Hair Mask
Hair Mask
American United States
British United Kingdom

What's inside

What's inside

Key Ingredients

Benefits

Concerns

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

You may know this ingredient as argan oil. It has emollient and skin conditioning properties that help soften skin and reinforce the lipid barrier.

The fatty acid profile of argan oil is roughly 45-55% oleic acid, 28-36% linoleic acid, 10-15% palmitic acid, and 5-7% stearic acid. It also contains vitamin E, sterols, squalene, and polyphenols like ferulic acid.

Two clinical studies in postmenopausal women found that applying argan oil for 60 days significantly improved skin elasticity and moisturization (reduced transepidermal water loss and increased epidermal water content).

Since it is high in oleic and linoleic acid, this ingredient may not be fungal acne safe. Both of these fall in the C11-C24 range that Malassezia yeast can metabolize.

Learn more about Argania Spinosa Kernel Oil

This ingredient is a preservative and often used for it's anti-static properties. You'll most likely see this ingredient in hair conditioners.

It does not cause irritation or sensitization in leave-on products at 1-5%.

Emollient, Emulsifying, Emulsion Stabilising

Cetyl Alcohol is a fatty alcohol. Fatty Alcohols are most often used as an emollient or to thicken a product.

Its main roles are:

Though it has "alcohol" in the name, it is not related to denatured alcohol or ethyl alcohol.

The FDA allows products labeled "alcohol-free" to have fatty alcohols.

This ingredient may not be fungal acne safe. It is a primary fatty alcohol with a chain length above 12 carbons. A study from 2019 show Malassezia can feed on fatty alcohols in this range, so it may trigger fungal acne in those prone to it.

Learn more about Cetyl Alcohol
Emollient, Skin Conditioning

Cocos Nucifera Fruit Extract (coconut extract) is a water-soluble extract from coconut fruit.

It's a skin conditioning agent that helps keep the skin soft and hydrated. This ingredient is different from coconut oil with a totally different composition.

Direct research on this extract is limited and mostly comes from supplier safety dossiers:

Human testing found it to be non-irritating or sensitizing in a 50-subject occlusive patch test.

Real-world concentrations are very low: industry survey data puts it at 0.0007% to 0.02% in face and neck products, 0.0005% in moisturizers and cleansers, and up to 0.04% in hair conditioners.

Most human clinical skin research on coconut is on virgin coconut oil and not this extract. For example, a randomized double-blind trial found virgin coconut oil as effective and safe as mineral oil for mild to moderate xerosis with significant improvement in hydration and skin surface lipids. However, you can't transfer that to a water-based fruit extract at 0.01%.

There's no comedogenicity data for this specific ingredient; the "coconut clogs pores" reputation comes from coconut oil which scored high on the old rabbit ear assay.

That method tested pure ingredients on rabbit ears and later work showed the results translate inconsistently to human skin.

Some people still find it breaks them out. So if that's you, definitely trust your skin.

Learn more about Cocos Nucifera Fruit Extract
Perfuming

Coumarins are a group of substances found naturally in plants. There are over 1300 types of coumarins identified. It has a natural vanilla scent.

Coumarin is an identified EU known allergy, meaning it may cause an allergic reaction when applied to the skin.

In many countries, coumarin is banned as a food additive. However, it can be found in soaps, tobacco products, and some alcohol drinks.

Plants use coumarins as a chemical defense. Some plants that have coumarins include lavender, tonka beans, and yellow clovers.

Learn more about Coumarin

Ficus Carica Fruit Extract comes from the fruit known as the fig. Figs are rich in antioxidants and helps hydrate the skin.

Figs also contain fatty acids and Vitamins A, B1, and B2.

As a humectant, figs are able to draw moisture from the air to your skin. This helps keep your skin hydrated.

Learn more about Ficus Carica Fruit Extract
Humectant, Skin Conditioning, Skin Protecting

Glycerin (or glycerol) is a compound naturally found in your skin. It's a powerhouse humectant that pulls water into the stratum corneum.

Topically, glycerin does several things at once:

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.

Learn more about Glycerin

Leuconostoc/Radish Root Ferment Filtrate is a natural preservative. It comes from fermenting radish roots with a bacteria called leuconostoc. The trade name for this ingredient is Leucidal.

Leuconostoc comes from lactic acid.

This ingredient has antimicrobial properties and helps prevent the growth of bacteria in a product.

Leuconostoc is used to make the traditional Korean side-dish, kimchi. It is also used to make sourdough bread (both incredibly yummy foods).

Learn more about Leuconostoc/Radish Root Ferment Filtrate
Perfuming, Solvent

Limonene is the compound that gives citrus peel its smell.

In skincare, it shows up as a standalone fragrance ingredient or as a natural compound of citrus and other essential oils.

You'll typically see this ingredient used in very small amounts; anything above 0.001% in a leave-on product or 0.01% in a rinse-off has to be named on the label in the EU. The citrus oils that carry it sit around 0.5-1% in a finished formula.

