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Kerastase Resistance Masque Therapiste

Resistance Masque Therapiste

Repairing hair mask for over processed hair.
Uploaded by: cmccall on 04/10/2019

Kerastase Resistance Masque Therapiste
Ingredients explained

Also-called: Aqua;Water | What-it-does: solvent

Good old water, aka H2O. The most common skincare ingredient of all. You can usually find it right in the very first spot of the ingredient list, meaning it’s the biggest thing out of all the stuff that makes up the product. 

It’s mainly a solvent for ingredients that do not like to dissolve in oils but rather in water. 

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Once inside the skin, it hydrates, but not from the outside - putting pure water on the skin (hello long baths!) is drying. 

One more thing: the water used in cosmetics is purified and deionized (it means that almost all of the mineral ions inside it is removed). Like this, the products can stay more stable over time. 

What-it-does: emollient, viscosity controlling | Irritancy: 1 | Comedogenicity: 2

An extremely common multitasker ingredient that gives your skin a nice soft feel (emollient) and gives body to creams and lotions. It also helps to stabilize oil-water mixes (emulsions), though it does not function as an emulsifier in itself. Its typical use level in most cream type formulas is 2-3%.  

It’s a so-called fatty alcohol, a mix of cetyl and stearyl alcohol, other two emollient fatty alcohols.  Though chemically speaking, it is alcohol (as in, it has an -OH group in its molecule), its properties are totally different from the properties of low molecular weight or drying alcohols such as denat. alcohol. Fatty alcohols have a long oil-soluble (and thus emollient) tail part that makes them absolutely non-drying and non-irritating and are totally ok for the skin.

Also-called: Mineral Oil;Paraffinum Liquidum | What-it-does: emollient | Irritancy: 0 | Comedogenicity: 0-2

The famous or maybe rather infamous mineral oil. The clear oily liquid that is the "cheap by-product" of refining crude oil and the one that gets a lot of heat for its poor provenance. It is a very controversial ingredient with pros and cons and plenty of myths around it. So let us see them:  

The pros of mineral oil
Trust us, if something is used for more than 100 years in cosmetic products, it has advantages. Chemically speaking, cosmetic grade mineral oil is a complex mixture of highly refined saturated hydrocarbons with C15-50 chain length. It is not merely a "by-product" but rather a specifically isolated part of petroleum that is very pure and inert.

It is a great emollient and moisturizer working mainly by occlusivity. Occlusivity is one of the basic mechanisms of how moisturizers work and it means that mineral oil sits on top of the skin and hinders so-called trans-epidermal water loss, i.e water evaporating out of your skin. When compared to heavy-duty plant oil, extra virgin coconut oil, the two of them were equally efficient and safe as moisturizers in treating xerosis, a skin condition connected to very dry skin.

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The other thing that mineral oil is really good at is being non-irritating to the skin. The chemical composition of plant oils is more complex with many more possible allergens or irritating components, while mineral oil is simple, pure and sensitivity to it is extremely rare. If you check out the classic French pharmacy brands and their moisturizers for the most sensitive, allergy prone skin, they usually contain mineral oil. This is no coincidence. 

The cons of mineral oil
The pros of mineral oil can be interpreted as cons if we look at them from another perspective. Not penetrating the skin but mostly just sitting on top of it and not containing biologically active components, like nice fatty acids and vitamins mean that mineral oil does not "nourish" the skin in the way plant oils do. Mineral oil does not give the skin any extra goodness, it is simply a non-irritating moisturizer working mainly by occlusivity. 

The myths around mineral oil
Badmouthing mineral oil is a favorite sport of many, it is a cheap material and being connected to petrolatum makes it fairly easy to demonize. 

While it is true that industrial grade mineral oil contains carcinogenic components (so-called polycyclic compounds), these are completely removed from cosmetic and food grade mineral oil and there is no scientific data showing that the pure, cosmetic grade version is carcinogenic.

What is more, in terms of the general health effects of mineral oils used in cosmetics, a 2017 study reviewed the data on their skin penetration and concluded that "the cosmetic use of mineral oils and waxes does not present a risk to consumers due to a lack of systemic exposure."  

Another super common myth surrounding mineral oil is that it is comedogenic. A 2005 study titled "Is mineral oil comedogenic?" examined this very question and guess what happened? The study concluded that  "based on the animal and human data reported, along with the AAD recommendation, it would appear reasonable to conclude that mineral oil is noncomedogenic in humans.

