SUN

Why I only use mineral UV filters

By founder, Mette Skjærbæk

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WHAT SUNCARE DO YOU WEAR?

An important decision for skin and health

When we ask, “What suncare do you wear?”, we’re not looking for the perfect answer – but for awareness. With the recent relaunch of Karmameju Sun, founder Mette Skjærbæk shares why choosing the right sunscreen is an important decision – for both our skin and overall health.

You’ll also learn about the differences between sunscreen filters, and why Mette chooses to use only mineral sun filters – for herself, for her daughters, and for everyone who uses Karmameju.

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Why choose mineral filters?

My reasons for choosing exclusively mineral sun filters are many, but above all they come down to safety.

My decision to avoid nano and chemical sun filters is mainly based on the precautionary principle. Regulations concerning chemical sun filters are continuously updated in light of new scientific assessments. Nanotechnology in skincare is still an evolving field of research; therefore, we have always chosen to avoid both and use only mineral filters for the safety of our consumers.”

For me, mineral sun filters are the only truly safe choice — and they have been ever since my twenties, when I first became aware of how skincare ingredients can affect our vital body systems and overall health.

Mineral sun filters are an essential part of Karmameju’s holistic values. They are part of the promise I have made to those who use Karmameju — and the choice I wish to pass on to my daughters.

Since the 1990s, I have used only mineral sunscreen on my family and myself. And it is such a joy that Karmameju’s formulas no longer leave the skin sticky or white, as mineral sunscreens often did in the past.

There are many advantages to mineral sun filters:
– They work immediately after application
– They occur naturally in the earth
– They provide broad-spectrum protection instantly
– They do not clog the skin
– They do not leave permanent yellow stains on clothing
– They do not sting the eyes
– They are recommended for children
– They are recommended for sun allergy and rosacea

Developing Karmameju SUN has not been easy. With the first version of our mineral sunscreen, I felt we reached about 90% of the way in making it invisible on the skin and easy to apply. With the new version (2025), I believe we have finally achieved our goal.

The “easy” solution would have been to use chemical sun filters, mineral filters in nano form, or add silicone to the formula to make it easier to spread. None of these three options align with my holistic values.

We do not use mineral nano sun filters - where particles are made microscopically small through nanotechnology - based on the precautionary principle.

Chemical sun filters only work once they have penetrated beneath the skin’s surface, through a chemical process that converts UV rays into heat. Over the years, more and more chemical sun filters have been suspected or documented to be endocrine disruptors, or to be contaminated with endocrine-disrupting substances during their development process*. As a result, chemical UV filters are continuously being regulated, restricted or phased out following new scientific evaluations. This is a development I follow closely, and one that continues to confirm my decision to use only mineral sun filters. It is the promise I have made to those who use Karmameju — and the choice I wish to pass on to my daughters.

Fortunately, we have succeeded in creating a sun care range based on the mineral sun filter zinc oxide. In our updated formula (2025), it continues to provide optimal broad-spectrum protection, while now being even easier to apply. Most importantly, which was our greatest challenge – our new mineral sun filter is invisible on the skin.

It brings me great joy that we have succeeded in creating such a beautiful, nurturing sunscreen based solely on mineral sun filters. As I see it, there is no longer any reason to use anything other than mineral sun filters.

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SPF – essential for longevity

It’s my mission to inform people that their sunscreen choice is an important decision for both our skin and our health. Skin is our body’s largest organ, and plays a crucial role in our overall health. Think about how medication applied via creams, gels (e.g. EstroGel) or patches, then absorbed through the skin and distributed throughout the body. Our skin, with its delicate pH and microbiome, is a vital part of our wellbeing. The health of our skin has been scientifically documented as essential for longevity – you can read more about that in this article I wrote on how skin health is key to human longevity​.

“It’s my mission to inform people that sunscreen choice is an important decision – for both our skin and our health.”

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SPF - essential for longevity

It’s my mission to inform people that their sunscreen choice is an important decision for both our skin and our health. Skin is our body’s largest organ, and plays a crucial role in our overall health. Think about how medication applied via creams, gels (e.g. EstroGel) or patches, then absorbed through the skin and distributed throughout the body. Our skin, with its delicate pH and microbiome, is a vital part of our wellbeing. The health of our skin has been scientifically documented as essential for longevity – you can read more about that in this article I wrote on how skin health is key to human longevity​.

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What’s the difference between mineral and chemical UV filters?

