Versus

K18 Hair Leave-In Molecular Repair Hair Mask Versus Kérastase Resistance Strengthening Hair Mask for Extremely Damaged Hair

Hair Mask
Hair Mask
American Brand United States
French Brand France

Overview

What they are

These products are both reef safe hair masks. They have a total of 8 ingredients in common

Suited For

They're both likely to be good for dry skin and scar healing

Free From

They both do not contain any parabens or silicones

What's Inside

They both contain harsh alcohols, common allergens and fragrances

We independently verify ingredients, and our claims are backed by peer-reviewed research. Spot a product that needs an update? Let us know.

Ingredient Info

Click any item below to learn more and see relevant ingredients

About this product

About this product

At a glance

Click on any of the items below to learn more

Key Ingredients

Benefits

Concerns

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

found in both products

Ingredients Explained

These ingredients are found in both products.

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

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. Stay hydrated!

Learn more about Water
Emollient, Emulsifying, Emulsion Stabilising

Cetearyl alcohol is a mixture of two fatty alcohols: cetyl alcohol and stearyl alcohol. It is mainly used as an emulsifier. Emulsifiers help prevent the separation of oils and products. Due to its composition, it can also be used to thicken a product or help create foam.

Cetearyl alcohol is an emollient. Emollients help soothe and hydrate the skin by trapping moisture.

Studies show Cetearyl alcohol is non-toxic and non-irritating. The FDA allows products labeled "alcohol-free" to have fatty alcohols.

This ingredient is usually derived from plant oils such as palm, vegetable, or coconut oils. There is debate on whether this ingredient will cause acne.

Due to the fatty acid base, this ingredient may not be Malassezia folliculitis safe.

Learn more about Cetearyl Alcohol
Emollient, Skin Conditioning

Cetyl Esters is a synthetic wax made up of mostly fatty acids and fatty alcohols. It is strcturally similar to wax taken from whales.

As an emollient, it creates a thin barrier on the skin. This barrier prevents moisture from escaping.

This ingredient may not be fungal-acne safe.

Learn more about Cetyl Esters
Buffering, Masking

Citric Acid is an AHA derived from citrus fruits (think oranges, lemons, and limes!).

As an AHA, Citric Acid removes the top layer of skin cells from the newer layer of skin underneath. This helps skin to remove dark spots and even out skin tone.

If you spot Citric Acid near the end of an ingredient list, it's likely there as a pH adjuster rather than an active ingredient.

Read more about some other popular AHA's here:

Learn more about Citric Acid
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
Perfuming, Tonic

Geraniol is used to add fragrance/parfum to a product. It is the main component of citronellol. It is a monoterpenoid and an alcohol.

Monoterpenes are naturally found in many parts of different plants.

Geraniol can be found in many essential oils including Rose Oil and Citronella Oil. The scent of Geraniol is often described as "rose-like". Many foods also contain Geraniol for fruit flavoring.

Geraniol can irritate the skin when exposed to air. However, irritation depends on the ability of geraniol to penetrate into the skin. In general, geraniol is not able to penetrate skin easily.

Geraniol is colorless and has low water-solubility. However, it is soluble in common organic solvents.

Like citronellol, it is a natural insect repellent.

2,6-Octadien-1-ol, 3,7-dimethyl-, (2E)-

Learn more about Geraniol
Perfuming

Linalool is a fragrance and helps add scent to products. It's derived from common plants such as cinnamon, mint, citrus, and lavender.

Like Limonene, this ingredient oxidizes when exposed to air. Oxidized linalool can cause allergies and skin sensitivity.

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

Learn more about Linalool
Perfuming, Preservative, Solvent

Benzyl Alcohol is most commonly used as a preservative. It also has a subtle, sweet smell. Small amounts of Benzyl Alcohol is not irritating and safe to use in skincare products. Most Benzyl Alcohol is derived from fruits such as apricots.

Benzyl Alcohol has both antibacterial and antioxidant properties. These properties help lengthen the shelf life of products. Benzyl Alcohol is a solvent and helps dissolve other ingredients. It can also improve the texture and spreadability.

Alcohol comes in many different forms. Different types of alcohol will have different effects on skin. This ingredient is an astringent alcohol.

Using high concentrations of these alcohols are drying on the skin. They may strip away your skin's natural oils and even damage your skin barrier. Astringent alcohols may also irritate skin.

Other types of astringent alcohols include:

According to the National Rosacea Society based in the US, you should be mindful of products with these alcohols in the top half of ingredients.

Any type of sanitizing product will have high amounts of alcohol to help kill bacteria and viruses.

Learn more about Benzyl Alcohol

When to use

63 Routines
46% use in am
54% use in pm
56% use every day
When to use See routines that use it ->

Reviews

Here's what our community thinks

K18 Hair Leave-In Molecular Repair Hair Mask 21 ingredients

4.7 /5
from 3 ratings
Soft (1)
BrittanyBotkins_920's avatar

BrittanyBotkins_920

2 years ago
Review

Repaired my extremely bleach damaged hair as well as both of their shampoos.

wednesdayophelia's avatar

Mica

5 months ago
Review

This saved my badly damaged bleached hair.

#soft

Kérastase Resistance Strengthening Hair Mask for Extremely Damaged Hair 29 ingredients

Resistance Strengthening Hair Mask for Extremely Damaged Hair hasn't been rated yet.
Rate it now