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Biologique Recherche Serum T.E.W.L.

Serum T.E.W.L.

Serum T.E.W.L. is an extremely active treatment that revitalizes and regenerates the skin. Eliminates tightness and the appearance of fine lines associated with dehydration. Prevents Trans Epidermal Water Loss. Great for those visiting or living in dry climates.
Uploaded by: rachelersted on

Biologique Recherche Serum T.E.W.L.
Ingredients explained

What-it-does: emollient

A clear, colorless to slightly yellowish oil that makes the skin nice and smooth (emollient), spreads easily on the skin and is marketed as a good alternative to volatile (does not absorb into the skin but rather evaporates from it) silicones like Cyclomethicone.

What-it-does: emollient, perfuming

A clear, slightly yellow, odorless oil  that's a very common, medium-spreading emollient. It makes the skin feel nice and smooth and works in a wide range of formulas.

Also-called: Sesame Oil | What-it-does: emollient | Irritancy: 0 | Comedogenicity: 1-3

A goldish to dark yellow emollient plant oil coming from Sesame seeds. Similar to many other plant oils, it contains high amounts of nourishing and moisturizing fatty acids (about 38% of oleic and 48% of linoleic acid) and is a nice oil to repair and regenerate dry skin. It is rapidly absorbed and gives the skin a soft and gentle feel.  

We don't have description for this ingredient yet.

Irritancy: 1 | Comedogenicity: 2-3

We don't have description for this ingredient yet.

Also-called: Cranberry Seed Oil | What-it-does: emollient

yellow-greenish oil coming from the seeds of Cranberry. Similar to other emollient plant oils, it is loaded with nice fatty acids. It contains a very balanced 1:1 ratio of anti-inflammatory omega-3 (aka linolenic acid) and barrier repairing omega-6 (aka linoleic acid) (30-38%), and also a decent amount of skin-nourishing omega-9, aka oleic acid. It also has high vitamin E content and significant antioxidant properties. 

Other than being a nice emollient plant oil, we also found a research showing that cranberry oil has wound-healing potential

Also-called: Sea Buckthorn Berry Oil;Hippophae Rhamnoides Fruit Oil | What-it-does: antioxidant, emollient

The oil coming from the pulp of the sea buckthorn berry. It has a pretty unique fatty acid composition: 65% is a combination of the rare Omega-7, aka palmitoleic acid and the more common palmitic acid. Fatty acids give the oil nice moisturizing and skin-protecting abilities. 

But that's not all the goodness of sea buckthorn oil. It contains antioxidant superstar, Vitamin E (in multiple forms), antioxidant (and orange color giving) pigments beta-carotene and lycopene, as well as skin-soothing and replenishing beta-sitosterol

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Btw, used undiluted, it will make your skin orange. 

All in all, a goodie emollient plant oil. 

We don't have description for this ingredient yet.

Also-called: Soybean Sterols | What-it-does: emollient

We don't have description for this ingredient yet.

Also-called: Jojoba Oil | What-it-does: emollient | Irritancy: 0 | Comedogenicity: 0-2

Jojoba is a drought resistant evergreen shrub native to South-western North America. It's known and grown for jojoba oil, the golden yellow liquid coming from the seeds (about 50% of the weight of the seeds will be oil).  

At first glance, it seems like your average emollient plant oil: it looks like an oil and it's nourishing and moisturizing to the skin but if we dig a bit deeper, it turns out that jojoba oil is really special and unique: technically - or rather chemically - it's not an oil but a wax ester (and calling it an oil is kind of sloppy). 

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So what the heck is a wax ester and why is that important anyway? Well, to understand what a wax ester is, you first have to know that oils are chemically triglycerides: one glycerin + three fatty acids attached to it. The fatty acids attached to the glycerin vary and thus we have many kinds of oils, but they are all triglycerides. Mother Nature created triglycerides to be easily hydrolyzed (be broken down to a glycerin + 3 fatty acid molecules) and oxidized (the fatty acid is broken down into small parts) - this happens basically when we eat fats or oils and our body generates energy from it.

Mother Nature also created wax esters but for a totally different purpose. Chemically, a wax ester is a fatty acid + a fatty alcohol, one long molecule. Wax esters are on the outer surface of several plant leaves to give them environmental protection. 25-30% of human sebum is also wax esters to give us people environmental protection. 

