We live in a world with (luckily) and increasing focus on health and well-being.

We spend a lot of energy optimizing sleep, diet, exercise and screen time. And I’m part of that too.

But what if something invisible was working against all that effort?

We can eat well, move more and sleep enough, yet still feel drained if our bodies are slowly accumulating toxins.

One place this matters more than ever is cosmetics: we swipe that stuff on our bodies daily - especially deodorants, most people apply every single day.

That’s why I looked into a systematic review by Kazemi et al. (2021).

This review screened hundreds of papers and used 37 studies that looked at everyday cosmetic exposure and health effects.

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Now before we get started, here’s a very simple overview of some of the most common ingredients found in cosmetics - and especially deodorants:

Aluminum:

What it does: Blocks sweat by temporarily plugging sweat ducts.
Why it may matter: Linked to endocrine disruption.

Dichlorobenzyl Alcohol:

What it does: Preservative and antimicrobial agent.
Why it may matter: Can irritate skin and may affect the nervous system with repeated exposure.

Propylene Glycol:

What it does: Helps ingredients absorb into the skin; keeps products moist.
Why it may matter: Increases skin penetration, meaning it can help other chemicals enter the bloodstream more easily.

Phthalates:

What they do: Make fragrances last longer and feel smoother.
Why they may matter: Well-known endocrine disruptors.

Triclosan:

What it does: Antibacterial agent.
Why it may matter: Interferes with thyroid hormones and contributes to antibiotic resistance.

PFAS (“forever chemicals”):

What they do: Improve spreadability and durability.
Why they may matter: Accumulate in the body, disrupt hormones, and are linked to immune, thyroid, and reproductive issues.

Alcohol:

What it does: Dries quickly, kills bacteria, improves feel.
Why it may matter: Can disrupt the skin barrier, increase absorption of other chemicals, and cause irritation with daily use.

From the 37 identified studies in the review we are diving into today, the authors pulled out information on:

-  Pollutants identified in perfumes/colognes

-  Concentrations of pollutants (when measured)

-  Diseases attributed to these products

-  Factors affecting who gets sick

-  Prevention/treatment methods

They found that the most common pollutants identified were:

Phthalates (especially DEP, DBP, DMP), parabens (MP, BP, EP, PP), aldehydes, triclosan, aluminum-based salts, and various volatile organic compounds (VOCs).

For example, in one of the included studies by Duty et al. (2005), authors measured phthalate metabolites in urine samples after perfume use and found:

-Monoester phthalates in 75-100% of people tested
-MEP (monoethyl phthalate) in 100% of samples
-MBP (monobutyl phthalate) in 95% of samples
-MBzP (monobenzyl phthalate) in 90% of samples
-MEHP and MMP in 75% of samples.

Likewise, across studies, the authors found that a set of toxins was routinely found in fragrance cosmetic use: dimethyl octanol, eucalyptol, dimethyl heptenal, alpha-citronellol, methoxy benzaldehyde, limonene, benzylacetone, and decanal.

Moreover, the review found evidence of varying strength linking cosmetic chemical exposure to adverse health effects.

For example, a Swedish population study (Steinemann, 2018) surveyed participants about their fragrance use habits and health symptoms.

They found correlations between perfume exposure and migraines, asthma attacks and respiratory problems.
While these are self-reported associations, the patterns across large populations are concerning.

Even more interesting (or troubling), a study by Huang et al. (2018) examined occupational exposure in perfume sales clerks - people who handle these products daily.

The researchers directly measured phthalate levels and found that "exposure to DBP and DEHP in perfume vendors increases damage to the reproductive system."

The broader implications for endocrine health are equally concerning.

A Danish study found reduced fertility associated with MEP exposure, while Japanese researchers documented that high paraben concentrations in female students correlated with disrupted menstrual cycles and shorter periods.

Beyond reproductive effects, the systematic review documented neurological complications among perfume users, including depression, with Patel (2017) specifically noting that perfumes can cause "neuropathy (depression, autism)" and nervous system damage.

What we know from other studies on the subject is that these chemicals interfere with hormone synthesis, receptor binding, and metabolic regulation, which supports the findings mentioned in todays review.

Simply put: check the back of your deodorant for those ingredients I mentioned earlier.

If they're there, switch it out.

It's important to understand that this is a question of dose.

No single deodorant will cause these effects alone.

It's the accumulation of daily use over years, combined with exposure from multiple sources, that matters.

That's why I recommend one small change today: switch to a deodorant without these harmful chemicals.

When I couldn't find a good solution for myself here in Denmark, I actually decided to create one myself.

I've started a small deodorant brand with two versions that simply don't contain these harmful ingredients.

If you're interested, I just opened preorders this week.
👉 Preorder here.

Articles used for this newsletter:

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