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Jacques Janine Molecular Thermoactive Leave-in J18

Molecular Thermoactive Leave-in J18

J18 molecular leave-in was specially developed for damaged and chemically treated hair. It acts on the deepest layers of the hair fiber, restructuring the strands in just 4 minutes. It reconnects broken polypeptide chains, in addition to restoring the strength and elasticity of the hair.
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Jacques Janine Molecular Thermoactive Leave-in J18
Ingredients explained

Also-called: 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. 

What-it-does: emollient, viscosity controlling, emulsion stabilising, emulsifying, surfactant/cleansing | Irritancy: 2 | Comedogenicity: 2

A handy multi-tasker, white to light yellowish oil-loving wax that works very well in oil-in-water emulsions.  It makes your skin feel nice and smooth (emollient),  stabilizes oil-water mixes and gives body to them.

Oh, and one more thing: it's a so-called fatty alcohol - the good, emollient type of alcohol that is non-drying and non-irritating. It is often mixed with fellow fatty alcohol, Cetyl Alcohol, and the mixture is called Cetearyl Alcohol in the ingredient list. 

What-it-does: moisturizer/humectant, solvent | Irritancy: 0 | Comedogenicity: 0
  • It's a helper ingredient that improves the freeze-thaw stability of products
  • It's also a solvent, humectant and to some extent a penetration enhancer
  • It has a bad reputation among natural cosmetics advocates but cosmetic scientists and toxicology experts do not agree (read more in the geeky details section)
Read all the geeky details about Propylene Glycol here >>

What-it-does: preservative

We don't have description for this ingredient yet.

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

A so-called fatty (the good, non-drying kind of) alcohol that does all kinds of things in a skincare product: it makes your skin feel smooth and nice (emollient), helps to thicken up products and also helps water and oil to blend (emulsifier). Can be derived from coconut or palm kernel oil.

Parfum - icky
Also-called: Fragrance, Parfum;Parfum/Fragrance | 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 then fragrance is not your best friend - there's no way to know what’s really in it.  

What-it-does: emollient | Irritancy: 1 | Comedogenicity: 3-4

A clear, colorless emollient ester (oily liquid from isopropyl alcohol + palmitic acid) that makes the skin nice and smooth. It has very good spreading properties and gives a silky touch to the products.

What-it-does: emollient | Irritancy: 2 | Comedogenicity: 4

We don't have description for this ingredient yet.

What-it-does: preservative

It’s pretty much the current IT-preservative. It’s safe and gentle, but even more importantly, it’s not a feared-by-everyone-mostly-without-scientific-reason paraben.

It’s not something new: it was introduced around 1950 and today it can be used up to 1% worldwide. It can be found in nature - in green tea - but the version used in cosmetics is synthetic. 

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

What-it-does: astringent

We don't have description for this ingredient yet.

What-it-does: solvent, viscosity controlling, perfuming | Irritancy: 0 | Comedogenicity: 0

We don't have description for this ingredient yet.

What-it-does: perfuming

We don't have description for this ingredient yet.

Panthenol - goodie
Also-called: Pro-Vitamin B5 | What-it-does: soothing, moisturizer/humectant | Irritancy: 0 | Comedogenicity: 0

An easy-to-formulate, commonly used, nice to have ingredient that’s also called pro-vitamin B5. As you might guess from the “pro” part, it’s a precursor to vitamin B5 (whose fancy name is pantothenic acid). 

Its main job in skincare products is to moisturise the skin. It’s a humectant meaning that it can help the skin to attract water and then hold onto it. There is also research showing that panthenol can help our skin to produce more lovely lipids that are important for a strong and healthy skin barrier. 

What-it-does: moisturizer/humectant

A chemically chopped up version of wheat protein that consists mainly of amino acids (the building blocks), peptides (a couple of amino acids together), and proteins (lots of amino acids together). 

It has moisturizing and film-forming properties and  might be able to counteract the irritating effects of cleansing agents in cleansers and shampoos. It can also condition and repair damaged hair leaving it soft, silky and smooth.

Also-called: Vitamin E Acetate | What-it-does: antioxidant | Irritancy: 0 | Comedogenicity: 0

It’s the most commonly used version of pure vitamin E in cosmetics. You can read all about the pure form here. This one is the so-called esterified version. 

According to famous dermatologist, Leslie Baumann while tocopheryl acetate is more stable and has a longer shelf life, it’s also more poorly absorbed by the skin and may not have the same awesome photoprotective effects as pure Vit E. 

A glycerin-derived gentle cleansing agent that is described as being skin and eye-friendly, and not leaving the skin dry or tight. It's also used as a co-emulsifier or solubilizer that helps to blend small amounts of oily things into water-based products. 

What-it-does: emollient

We don't have description for this ingredient yet.