So being a wax ester results in a couple of unique properties: First, jojoba oil is extremely stable. Like crazy stable. Even if you heat it to 370 C (698 F) for 96 hours, it does not budge. (Many plant oils tend to go off pretty quickly). If you have some pure jojoba oil at home, you should be fine using it for years. 

Second, jojoba oil is the most similar to human sebum (both being wax esters), and the two are completely miscible. Acne.org has this not fully proven theory that thanks to this, jojoba might be able to "trick" the skin into thinking it has already produced enough sebum, so it might have "skin balancing" properties for oily skin.

Third, jojoba oil moisturizes the skin through a unique dual action: on the one hand, it mixes with sebum and forms a thin, non-greasy, semi-occlusive layer; on the other hand, it absorbs into the skin through pores and hair follicles then diffuses into the intercellular spaces of the outer layer of the skin to make it soft and supple.

On balance, the point is this: in contrast to real plant oils, wax esters were designed by Mother Nature to stay on the surface and form a protective, moisturizing barrier and jojoba oil being a wax ester is uniquely excellent at doing that.

Also-called: Vitaskin E | What-it-does: moisturizer/humectant

This long-named thing comes from the enzymatic biocatalysis of Raspberry Seed Oil and a Vitamin E derivative and is claimed by its manufacturer to be able to repair injured skin and restore a healthy barrier function (so that the skin is healthy and hydrated again). 

The manufacturer did some in-vivo (made on real people) studies to show that 1% Vitaskin-E cream did indeed decrease Trans-Epidermal-Water-Loss and reduced cracks and scales on dry lips better than placebo.

Tocopherol - goodie
Also-called: Vitamin E | What-it-does: antioxidant | Irritancy: 0-3 | Comedogenicity: 0-3
  • Primary fat-soluble antioxidant in our skin
  • Significant photoprotection against UVB rays
  • Vit C + Vit E work in synergy and provide great photoprotection
  • Has emollient properties
  • Easy to formulate, stable and relatively inexpensive
Read all the geeky details about Tocopherol here >>

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

Sunflower does not need a big intro as you probably use it in the kitchen as cooking oil, or you munch on the seeds as a healthy snack or you adore its big, beautiful yellow flower during the summer - or you do all of these and probably even more. And by even more  we mean putting it all over your face as sunflower oil is one of the most commonly used plant oils in skincare.

It’s a real oldie: expressed directly from the seeds, the oil is used not for hundreds but thousands of years. According to The National Sunflower Association, there is evidence that both the plant and its oil were used by American Indians in the area of Arizona and New Mexico about 3000 BC. Do the math: it's more than 5000 years – definitely an oldie.

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Our intro did get pretty big after all (sorry for that), so let's get to the point finally: sunflower oil - similar to other plant oils - is a great emollient that makes the skin smooth and nice and helps to keep it hydrated. It also protects the surface of the skin and enhances the damaged or irritated skin barrier. Leslie Bauman notes in Cosmetic Dermatology that one application of sunflower oil significantly speeds up the recovery of the skin barrier within an hour and sustains the results 5 hours after using it.

It's also loaded with fatty acids (mostly linoleic (50-74%)  and oleic (14-35%)). The unrefined version (be sure to use that on your skin!) is especially high in linoleic acid that is great even for acne-prone skin. Its comedogen index is 0, meaning that it's pretty much an all skin-type oil

Truth be told, there are many great plant oils and sunflower oil is definitely one of them.

Also-called: Prickly Pear Fruit Extract | What-it-does: soothing, moisturizer/humectant

The extract of Prickly Pear, a cactus that’s native to Mexico. Its main unique thing is that it can reduce the neurosensory irritation caused by the application of topical products such as retinoids (slow reaction) or alpha hydroxy acids (fast reaction). We have a shiny description about  Opuntia Ficus-Indica Extract here >>

Also-called: Rosemary Leaf Extract | What-it-does: antioxidant, soothing, antimicrobial/antibacterial

The extract coming from the lovely herb, rosemary. It contains lots of chemicals, including flavonoids, phenolic acids, and diterpenes. Its main active is rosmarinic acid, a potent antioxidant, and anti-inflammatory. It has also anti-bacterial, astringent and toning properties. 