Mineral sun filters, such as our non-nano zinc oxide, protect the skin by absorbing UV radiation while also reflecting and scattering part of the radiation away from the skin’s surface - which means protection is immediate.

Chemical sun filters must penetrate the skin, where they absorb UV rays and convert them into heat through a chemical reaction. Personally, I don’t like the idea that chemical filters only start working after 20 minutes**. I prefer mineral filters which work immediately.

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Mineral suncare you’ll want to use again and again

Together with our highly valued manufacturer in Southern Italy, with organic agriculture, we’ve solved the challenge of making mineral suncare lovely to use - repeatedly throughout the day.

The balance of the right ingredients has enabled us to succeed in the reformulation of SUN 2.0, making even an SPF 50 that does not leave a white cast on the skin and feels great on the skin. At Karmameju, we are not just making suncare for your protection; the products are antioxidant-rich, nurturing skincare as well, ensuring your skin thrives, even under the harsh rays of the sun.

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The three types of UV filters

- Mineral filters (also called physical filters), used by Karmameju

- Nanoparticle filters (filters in nano form)

- Chemical filters

Mineral filters
Mineral (physical) sun filters, Zinc Oxide (used by Karmameju) and Titanium Dioxide, consist of minerals naturally derived from the earth. Mineral sun filters protect the skin by absorbing UV radiation while also reflecting and scattering part of the radiation away from the skin’s outermost layer - which means the protection is immediate. Research suggests they are photostable and less likely to cause irritation***. Though mineral sunscreens used to be hard to apply and left a white cast, that’s not the case with Karmameju SUN.

Mineral/physical UV filters: Zinc Oxide. Titanium Dioxide.****


Nano-particle filters

Many ingredients can be made in a microscopic nano size. For example, physical sun filters have been developed in nanoform to make them less visible on the skin – and therefore less white. Unfortunately, there is uncertainty about how deeply they can penetrate into the body. Very little is known about the potential risks associated with nano-particles in general. Ingredients in nanoform are always listed with “nano” in parentheses after the name, for example, Titanium Dioxide (nano), so that consumers can see that nano ingredients have been used in the product. Karmameju does not use nano sun filters.

Nanoparticle UV filters: All UV filters listed with (nano) in parentheses after the ingredient name.****


Chemical filters
Chemical sun filters
are synthetic. When UV rays hit the skin, these filters absorb the UV radiation and convert the rays into heat within the skin through a chemical process. Studies show that chemical sun filters can penetrate the skin barrier (dermis), can be measured in the bloodstream, and may cause skin irritation or trigger sun allergy.*** Chemical filters are invisible on the skin, which is why many brands use them. However, no chemical filters are approved by “green” or natural certifications such as ECOCERT/COSMOS. Karmameju does not use chemical filters.

Chemical UV filters: Diethylamino Hydroxybenzoyl Hexyl Benzoate. Ethylhexyl Triazone. Bis-Ethylhexyloxyphenol Methoxyphenyl Triazine. Diethylhexyl Butamido Triazone. Ethylhexyl Salicylate. Octocrylene. Oxybenzone. Avobenzone. Octinoxate. Tinosorb. Ethylhexyl Methoxycinnamate. Homosalate. 4-Methylbenzylidene Camphor (4-MBC)1 May 2026: All existing products containing the filter 4-MBC must be removed from shop shelves. etc.****

Most of us love the sun – myself included – and there are many benefits to soaking up its warm rays. But using safe sunscreen is crucial for our health and safety.

Consumer safety is the guiding star in our product development.
Thank you for your trust in Karmameju – it means the world.


With love,

Mette Skjærbæk
Founder of Karmameju Skincare

*The Danish Health Authority on the chemical sunscreen 4-MBC, which is no longer authorised for use in sunscreens within the EU (link)

*Study conducted by the German authorities, which found the endocrine-disrupting phthalate DnHxP in 50% of the 40 sunscreens tested containing the chemical UV filter DHHB on the German market (link)

*A study from Rigshospitalet (a leading Danish hospital) found residues of an endocrine-disrupting sun filter in follicular fluid samples from couples undergoing fertility treatment (link)

** The Danish Health Authority (2025) on application of sunscreen 20 min. before sun exposure (link)

*** About the link between sun eczema and sunscreens (link)(link)

****The above lists were written in March 2026. Legislation regarding which UV filters are considered safe for consumers is continuously evolving, so always make sure to seek updated information about your sunscreen at the given time.

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Founder of Karmameju Skincare, Mette Skjærbæk and daughters

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