Lactic Acid - superstar
  • It’s the second most researched AHA after glycolic acid
  • It gently lifts off dead skin cells to reveal newer, fresher, smoother skin
  • It also has amazing skin hydrating properties
  • In higher concentration (10% and up) it improves skin firmness, thickness and wrinkles
  • Choose a product where you know the concentration and pH value because these two greatly influence effectiveness
  • Don’t forget to use your sunscreen (in any case but especially so next to an AHA product)
Read all the geeky details about Lactic Acid here >>

We don't have description for this ingredient yet.

What-it-does: moisturizer/humectant

We don't have description for this ingredient yet.

Benzotriazolyl Dodecyl P-Cresol is a broadband UV absorber used to stabilize products in transparent packaging. It protects sensitive ingredients such as colors, fragrances, or natural extracts from photooxidative degradation. The recommended usage rate is 0.01% - 0.1%.

What-it-does: perfuming

A common fragrance ingredient that smells like jasmine. It is one of the “EU 26 fragrances” that has to be labelled separately because of allergen potential. Best to avoid if your skin is sensitive.

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.

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.  

Alanine - goodie

A non-essential amino acid (a building block of skin proteins like collagen or elastin) that hydrates the skin.

We don't have description for this ingredient yet.

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.

What-it-does: surfactant/cleansing, emulsifying, perfuming | Irritancy: 3 | Comedogenicity: 1

We don't have description for this ingredient yet.

What-it-does: preservative

A controversial preservative that has formaldehyde-releasing properties. It works great against bacteria and also has mild fungicide abilities. 

Cosmetic chemist, Colin wrote a great article about formaldehyde and DMDM Hydantoin.  He writes that formaldehyde is the perfect example of "the dose makes the poison" principle. It's a natural stuff that can also be found in fresh fruits and vegetables, and eating it in tiny amounts is totally ok. However, in larger amounts (according to Wikipedia 30 mL of a solution containing 37% formaldehyde) it's deadly. 

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

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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 | emulsifying | surfactant/cleansing
irritancy, com. 2, 2
A handy multi-tasker, white to light yellowish oil-loving wax that works very well in oil-in-water emulsions.  It makes your skin feel nice and smooth (emollient),  stabilizes oil-water mixes and gives body to them.Oh, and one more thing: [more]
what‑it‑does moisturizer/humectant | solvent
irritancy, com. 0, 0
A common glycol that improves the freeze-thaw stability of products. It's also a solvent, humectant and to some extent a penetration enhancer. [more]
what‑it‑does preservative
what‑it‑does emollient | viscosity controlling
irritancy, com. 2, 2
A fatty (the good, non-drying kind of) alcohol that makes your skin feel smooth and nice (emollient), helps to thicken up products and also helps water and oil to blend (emulsifier).
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
irritancy, com. 1, 3-4
A clear, colorless emollient ester (oily liquid) that makes the skin nice and smooth. [more]
what‑it‑does emollient
irritancy, com. 2, 4
what‑it‑does preservative
Pretty much the current IT-preservative. It’s safe and gentle, and can be used up to 1% worldwide. [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 solvent | viscosity controlling | perfuming
irritancy, com. 0, 0
what‑it‑does perfuming
what‑it‑does soothing | moisturizer/humectant
irritancy, com. 0, 0
Pro-Vitamin B5 is a goodie that moisturises the skin, has anti-inflammatory, skin protecting and wound healing properties. [more]
what‑it‑does moisturizer/humectant
A chemically chopped up version of wheat protein with moisturizing and film-forming properties. [more]
what‑it‑does antioxidant
irritancy, com. 0, 0
A form of vitamin E that works as an antioxidant. Compared to the pure form it's more stable, has longer shelf life, but it's also more poorly absorbed by the skin. [more]
what‑it‑does surfactant/cleansing | emulsifying
A glycerin-derived gentle cleansing agent that is described as being skin and eye-friendly, and not leaving the skin dry or tight. Also used as a co-emulsifier.
what‑it‑does emollient
what‑it‑does exfoliant | moisturizer/humectant | buffering
A superstar AHA that not only exfoliates skin but is also a very good moisturizer. In higher concentration (10% and up) it can even improve skin firmness, thickness, and wrinkles. [more]
what‑it‑does moisturizer/humectant
Benzotriazolyl Dodecyl P-Cresol is a broadband UV absorber used to stabilize products in transparent packaging. It protects sensitive ingredients such as colors, fragrances, or natural extracts from photooxidative degradation. [more]
what‑it‑does perfuming
A common fragrance ingredient that smells like jasmine. It is one of the “EU 26 fragrances” that has to be labelled separately because of allergen potential. [more]
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 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 skin-identical ingredient
A non-essential amino acid (a building block of skin proteins like collagen or elastin) that hydrates the skin.
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 surfactant/cleansing | emulsifying | perfuming
irritancy, com. 3, 1
what‑it‑does preservative
A controversial preservative that has formaldehyde-releasing properties. It works great against bacteria and also has mild fungicide abilities.  [more]