Overall, we feel that the scaremongering around mineral oil is not justified. For dry and super-sensitive skin types it is a great option. However, if you do not like its origin or its heavy feeling or anything else about it, avoiding it has never been easier. Mineral oil has such a bad reputation nowadays that cosmetic companies hardly dare to use it anymore. 

Also-called: Babassu Oil | What-it-does: emollient | Irritancy: 0 | Comedogenicity: 1

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

Also-called: Fragrance, Parfum | What-it-does: perfuming

Exactly what it sounds: nice smelling stuff put into cosmetic products so that the end product also smells nice. Fragrance in the US and parfum in the EU is a generic term on the ingredient list that is made up of 30 to 50 chemicals on average (but it can have as much as 200 components!). 

If you are someone who likes to know what you put on your face than fragrance is not your best friend - no way to know what’s really in it.  

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Also, if your skin is sensitive, fragrance is again not your best friend. It’s the number one cause of contact allergy to cosmetics. It’s definitely a smart thing to avoid with sensitive skin (and fragrance of any type - natural is just as allergic as synthetic, if not worse!). 

What-it-does: emollient

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

It’s a handy multi-tasking ingredient that gives the skin a nice, soft feel. At the same time, it also boosts the effectiveness of other preservatives, such as the nowadays super commonly used phenoxyethanol

The blend of these two (caprylyl glycol + phenoxyethanol) is called Optiphen, which not only helps to keep your cosmetics free from nasty things for a long time but also gives a good feel to the finished product. It's a popular duo.

Linalool - icky
What-it-does: perfuming, deodorant

Linalool is a super common fragrance ingredient. It’s kind of everywhere - both in plants and in cosmetic products. It’s part of 200 natural oils including lavender, ylang-ylang, bergamot, jasmine, geranium and it can be found in 90-95% of prestige perfumes on the market. 

The problem with linalool is, that just like limonene it oxidises on air exposure and becomes allergenic. That’s why a product containing linalool that has been opened for several months is more likely to be allergenic than a fresh one.

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A study made in the UK with 483 people tested the allergic reaction to 3% oxidised linalool and 2.3% had positive test results. 

Citric Acid - goodie
What-it-does: exfoliant, buffering

Citric acid comes from citrus fruits and is an AHA. If these magic three letters don’t tell you anything, click here and read our detailed description on glycolic acid, the most famous AHA. 

So citric acid is an exfoliant, that can - just like other AHAs - gently lift off the dead skin cells of your skin and make it more smooth and fresh. 

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There is also some research showing that citric acid with regular use (think three months and 20% concentration) can help sun-damaged skin, increase skin thickness and some nice hydrating things called glycosaminoglycans in the skin. 

But according to a comparative study done in 1995, citric acid has less skin improving magic properties than glycolic or lactic acid. Probably that’s why citric acid is usually not used as an exfoliant but more as a helper ingredient in small amounts to adjust the pH of a formulation. 

We don't have description for this ingredient yet.

What-it-does: perfuming

Citronellol is a very common fragrance ingredient with a nice rose-like odor. In the UK, it’s actually the third most often listed perfume on the ingredient lists. 

It can be naturally found in geranium oil (about 30%) or rose oil (about 25%). 

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As with all fragrance ingredients, citronellol can also cause allergic contact dermatitis and should be avoided if you have perfume allergy. In a 2001 worldwide study with 178 people with known sensitization to fragrances citronellol tested positive in 5.6% of the cases.

There is no known anti-aging or positive skin benefits of the ingredient. It’s in our products to make it smell nice. 

Also-called: Butylated Hydroxy Toluene | What-it-does: antioxidant, preservative

It's the acronym for Butylated Hydroxy Toluene. It's a common synthetic antioxidant that's used as a preservative.

There is some controversy around BHT. It's not a new ingredient, it has been used both as a food and cosmetics additive since the 1970s. Plenty of studies tried to examine if it's a carcinogen or not. This Truth in Aging article details the situation and also writes that all these studies examine BHT when taken orally.

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As for cosmetics, the CIR (Cosmetic Ingredient Review) concluded that the amount of BHT used in cosmetic products is low (usually around 0.01-0.1%),  it does not penetrate skin far enough to be absorbed into the bloodstream and it is safe to use in cosmetics.

