores gradually unclog. During this phase of 2 to 3 weeks (sometimes called "detox period"), you may experience:
- Sweating that seems more abundant than before
- The need to reapply your deodorant during the day
It's not that the natural deodorant isn't working. It's your body returning to its normal function. Persevere for 2-3 weeks, and the situation will balance out.
💡 Practical tip: start the transition to a natural deodorant at a time when you can reapply freely if needed — not the day before a big presentation at work.
3. Does natural deodorant stain clothes?
Short answer: Not if it's well formulated. But beware, deodorants can stain in two different ways.
The famous yellow stains on white t-shirts do not come from sweat. They come from the chemical reaction between aluminum in antiperspirants and sweat proteins. No aluminum = no yellow stain.
But there are also white stains upon application, caused by formulas that are too greasy, or too concentrated in absorbent starches (like arrowroot or cornstarch) or mineral pigments. Even worse: some natural deodorants form clumps after application — when the absorbent powders meet the heat and friction of the skin, they agglomerate into small dry deposits. This phenomenon is exacerbated when the basic texture of the formula is not sufficiently smooth. These deposits then come off on clothes, whether light or dark.
What makes the difference in a well-formulated deodorant: a silky texture that glides on, doesn't clump, and leaves no visible residue. This is exactly what we worked on for Casabé deodorant — a light texture that penetrates quickly, with no clumps, no stains, neither white nor yellow.
4. Without aluminum, is it really effective?
Short answer: Yes, because effectiveness does not depend on aluminum.
Distinguish between two types of products:
- An antiperspirant (with aluminum) mechanically blocks pores to prevent sweat from escaping. It interferes with your body's natural temperature regulation process.
- A natural deodorant allows you to sweat normally (which is healthy), but prevents bacteria from turning your sweat into odor.
The end result is the same (not smelling bad), but the approach is completely different — and that of natural deodorant respects your physiology.
On health: several studies have raised questions about long-term skin absorption of aluminum. Although the scientific debate is not definitively settled, many choose to reduce their exposure as a precaution — especially in an area so close to the breast.
5. How to recognize a good natural deodorant?
4 criteria to look for on the label:
✓ Aluminum-free AND baking soda-free
The basis. These two ingredients are the main causes of concerns and irritations.
✓ A combination of several neutralizing active ingredients
A single ingredient is almost never enough. Look for a formula that combines several approaches: gentle alkalization, bacterial inhibition, neutralization of odor compounds.
✓ A texture that suits you
A good deodorant should glide on, penetrate quickly, and feel invisible on your skin. Not lumpy, not sticky, not greasy.
✓ A transparent formula, with a clear origin
Check that you can understand all the ingredients. Prioritize brands that manufacture in small batches, under ethical conditions, and that are transparent about the origin of their ingredients.
And the fragrance in all this?
This is a point often overlooked, yet it makes a real difference in everyday life.
Many deodorants — both natural and conventional — are heavily fragranced, sometimes with synthetic fragrances or intense essential oil combinations. The problem: this fragrance clashes with your own perfume, the one you put on your wrist or neck, the one that suits you.
At Casabé, we chose to offer two versions:
- A 100% natural origin fragrance (cranberry, apple, bergamot) that is very soft, designed not to clash with your favorite perfumes.
- A fragrance-free version, for those who prefer zero added scent — also practical if you have reactive skin or if you love to change perfumes often.
In summary
A good natural deodorant is a complex product to formulate. It's not a single miracle ingredient — it's the balance between several active ingredients, a well-thought-out texture, and respect for your skin's physiology.
This is exactly the philosophy behind Casabé magnesium deodorant: 15 ingredients of plant and mineral origin, handmade in Quebec with organic cranberry oil. Refillable in a reusable tube, with compostable cardboard refills. Aluminum-free, baking soda-free, alcohol-free. 🌿
Do you have a question? Send me a private message — I always reply personally.