Fresh limonene is a weak allergen; the real issue is that it slowly reacts with air and then breaks down from oxidation to create hydroperoxides (which are strong sensitizers). This is why suppliers are required to keep the peroxide value below 20 mmol.

Positive reactions in people being investigated for eczema vary:

It's worth skipping if you have a known fragrance allergy or a compromised barrier, but the risk is low for most people.

Older or long-opened products are also more likely to bother you than fresh ones due to oxidation.

Learn more about Limonene
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

Potassium Sorbate is a preservative used to prevent yeast and mold in products. It is commonly found in both cosmetic and food products.

This ingredient comes from potassium salt derived from sorbic acid. Sorbic acid is a natural antibiotic and effective against fungus.

Both potassium sorbate and sorbic acid can be found in baked goods, cheeses, dried meats, dried fruit, ice cream, pickles, wine, yogurt, and more.

You'll often find this ingredient used with other preservatives.

Learn more about Potassium Sorbate
Masking, Perfuming, Skin Conditioning

This ingredient is also known as castor oil. It is a skin conditioning ingredient.

The star component of castor oil is ricinoleic acid, an unusual fatty acid that makes up ~80-92% of its composition.

In skincare, it is an emollient that dries down to a solid film with water-binding properties. This helps keep skin hydrated and helps reduce transepidermal water loss (TEWL).

A 2026 dermatology review pulls together its broader uses:

Human clinical testing found this ingredient to be non-irritating and non-sensitizing.

Because castor oil contains fatty acids in the C11-24 range, this ingredient may not be fungal acne safe.

At this time, the literature does not support castor oil in regrowing hair. A 2022 systematic review found no strong evidence that it supports hair growth and only weak evidence that it improves hair shine.

Castor oil itself carries "perfuming" and "masking" function tags according to the official CosIng database. This is because of its mild odor and odor-dampening properties.

Learn more about Ricinus Communis Seed Oil
Skin Conditioning

This ingredient comes from fermenting yeast (Saccharomyces) with copper ions.

Skin Conditioning

Saccharomyces/Iron Ferment isn't fungal acne safe.

Saccharomyces/Magnesium Ferment isn't fungal acne safe.

Skin Conditioning

Saccharomyces/Silicon Ferment isn't fungal acne safe.

Skin Conditioning

Saccharomyces/Zinc Ferment isn't fungal acne safe.

Emollient, Skin Conditioning

Shea Butter Ethyl Esters is basically an "eco-designed" emollient ester derived from shea butter.

You can think of it like shea butter's lighter, more elegant sibling. The creating of this ingredient preserves shea butter's beneficial fatty acid profile while dramatically improving spreadability/skin feel.

This makes it a great choice for spray formulations, serums, and lightweight moisturizers where traditional shea butter would be too heavy.

It's rapidly absorbed on skin and provides an instant moisturizing effect and velvety after-feel.

These conditioning benefits trace back to shea's well-studied bioactive profile; shea is rich in antioxidants like tocopherols and contains stearic and oleic acids that support skin barrier health.

It also contains triterpene alcohols known to reduce inflammation, cinnamic acid esters with some UV-absorbing capacity, and lupeol that protects skin proteins.

Research backs up those triterpenes: a study isolating triterpene acetates and cinnamates from shea fat found all tested compounds showed anti-inflammatory activity in mice.

Fungal acne: Because this is an ethyl ester derived from shea's long-chain fatty acids (primarily stearic C18 and oleic C18), in vitro testing has shown the Malassezia species can grow in the presence of ethyl esters. This ingredient may not be fungal acne safe.

Learn more about Shea Butter Ethyl Esters
Masking, Preservative

Sodium Benzoate is a preservative. It's used in both cosmetic and food products to inhibit the growth of mold and bacteria. It is typically produced synthetically.

Both the US FDA and EU Health Committee have approved the use of sodium benzoate. In the US, levels of 0.1% (of the total product) are allowed.

Sodium benzoate works as a preservative by inhibiting the growth of bacteria inside of cells. It prevents the cell from fermenting a type of sugar using an enzyme called phosphofructokinase.

It is the salt of benzoic acid. Foods containing sodium benzoate include soda, salad dressings, condiments, fruit juices, wines, and snack foods.

Studies for using ascorbic acid and sodium benzoate in cosmetics are lacking, especially in skincare routines with multiple steps.

We always recommend speaking with a professional, such as a dermatologist, if you have any concerns.

Learn more about Sodium Benzoate
Antioxidant, Masking, Skin Conditioning

Tocopherol is a fat-soluble antioxidant known as Vitamin E.

You'll find this ingredient in the vast majority of skincare (for good reason). It works to neutralize free radicals, or unstable molecules generated by UV exposure, pollution, and other environmental stressors, before they can cause oxidative damage to your skin cells.

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.

Learn more about Tocopherol
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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