Glycine - goodie

A non-essential amino acid (the building blocks of skin proteins, like collagen or elastin), that the body can produce itself, but its production decreases with age. When you put it all over your face, it works as a moisturizer and maybe more. 

According to great skincare blog Futurederm, glycine might help with wound healing and tissue repair and when used together with other amino acids, leucine and proline it might improve wrinkles

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BTW, it's also a building block of a bunch of important and famous peptides, including copper-tripeptide-1, palmitoyl tripeptide-1 or palmitoyl hexapeptide-12.

Arginine - goodie

A semi-essential (infants cannot synthesize it, but adults can) amino acid that is one of the primary building blocks of hair keratin and skin collagen. It's a natural moisturizing factor, a skin hydrator and might also help to speed up wound healing

Arginine usually has a positive charge (cationic) that makes it substantive to skin and hair (those are more negatively charged surfaces) and an excellent film former.  Thanks to the positive charge, it also creates a complex with AHAs (AHAs like to lose a hydrogen ion and be negatively charged, so the positive and the negative ions attract each other) that causes a "time-release AHA effect" and reduces the irritation associated with AHAs

Proline - goodie

A non-essential amino acid (meaning that our body can produce it) that's also one of the major building blocks of collagen. According to the Futurederm blog, it might be able to improve wrinkles when combined with other amino acids, glycine and leucine

We don't have description for this ingredient yet.

What-it-does: moisturizer/humectant

Glutamic acid is a little molecule and non-essential (our body can synthesize it) amino acid with the important job of being a neurotransmitter in the human body meaning that it helps your nervous system work correctly. 

As for what it's doing in cosmetics, Glutamic acids' main thing (similar to other amino acids) is being a humectant moisturizer and skin-conditioning agent (sidenote: if you attach lots of glutamic acid molecules, you get polyglutamic acid that is claimed to be a better than hyaluronic acid humectant). It also seems to affect skin barrier repair, however, it is not clear-cut in which direction.

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The complication is that glutamic acid has two distinct forms, L-glutamic acid and D-glutamic acid, that are the mirror images of each other (think of it like your left and right hand). Studies show that a topical application of L-glutamic acid on damaged skin delayed skin repair, while D-glutamic acid application sped up skin repair. As both forms are used by the industry, it is a bit uncertain what you are getting with just glutamic acid on the ingredient list (but if it is a  Shiseido group product, it is probably the goodie D-form :)). 

Other than that, Glutamic acid can also be used as a pH adjuster and can be processed via biological pathways into pyrrolidone carboxylic acid, the sodium salt of which is a goodie and one of your skin’s natural moisturizing factors.

Geraniol - icky
What-it-does: perfuming

Geraniol is a common fragrance ingredient. It smells like rose and can be found in rose oil or in small quantities in geranium, lemon and many other essential oils. 

Just like other similar fragrance ingredients (like linalool and limonene) geraniol also oxidises on air exposure and becomes allergenic. Best to avoid if you have sensitive skin.

Serine - goodie

Serine is an amino acid that most often comes to the formula as part of a moisturizing complex. It's a non-essential amino acid (meaning that our body can synthesize it) and serves as a water-binding ingredient.

In general, amino acids are great skincare ingredients that play an important role in proper skin hydration but there is not much info out there about what specifically serine can do for the skin.

We don't have description for this ingredient yet.

It's one of those things that help your cosmetics not to go wrong too soon, aka a preservative. It can be naturally found in fruits and teas but can also be made synthetically.

No matter the origin, in small amounts (up to 1%) it’s a nice, gentle preservative. Has to be combined with some other nice preservatives, like potassium sorbate to be broad spectrum enough.  

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In high amounts, it can be a skin irritant, but don’t worry, it’s never used in high amounts.

We don't have description for this ingredient yet.

What-it-does: perfuming

We don't have description for this ingredient yet.

Glycerin - superstar
Also-called: Glycerol | What-it-does: skin-identical ingredient, moisturizer/humectant | Irritancy: 0 | Comedogenicity: 0
  • A natural moisturizer that’s also in our skin
  • A super common, safe, effective and cheap molecule used for more than 50 years
  • Not only a simple moisturizer but knows much more: keeps the skin lipids between our skin cells in a healthy (liquid crystal) state, protects against irritation, helps to restore barrier
  • Effective from as low as 3% with even more benefits at higher concentrations up to 20-40% (around 10% is a good usability-effectiveness sweet spot)
  • High-glycerin moisturizers are awesome for treating severely dry skin
Read all the geeky details about Glycerin here >>

Trehalose - goodie
What-it-does: moisturizer/humectant

A type of sugar that has water-binding properties and helps to keep your skin hydrated

We don't have description for this ingredient yet.