The leaves contain a small amount of essential oil (1-2%) with fragrant components, so if you are allergic to fragrance, it might be better to avoid it. 

Also-called: Bitter Orange Flower Oil, Neroli Oil

The essential oil coming from the flowers of bitter orange (which is the sister of the sweet orange we all know and eat). It contains several fragrance components including linalool (around 30%) and limonene (around 10%) and has a lovely sweet smell

As it's an essential oil with lots of fragrant components, be careful with it if your skin is sensitive.  

Also-called: Ylang Ylang Essential Oil | What-it-does: perfuming

Sweet, exotic and floral, it’ no surprise that Ylang Ylang is a popular essential oil. It is coming from the yellow, fragrant flowers of the Cananga tree native to tropical Asia and, similar to other essential oils, it is a chemically complex mixture with several pros and cons. 

Unfortunately, these are a bit tricky to pin down as the composition varies largely depending on where it is sourced, how the oil is extracted and the grade of it that is used in the product, but we’ll do our best!

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Let’s start with the easy stuff.  The main components are fragrant molecules, including super common linalool (1-19%), benzyl benzoate (2-10%) and several others adding up to a max amount of 37.6% of EU sensitizers. The most expensive Extra grade is the most fragrant (has more benzyl acetate and cresyl methyl ether) and is used in high-end perfumes, while the First and Second grades are less fragrant, and used mainly in cosmetics.   

Other than smelling nice and making cosmetic formulas also smell nice, Ylang Ylang might have some antimicrobial and antioxidant benefits and also works as an insect repellent. Its nice smell is also commonly known as being relaxing and calming (also backed up by a few recent studies), but it is an aromatherapy use case (when inhaled) so this probably does not count much skincare-wise. 

On the other hand, the nice smell also means allergen fragrant components and 37.6% of EU sensitizers counts as quite high and the oil is considered to have high skin sensitization potential. It is a good idea to avoid if your skin is sensitive.

Cholesterol - goodie
What-it-does: skin-identical ingredient, emollient | Irritancy: 0 | Comedogenicity: 0

It's one of the important lipids that can be found naturally in the outer layer of the skin. About 25% of the goopy stuff between our skin cells consists of cholesterol. Together with ceramides and fatty acids, they play a vital role in having a healthy skin barrier and keeping the skin hydrated. 

Apart from being an important skin-identical ingredient, it's also an emollient and stabilizer

What-it-does: viscosity controlling

We don't have description for this ingredient yet.

What-it-does: perfuming

We don't have description for this ingredient yet.

What-it-does: perfuming

It’s a common fragrance ingredient that has a light floral smell.  It’s one of the “EU 26 fragrances” that has to be labelled separately (and cannot be simply included in the term “fragrance/perfume” on the label) because of allergen potential. Best to avoid if your skin is sensitive.

A common fragrance ingredient that has a faint sweet balsamic smell. It can also be a solvent and can fight against microbes and insects very well.

It's one of the “EU 26 fragrances” that has to be labelled separately because of allergen potential. Best to avoid if your skin is sensitive.

Limonene - icky
What-it-does: perfuming, solvent, deodorant

A super common and cheap fragrance ingredient. It's in many plants, e.g. rosemary, eucalyptus, lavender, lemongrass, peppermint and it's the main component (about 50-90%) of the peel oil of citrus fruits.

It does smell nice but the problem is that it oxidizes on air exposure and the resulting stuff is not good for the skin. Oxidized limonene can cause allergic contact dermatitis and counts as a frequent skin sensitizer

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Limonene's nr1 function is definitely being a fragrance component, but there are several studies showing that it's also a penetration enhancer, mainly for oil-loving components.

All in all, limonene has some pros and cons, but - especially if your skin is sensitive - the cons probably outweigh the pros.  

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

With a sweet, light and floral scent, Farnesol is a popular fragrancing ingredient to make your cosmetics that bit nicer to use. It starts its life as a colorless liquid that can either be synthetically created or extracted from loads of plants like citronella, neroli, ylang-ylang, and tuberose.

The reason we list it as icky is because Farnesol is one of the “EU 26 fragrances” that has to be labeled separately (and cannot be simply included in the term “fragrance/perfume” on the label) because of allergen potential, so it is best avoided if you have super sensitive skin.

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.

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. 

