Here is the part about deodorant that I think gets missed:

Sweat itself is not really the problem.

Your armpits are supposed to sweat.

The smell happens largely because bacteria living on the skin take compounds in our underarm secretions and turn them into volatile, smelly molecules.

Which means there are two very different ways to approach body odour:

stop the sweat

or

change what happens once the sweat reaches your skin.

Magnesium deodorant is firmly in the second camp.

First: deodorant and antiperspirant are not the same thing

We tend to use the words interchangeably, but they have different jobs.

Antiperspirant reduces sweating.

Deodorant reduces odour.

That distinction matters to me.

I am not particularly interested in making my armpits stop being armpits.

Sweating is normal.

So the goal with deodorant isn't necessarily to create a bone-dry underarm for 24 hours.

The goal is much simpler:

I want to sweat without smelling terrible.

Why does sweat smell?

Fresh sweat isn't the same thing as body odour.

Your underarms contain sweat glands, sebaceous glands and a whole community of microorganisms living on the skin.

Some of the compounds released into the armpit are basically odour precursors.

Then bacteria get involved.

They metabolize those compounds and release the characteristic fatty, sulfurous and otherwise extremely recognizable smells we collectively call B.O.

So technically, what you're smelling isn't just “sweat.”

It's sweat + skin + bacteria + bacterial metabolism.

Very glamorous.

So where does magnesium come in?

Magnesium-based deodorants are designed to change the environment of the underarm so that odour-producing activity is less favourable.

Depending on the form of magnesium being used, magnesium ingredients can affect things like:

• local pH
• moisture
• bacterial growth or activity
• the conditions in which odour-forming reactions happen

The goal isn't to sterilize your armpit.

Your skin has a microbiome. I don't think the answer to everything is to carpet-bomb it.

We just want to make the environment less conducive to smell.

What about pH?

Your underarm has its own local chemistry, and pH influences which microorganisms grow well and how active they are.

This is one reason deodorant formulations can work without physically blocking sweat glands.

Change the environment and you can change what happens to the sweat after it appears.

There isn't one magical “correct” armpit pH that every deodorant needs to achieve, and different deodorant ingredients work differently.

But the general principle matters:

body odour is biochemical.

It's not dirt escaping from your body.

Why can magnesium deodorant sting?

This is probably one of the most common questions with topical magnesium in general.

Freshly shaved skin, irritated skin or tiny invisible nicks can sting when certain mineral salts are applied.

Your underarm is also:

warm

moist

frequently shaved

constantly rubbing against itself.

Not exactly an undisturbed patch of forearm skin.

If deodorant suddenly burns after shaving, that doesn't necessarily mean you've developed some profound magnesium intolerance.

The skin barrier may simply be irritated.

Give it a minute.

Or shave at a different time than you apply your deodorant.

Does magnesium deodorant stop sweating?

Not in the same way an antiperspirant is designed to.

And personally, that's not what I want from it.

You may still sweat.

On a hot day, you should still notice yourself sweating.

During exercise, you should still sweat.

When you're nervous before giving a presentation to 200 people, your body may absolutely ignore the deodorant industry's feelings about the situation.

The measure of a deodorant isn't necessarily:

Did my armpit remain perfectly dry?

It's:

Did I smell?

Different job.

What about baking soda?

A lot of natural deodorants use sodium bicarbonate because altering underarm chemistry can be very effective for odour.

It also irritates the absolute hell out of some people's skin.

Red.

Raw.

Itchy.

Rashy.

If you've ever thought, Natural deodorant just doesn't work for me, it may actually have been that particular natural deodorant formula that didn't work for you.

The entire category isn't one product.

Magnesium gives formulators another way to approach odour control.

Why does natural deodorant sometimes seem to “stop working”?

Body odour can change with:

• stress
• hormones
• heat
• clothing
• diet
• activity
• shaving
• washing habits
• medications
• changes in the underarm microbiome

And your deodorant is working inside that changing environment.

So if something that usually works wonderfully suddenly seems less effective, look at what else changed.

More deodorant is not always better

This is one of those products where people can get enthusiastic.

If a small amount works, covering your entire ribcage in it probably isn't going to work twelve times better.

Apply enough to cover clean underarm skin.

Give it a moment to settle.

Then go live your life.

The way I think about body odour now

Body odour is information.

Not necessarily alarming information.

Just information.

You ate something different.

You're stressed.

You're in a different phase of your cycle.

You've been sweating all afternoon.

Your clothes aren't breathing well.

Your underarm environment changed.

I don't think every normal human smell needs to become a medical problem.

I also don't particularly want to stink.

Both things can be true.

That's where deodorant sits for me.

Not:

STOP MY BODY FROM DOING ANYTHING.

More like:

Carry on with the sweating. Let's just keep the bacterial aftermath under control.

And that is essentially what I want from a magnesium deodorant.

Sweat can stay.

The smell can go.

For the story of how I got here, read Natural Deodorant: Why Body Odor Is a Signal (and How Magnesium Fixed Mine). The one we make is Mag Stick.