What-it-does: emollient

We don't have description for this ingredient yet.

You may also want to take a look at...

what‑it‑does solvent
Normal (well kind of - it's purified and deionized) water. Usually the main solvent in cosmetic products. [more]
what‑it‑does emollient | viscosity controlling
irritancy, com. 1, 2
A super common multitasker ingredient that gives your skin a nice soft feel (emollient) and gives body to creams. [more]
what‑it‑does emollient
irritancy, com. 0, 0-2
A clear, oily liquid that comes from refining crude oil. Even though it is a highly controversial ingredient, the scientific consensus is that it is a safe, non-irritating and effective emollient and moisturizer working mainly by occlusivity. [more]
what‑it‑does emollient
irritancy, com. 0, 1
what‑it‑does perfuming
The generic term for nice smelling stuff put into cosmetic products so that the end product also smells nice. It is made up of 30 to 50 chemicals on average. [more]
what‑it‑does emollient
what‑it‑does antimicrobial/antibacterial | emulsifying | preservative | surfactant/cleansing
what‑it‑does moisturizer/humectant | emollient
A handy multi-tasking ingredient that gives the skin a nice, soft feel and also boosts the effectiveness of other preservatives. [more]
what‑it‑does perfuming
A super common fragrance ingredient that can be found among others in lavender, ylang-ylang, bergamot or jasmine. The downside of it is that it oxidises on air exposure and might become allergenic. [more]
what‑it‑does exfoliant | buffering
An AHA that comes from citrus fruits. It is usually used as a helper ingredient to adjust the pH of the formula. [more]
what‑it‑does perfuming
A common fragrance ingredient with a nice rose-like smell. [more]
what‑it‑does antioxidant | preservative
It's the acronym for Butylated Hydroxy Toluene. It's a common synthetic antioxidant that's used as a preservative.There is some controversy around BHT. [more]
what‑it‑does skin-identical ingredient
An amino acid (the building blocks of skin proteins, like collagen) that hydrates the skin and might help wound healing and improve wrinkles. [more]
what‑it‑does skin-identical ingredient
An amino acid that is one of the primary building blocks of hair keratin and skin collagen. It's a natural moisturizing factor and might also help to speed up wound healing.  [more]
what‑it‑does skin-identical ingredient
A non-essential amino acid (meaning that our body can produce it) that might be able to improve wrinkles combined with other amino acids, glycine and leucine. [more]
what‑it‑does moisturizer/humectant
Glutamic acid is a little molecule and non-essential (our body can synthesize it) amino acid with the important job of being a neurotransmitter in the human body meaning that it helps your nervous system work correctly.  As for what it's doing in cosmetics, Glutamic acids' main thing (similar to other amino acids) is being a humectant moisturizer and skin-conditioning [more]
what‑it‑does perfuming
A common fragrance ingredient that smells like rose and can be found in rose oil. [more]
what‑it‑does skin-identical ingredient
Serine is an amino acid that most often comes to the formula as part of a moisturizing complex. It's a non-essential amino acid (meaning that our body can synthesize it) and serves as a water-binding ingredient.In general, amino acids are great skincare ingredients that play an important role in proper skin hydration but there is not much info out there about what specifically serine can d [more]
what‑it‑does preservative | perfuming | solvent | viscosity controlling
It's one of those things that help your cosmetics not to go wrong too soon, aka a preservative. It can be naturally found in fruits and teas but can also be made synthetically. No matter the origin, in small amounts (up to 1%) it’s a nice, gentle preservative. [more]
what‑it‑does perfuming
what‑it‑does skin-identical ingredient | moisturizer/humectant
irritancy, com. 0, 0
A real oldie but a goodie. Great natural moisturizer and skin-identical ingredient that plays an important role in skin hydration and general skin health. [more]
what‑it‑does moisturizer/humectant
A type of sugar that has water-binding properties and helps to keep your skin hydrated. 
what‑it‑does emollient