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what‑it‑does emollient | perfuming
A clear, slightly yellow, odorless oil  that's a very common, medium-spreading emollient. It makes the skin feel nice and smooth and works in a wide range of formulas.
what‑it‑does emollient
irritancy, com. 0, 1-3
Emollient plant oil coming from the seeds of Sesame. Contains high amounts of nourishing and moisturizing fatty acids (about 38% of oleic 48% of linoleic acid). [more]
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irritancy, com. 1, 2-3
what‑it‑does emollient
A yellow-greenish oil coming from the seeds of Cranberry. Similar to other emollient plant oils, it is loaded with nice fatty acids. It contains a very balanced 1:1 ratio of anti-inflammatory omega-3 (aka linolenic acid) and barrier repairing omega-6 (aka linoleic acid) (30-38%), and also a decent amount of skin-nourishing omega-9, aka oleic acid. [more]
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Sea buckthorn berry oil - contains rare omega-7 fatty acid, antioxidants, and skin-soothing plant sterols. A nice moisturising and skin protecting oil. [more]
what‑it‑does emollient
what‑it‑does emollient
irritancy, com. 0, 0-2
Jojoba oil - a wax ester (chemically not a real oil), that's very similar to human sebum. It's uniquely excellent at helping the skin with its protective barrier and helping it to stay moisturized. [more]
what‑it‑does moisturizer/humectant
Comes from the enzymatic biocatalysis of Raspberry Seed Oil and a Vitamin E derivative and is claimed to be able to repair injured skin and restore a healthy barrier function. [more]
what‑it‑does antioxidant
irritancy, com. 0-3, 0-3
Pure Vitamin E. Great antioxidant that gives significant photoprotection against UVB rays. Works in synergy with Vitamin C. [more]
what‑it‑does emollient
irritancy, com. 0, 0
Sunflower Oil - it's a great emollient that protects & enhances the skin barrier. [more]
what‑it‑does soothing | moisturizer/humectant
The extract of Prickly Pear, a cactus that’s native to Mexico. Its main unique thing is that it can reduce the neurosensory irritation caused by the application of topical products such as retinoids (slow reaction) or alpha hydroxy acids (fast reaction). [more]
what‑it‑does antioxidant | soothing | antimicrobial/antibacterial
Rosemary leaf extract - Its main active is rosmarinic acid, a potent antioxidant, and anti-inflammatory. It has also anti-bacterial, astringent and toning properties. [more]
The essential oil coming from the flowers of bitter orange. Contains fragrant components that give it a nice sweet smell. [more]
what‑it‑does perfuming
Sweet, exotic and floral, it’ no surprise that Ylang Ylang is a popular essential oil. It is coming from the yellow, fragrant flowers of the Cananga tree native to tropical Asia and, similar to other essential oils, it is a chemically complex mixture with several pros and cons. Unfortunately, these are a bit tricky to pin down as the composition varies largely depending on where it is so [more]
what‑it‑does skin-identical ingredient | emollient
irritancy, com. 0, 0
It's one of the important lipids that can be found naturally in the outer layer of the skin. About 25% of the goopy stuff between our skin cells consists of cholesterol. [more]
what‑it‑does viscosity controlling
what‑it‑does perfuming
what‑it‑does perfuming
It’s a common fragrance ingredient that has a light floral smell.  It’s one of the “EU 26 fragrances” that has to be labelled separately (and cannot be simply included in the term “fragrance/perfume” [more]
what‑it‑does solvent | perfuming | antimicrobial/antibacterial
A common fragrance ingredient that has a faint sweet balsamic smell. It can also be a solvent and can fight against microbes and insects very well. One of the “EU 26 fragrances” that has to be labelled separately because of allergen potential.
what‑it‑does perfuming | solvent
A super common fragrance ingredient found naturally in many plants including citrus peel oils, rosemary or lavender. It autoxidizes on air exposure and counts as a common skin sensitizer. [more]
what‑it‑does perfuming
With a sweet, light and floral scent, Farnesol is a popular fragrancing ingredient to make your cosmetics that bit nicer to use. It starts its life as a colorless liquid that can either be synthetically created or extracted from loads of plants like citronella, neroli, ylang-ylang, and tuberose.The reason we list it as icky is because Farnesol is one of the “ [more]
what‑it‑does perfuming
A common fragrance ingredient that smells like rose and can be found in rose oil. [more]
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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]