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La Roche-Posay Rosaliac Ar Intense Serum

Rosaliac Ar Intense Serum

VISIBLE REDNESS REDUCING SERUM: This intensive daily formula helps to visibly reduce facial redness. It is enriched with ambophenol, a powerful natural extract, soothing neurosensine, and light reflectors.
Uploaded by: evaschumacher on 06/04/2019

La Roche-Posay Rosaliac Ar Intense Serum
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. 

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 >>

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

A mild, emollient liquid that can improve product spreadability and gives a silky and non-oily feel to the cosmetic products. 

What-it-does: moisturizer/humectant, solvent | Irritancy: 0 | Comedogenicity: 1

Butylene glycol, or let’s just call it BG, is a multi-tasking colorless, syrupy liquid. It’s a great pick for creating a nice feeling product.  

BG’s main job is usually to be a solvent for the other ingredients. Other tasks include helping the product to absorb faster and deeper into the skin (penetration enhancer), making the product spread nicely over the skin (slip agent), and attracting water (humectant) into the skin.

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It’s an ingredient whose safety hasn’t been questioned so far by anyone (at least not that we know about). BG is approved by Ecocert and is also used enthusiastically in natural products. BTW, it’s also a food additive. 

A multi-functional, silky feeling helper ingredient that can do quite many things. It's used as an emulsion stabilizer, solvent and a broad spectrum antimicrobial. According to manufacturer info, it's also a moisturizer and helps to make the product feel great on the skin. It works synergistically with preservatives and helps to improve water-resistance of sunscreens. 

What-it-does: emulsifying | Irritancy: 0 | Comedogenicity: 0

It's a common little helper ingredient that helps water and oil to mix together. Also, it can help to increase the solubility of some other ingredients in the formula. 

We don't have description for this ingredient yet.

Glyceryl acrylate/acrylic acid copolymer is the fancy word for a common polymer (big molecule from repeated subunits), namely polyacrylic acid (aka carbomer when it comes to cosmetics) with glycerin attached to it in some places.

The main thing of this polymer is that it forms a hydrogel (trade named Lubrajel) that can sit on top of the skin and provide moisturizing, water-soluble ingredients such as glycerin to the skin. Think of it as a very thin, wet sponge that a cosmetic manufacturer can fill with good ingredients for your skin. It also works as a thickening agent (remember, it is a carbomer type of molecule), and can provide the skin with a nice slippery feel. It can also draw water to the skin (thank you, pendant glycerol groups!), providing skin hydration.

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Also, don’t let people scare you into thinking polyacrylic acid is dangerous because of the toxicity of acrylic acid. Since acrylic acid is dangerous due to its ability to absorb into the skin (since it’s small), when you chain them together into a polymer (which is big), this danger is no longer significant.

What-it-does: emollient | Irritancy: 0 | Comedogenicity: 1

Probably the most common silicone of all. It is a polymer (created from repeating subunits) molecule and has different molecular weight and thus different viscosity versions from water-light to thick liquid.

As for skincare, it makes the skin silky smooth, creates a subtle gloss and forms a protective barrier (aka occlusive). Also, works well to fill in fine lines and wrinkles and give skin a plump look (of course that is only temporary, but still, it's nice). There are also scar treatment gels out there using dimethicone as their base ingredient. It helps to soften scars and increase their elasticity. 

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As for hair care, it is a non-volatile silicone meaning that it stays on the hair rather than evaporates from it and smoothes the hair like no other thing. Depending on your hair type, it can be a bit difficult to wash out and might cause some build-up (btw, this is not true to all silicones, only the non-volatile types). 

A thick, high molecular weight silicone that is usually diluted in another, lighter silicone fluid (like dimethicone or cyclopentasiloxane). The dimethiconol containing silicone blends leave a silky smooth, non-greasy film on the skin.

There is not much info about this guy in itself other than it helps to thicken up products and stabilize oil-in-water emulsions. It usually comes to the formula as part of some thickener complex. For example, coupled with isohexadecane and polysorbate 80, the trio forms an instant gel upon mixing with water. 

What-it-does: chelating

Super common little helper ingredient that helps products to remain nice and stable for a longer time. It does so by neutralizing the metal ions in the formula (that usually get into there from water) that would otherwise cause some not so nice changes.

Also-called: Calmosensine | What-it-does: cell-communicating ingredient, soothing

 A soothing dipeptide (tyrosine + arginine) based molecule that functions as a "messenger of tranquility and muscle relaxation". It works via stimulating the skin nerve cells to release met-enkephalin, which is an opioid (i.e. relaxing, pain-relieving) messenger molecule. 

This means that Acetyl Dipeptide-1 Cetyl Ester can "signal" our skin cells to "relax" and it can instantly decrease skin irritations coming from heat, chemical stinging or mechanical stresses. It is also claimed to be able to prevent the onset of wrinkles and expression lines thanks to its muscle relaxation properties.

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Regarding the research, we could find one study that compared the calming effects of our guy with the soothing molecule called 4-T-Butylcyclohexanol. They irritated the skin with Capsaicin (the active in chili peppers) and examined how the test products relieved the burning/stinging sensation. They found that both molecules worked, but 4-t-Butylcyclohexanol worked somewhat better. 

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 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 emollient
irritancy, com. 3, 3
A mild, emollient liquid that can improve product spreadability and gives a silky and non-oily feel to the cosmetic products. 
what‑it‑does moisturizer/humectant | solvent
irritancy, com. 0, 1
An often used glycol that works as a solvent, humectant, penetration enhancer and also gives a good slip to the products. [more]
what‑it‑does solvent | moisturizer/humectant
A multi-functional, silky feeling helper ingredient that can do quite many things. It's used as an emulsion stabilizer, solvent, and a broad spectrum antimicrobial. [more]
what‑it‑does emulsifying
irritancy, com. 0, 0
It's a common little helper ingredient that helps water and oil to mix together. Also, it can help to increase the solubility of some other ingredients in the formula. 
what‑it‑does moisturizer/humectant | viscosity controlling
Glyceryl acrylate/acrylic acid copolymer is the fancy word for a common polymer (big molecule from repeated subunits), namely polyacrylic acid (aka carbomer when it comes to cosmetics) with glycerin attached to it in some places. The main thing of this polymer is that it forms a hydrogel (trade named Lubrajel) that can sit on top of the skin and provide moisturizing, water-soluble [more]
what‑it‑does emollient
irritancy, com. 0, 1
A very common silicone that gives both skin and hair a silky smooth feel. It also forms a protective barrier on the skin and fills in fine lines. Also used for scar treatment. [more]
what‑it‑does emollient | moisturizer/humectant
A thick, high molecular weight silicone that is usually diluted in a lighter silicone fluid. The dimethiconol containing silicone blends leave a silky smooth, non-greasy film on the skin. [more]
what‑it‑does viscosity controlling
A polymer that helps to thicken up products and stabilize oil-in-water emulsions. [more]
what‑it‑does chelating
Super common little helper ingredient that helps products to remain nice and stable for a longer time. It does so by neutralizing the metal ions in the formula (that usually get into there from water) that would otherwise cause some not so nice changes. [more]
what‑it‑does cell-communicating ingredient | soothing
 A soothing dipeptide (tyrosine + arginine) based molecule that functions as a "messenger of tranquility and muscle relaxation". It works via stimulating the skin nerve cells to release met-enkephalin, which is an opioid (i.e. relaxing, pain-relieving) messenger molecule. This means that Acetyl Dipeptide-1 Cetyl Ester can " [more]