Leave-in Treatment
Leave-in Treatment
German Germany
American United States

What's inside

What's inside

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Benefits

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Ingredients Side-by-side

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Ingredients Explained

These ingredients are found in both products.

Ingredients higher up in an ingredient list are typically present in a larger amount.

Emollient, Skin Conditioning, Skin Protecting

Dimethicone is a type of synthetic silicone created from natural materials such as quartz. It is also known as polydimethylsiloxane.

What it does:

Dimethicone comes in different viscosities:

Depending on the viscosity, dimethicone has different properties.

Ingredients lists don't always show which type is used, so we recommend reaching out to the brand if you have questions about the viscosity.

This ingredient is unlikely to cause irritation because it does not get absorbed into skin. However, people with silicone allergies should be careful about using this ingredient.

Note: Dimethicone may contribute to pilling. This is because it is not oil or water soluble, so pilling may occur when layered with products. When mixed with heavy oils in a formula, the outcome is also quite greasy.

Learn more about Dimethicone

This ingredient is derived from guar gum. It is a skin conditioning agent that creates a thin, breathable film to reduce water loss during cleansing.

This leaves the skin feeling soft rather than stripped and also contributes to a creamier lather.

Due to the large molecule size, this ingredient is unlikely to penetrate skin.

Learn more about Guar Hydroxypropyltrimonium Chloride
Emulsifying, Masking, Surfactant

Laureth-4 is a nonionic surfactant made by attaching an average of four ethylene oxide units to Lauryl Alcohol, a fatty alcohol from coconut or palm kernel oil.

In a formula, it does two jobs:

A 2012 assessment found this ingredient is used in leave-on products at up to 21%, which is at the very high end for the category; most cosmetic use is far lower and typically in the single digits.

A true allergy to Laureth-4 is rare; similar alcohol ethoxylates tested negative for skin sensitization in undiluted guinea pig studies, and related compounds were non-sensitizing in Magnusson-Kligman maximization tests.

There is one caveat for this whole ingredient family: ethoxylated surfactants slowly oxidize when exposed to air, and it's the oxidation products, not the fresh material, that act as sensitizers. This is mostly a formulation and shelf life issue.

Dr. James Fulton's rabbit ear test from the 1980's scored this ingredient as a 5 on the comedogenic scale. Fulton himself described the rabbit ear as not an ideal model and the tests used undiluted ingredients on rabbit ears, which are more reactive than human facial skin.

Dr. Draelos later used a human assay on finished cosmetic products and found that products built with so-called comedogenic ingredients are not necessarily comedogenic themselves.

This ingredient can be potentially pore clogging if it appears high in the ingredient list of a leave-on product.

The fungal acne picture is actually reassuring: Malassezia uses fatty acids from its surroundings (C11-24). This ingredient has nothing for the Malassezia yeast to use since it is an alcohol and not an acid.

Supporting this, closely related ethoxylated alcohol detergents like Ceteth-20 get used in Malassezia lab work as neutral carriers to disperse a separately added fatty acid (not as the food source itself).

Learn more about Laureth-4
Perfuming

Linalool is a small, naturally occurring scent molecule found in plants like lavender, coriander, bergamot, and more.

It is one of the two most-used fragrance ingredients in cosmetics and added purely for smell. Since it's not used for a skin benefit, there's no "effective dose". Concentration depends on the fragrance load of the product.

The EU requires it to be named on the label above 0.001% in leave-on and 0.01% in rinse-off products.

Fresh linalool is a weak sensitizer but air exposure turns some of it into hydroperoxides, which are strong sensitizers. Those oxidation products are the actual allergy concern.

Patch-test clinics see positive reactions to linalool hydroperoxides in about 4% to 12% of dermatitis patients depending on country and test concentration.

Resassuringly, one analytical study found hydroperoxide levels in real fragranced products to be orders of magnitude below what induced sensitization in animal studies with no evidence of oxidation building up during normal storage.

The practical takeaway is that linalool is fine for most people but worth avoiding if you have a confirmed fragrance contact allergy or a badly compromised barrier.

Products stored a long time after opening are also the high-risk scenario since that is when oxidation happens.

The scent of linalool is described as floral, spicy tropical, and citrus-like.

Learn more about Linalool
Masking, Perfuming

Parfum is a catch-all term for an ingredient or more that is used to give a scent to products.

Also called "fragrance", this ingredient can be a blend of hundreds of chemicals or plant oils. This means every product with "fragrance" or "parfum" in the ingredients list is a different mixture.

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.

Learn more about Parfum
Preservative

Phenoxyethanol is one of the most widely used preservatives in skincare (and for good reason!).

It has a large spectrum of antimicrobial activity and especially effective bacteria, yeast, and mold while only having a weak effect on your skin's natural microbiome.

On a cellular level, it disrupts the cell membranes of microbes by poking holes that make the cell leak. This shuts down the chemical reactions the microbe needs to make energy so it can no longer survive.

Another perk of this ingredient is that it stays functional across a wide pH range (3-10).

You'll often see it paired with boosters like Ethylhexylglycerin; one study showed that a 1:9 ratio of Ethylhexylglycerin to Phenoxyethanol damages bacterial membranes as effectively as doubling the Phenoxyethanol concentration on its own.

Typical use concentrations range from 0.3-1% depending on the formula, and this ingredient is capped at 1% int the EU.

Safety-wise, the fear mongering does not hold up to the evidence. The EU's Scientific Committee on Consumer Safety and FDA consider it safe as a preservative at up to 1%, including for children of all ages.

Adverse systemic effects only showed up in animal studies at exposures roughly 200x higher than what people get from cosmetics. And despite its very widespread use, this ingredient is a rare sensitizer and allergic reactions are uncommon.

Learn more about Phenoxyethanol
Skin Conditioning, Solvent

Water. It's the most common cosmetic ingredient of all. You'll usually see it at the top of ingredient lists, meaning that it makes up the largest part of the product.

So why is it so popular? Water most often acts as a solvent - this means that it helps dissolve other ingredients into the formulation.

You'll also recognize water as that liquid we all need to stay alive. If you see this, drink a glass of water. Remember to stay hydrated!

Learn more about Water

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