ISDIN Fotoprotector Hydrolotion SPF 50

Dicaprylyl Ether gives a non-greasy feel and better spreadability to products.

Those who are using ketoprofen, a topical anti-inflammatory drug, may experience an allergic reaction when using octocrylene. It is best to speak with a healthcare professional about using sunscreens with octocrylene.

The EU allows a maximum of these concentrations:

Propanediol is not likely to cause sensitivity and considered safe to use. It is derived from corn or petroleum with a clear color and no scent.

Studies have found that avobenzone becomes ineffective when exposed to UV light (it is not photostable; meaning that it breaks down in sunlight). Because of this, formulations that include avobenzone will usually contain stabilizers such as octocrylene.

However, some modern formulations (looking at you, EU!) are able to stabilize avobenzone by coating the molecules.

Avobenzone does not protect against the UV-B range, so it's important to check that the sunscreen you're using contains other UV filters that do!

The highest concentration of avobenzone permitted is 3% in the US, and 5% in the EU.

The ethylhexanol in this ingredient is a fatty alcohol and helps hydrate your skin, similar to oils. It is an emollient, which means it traps moisture into the skin.

According to manufacturers, Ethylhexyl Salicylate absorbs UV wavelength of 295-315 nm, with a peak absorption at 307-310 nm. UVA rays are linked to long term skin damage, such as hyperpigmentation. UVB rays emit more energy and are capable of damaging our DNA. UVB rays cause sunburn.

DHHB has been approved by the EU, Japan, Taiwan, and South America for use up to 10%. Unfortunately, it has not been approved for use in the US or Canada due to slow regulatory processes.

This ingredient is soluble in oils, fats, and lipids.

Ethylhexyl Triazone is oil soluble, oderless and colorless, which mean it is able to be incorporated into a variety of different formulations.

It is not currently available within the United States due to slow changing FDA regulations. Outside of the US, it is used in formulations at concentrations up to 5%.

Due to it being water-soluble, Ensulizole helps give sunscreens a light and non-oily texture.

Ensulizole is approved worldwide:

Your skin makes glycerin on its own (mostly from sebaceous oil breakdown) and shuttles it to your outermost layer of skin, or your epidermis, via aquaporin-3.

Aquaporin-3 is a transporter that is essential for normal skin hydration, elasticity, and repair. Interestingly, mice lacking in AQP3 have dry and less elastic skin that can be fully corrected with glycerin.

This ingredient is non-irritating, plays well with almost every ingredient, and works across all skin types. Typical use is anywhere between 3-10% but can go up to 79% in some leave-on products.

Just know very high concentrations (>40%) can feel tacky in low humidity.

Glycerin is the name for this ingredient in American English. British English uses Glycerol/Glycerine.

Tromethamine helps balance the pH level of a product. Normal pH level of skin is slightly acidic (~4.75-5.5). The acidity of our skin is maintained by our glands and skin biome. Being slightly acidic allows our skin to create an "acid mantle". This acid mantle is a thin barrier that protects our skin from bacteria and contaminants.

Oral Tromethanmine is an anti-inflammatory drug but plays the role of masking, adding fragrance, and/or balancing pH in skincare.

1,3-Propanediol, 2-amino-2-(hydroxymethyl)-

On top of that - it is highly photostable and helps prevent the photodegration of other sunscreen ingredients such as avobenzone.

Tinosorb S is allowed in the EU, Australia, Asia, Canada, and recently approved for use by the US in mid-2026.

Fun fact: Tinosorb S is the most effective UV absorber at maximum concentration (measured by SPF) permitted in the EU.

This ingredient is oil-soluble, so your oil-cleansers will take this right off at night.

You might see people debate whether Sodium Chloride is comedogenic, but there actually haven't been any comedogenic tests done on it. Either way, the overall formulation of a product matters a lot more than any single ingredient.

You might see this ingredient used in scrubs as a primary exfoliating ingredient.

For instance, Habanolide is a proprietary trade name for a specific aroma chemical. When used as a fragrance ingredient in cosmetics, most aroma chemicals fall under the broad labeling category of “FRAGRANCE” or “PARFUM” according to EU and US regulations.

The term 'parfum' or 'fragrance' is not regulated in many countries. In many cases, it is up to the brand to define this term.

For instance, many brands choose to label themselves as "fragrance-free" because they are not using synthetic fragrances. However, their products may still contain ingredients such as essential oils that are considered a fragrance by INCI standards.

One example is Calendula flower extract. Calendula is an essential oil that still imparts a scent or 'fragrance'.

Depending on the blend, the ingredients in the mixture can cause allergies and sensitivities on the skin. Some ingredients that are known EU allergens include linalool and citronellol.

Parfum can also be used to mask or cover an unpleasant scent.

The bottom line is: not all fragrances/parfum/ingredients are created equally. If you are worried about fragrances, we recommend taking a closer look at an ingredient. And of course, we always recommend speaking with a professional.

Because it is not a free-fatty acid or alcohol, this ingredient is fungal acne safe (there's nothing for Malassezia to feed on).

Tocopheryl Acetate is commonly found in both skincare and dietary supplements.

On top of that, this ingredient can counteract the effects of hard water by binding to the minerals in it.

One thing worth knowing is that Disodium EDTA has been shown to be a mild penetration enhancer. It can help other ingredients absorb into skin more effectively which can be a double-edged sword (great for actives, but can also make the active too strong if you have sensitive skin).

Clinical patch testing showed no significant skin irritation at typical use concentrations and minimal dermal absorption.

You'll most likely see this ingredient near the end of an ingredient list. It's typically found in concentrations less than 1%.

Fun fact: This ingredient is commonly used as food additive in Japan.

Topically applied tocopherol has been shown to protect against UV damage by ramping up the skin's own natural defense enzymes.

It also acts as a skin conditioning agent; some studies show that regular topical use can improve the skin's water-binding capacity over 2-4 weeks.

This ingredient is especially loved for being a team player. When combined with Vitamin C, the photoprotective effect of both ingredients roughly doubles and the combo also helps reduce UV-induced DNA damage.

This ingredient has some brightening potential but it's more of a prevention ingredient than spot-fader. Cell studies show it can slow down melanin production but it's worth noting that it's not the most powerful brightener out there.

In formulations, it also serves as a stabilizer that helps protect other oxidation-prone ingredients from degrading.

Concentrations usually range from 0.1-1% in most leave-on products.

This ingredient has a scent that is floral, spicy tropical, and citrus-like.

Naturally occurring Alpha-Isomethyl Ionone may be found in Saccharomyces cerevisiae, or the yeast used to make wine and bread.

The term 'fragrance' is not regulated in many countries. In many cases, it is up to the brand to define this term. For instance, many brands choose to label themselves as "fragrance-free" because they are not using synthetic fragrances. However, their products may still contain ingredients such as essential oils that are considered a fragrance.