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La Roche-Posay Kerium Ds Cream

Kerium Ds Cream

Pro-desquamating soothing face care Neutralizes patches of red and flaking skin. Reinforces skin’s innate defense system
Uploaded by: disco on 14/07/2019

La Roche-Posay Kerium Ds Cream
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

An emollient ester with a rich and creamy but non-greasy skin feel. It makes skin supple and protects dry skin. 

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: 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). 

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: emollient | Irritancy: 2 | Comedogenicity: 0-5

It's a waxy emollient with a melting point near to skin temperature. It gives body and consistency to the formula and leaves a velvety feel on the skin. 

It has a high comedogenicity index (5 out of 5), so it might clog pores if you are prone to it. Famous dermatologist, Dr. Leslie Baumann also writes in her book, The Skin Type Solution to avoid this ingredient if you are acne-prone.

What-it-does: emollient, viscosity controlling | Irritancy: 0 | Comedogenicity: 2-3

A common multi-tasker fatty acid. It makes your skin feel nice and smooth (emollient), gives body to cream type products and helps to stabilize water and oil mixes (aka emulsions).

What-it-does: emulsifying

A white to beige powder that is described as the golden standard emulsifier for emulsions (oil+water mixtures) that are difficult to stabilize. It is especially popular in sunscreens as it can boost SPF protection and increase the water-resistance of the formula. 

Zinc Pca - goodie

If you have oily, acne-prone skin, Zinc PCA is one of the actives to put on your "TO TRY" list.

It's a synergistic association of two great things: Zinc and L-PCA. The Zinc part is there to help normalize sebum production and limit the proliferation of evil acne-causing bacteria. L-PCA stands for pyrrolidone carboxylic acid and it's a key molecule in the skin that helps with processes of hydration and energy (it's actually an NMF, a natural moisturizing factor).

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L-PCA is not only there to hydrate the skin, but it also helps to increase the efficacy and bioavailability of zinc. An in-vivo (done on real people) test done by the manufacturer shows that Zinc PCA reduces sebum production statistically significantly after 28 days of application (1% was used in the test), and in-vitro (made in the lab) measurements show that Zinc PCA has strong anti-microbial activity against P. acnes (between 0.1-0.25%) and other bacterial strains.

If that would not be enough there is also a 2011 research paper saying that based on in-vitro (made in the lab, not on real people)  findings Zinc PCA might be a promising anti-aging active that helps with the production of type I collagen (and we all know more collagen = firmer skin). 

All in all, definitely a goodie for oily, acne-prone skin

What-it-does: emulsifying | Irritancy: 2 | Comedogenicity: 3

An oily kind of ingredient that can magically blend with water all by itself. This is called self-emulsifying and SE in its name stands for that.

The difference between "normal" Glyceryl Stearate and this guy is that the SE grade contains a small amount of water-loving soap molecules, such as sodium stearate. This increases Glyceryl Stearate's affinity for water and gives it stronger emulsifying abilities.    

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Other than that, it’s a nice emollient that gives a smooth and soft appearance to the skin.

You can read some more at Glyceryl Stearate >>

Also-called: lye | What-it-does: buffering

The unfancy name for it is lye. It’s a solid white stuff that’s very alkaline and used in small amounts to adjust the pH of the product and make it just right. 

For example, in case of AHA or BHA exfoliants, the right pH is super-duper important, and pH adjusters like sodium hydroxide are needed.  

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BTW, lye is not something new. It was already used by ancient Egyptians to help oil and fat magically turn into something else. Can you guess what? Yes, it’s soap. It still often shows up in the ingredient list of soaps and other cleansers.

Sodium hydroxide in itself is a potent skin irritant, but once it's reacted (as it is usually in skin care products, like exfoliants) it is totally harmless.

What-it-does: skin-identical ingredient, emollient | Irritancy: 0 | Comedogenicity: 2

A fatty acid that can be found naturally in the skin. In fact, it's the most common saturated fatty acid found in animals and plants.

As for skincare, it can make the skin feel nice and smooth in moisturizers (emollient) or it can act as a foam building cleansing agent in cleansers. It's also a very popular ingredient in shaving foams. 

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.

What-it-does: surfactant/cleansing

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

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. 

It's one of the most commonly used thickeners and emulsion stabilizers. If the product is too runny, a little xanthan gum will make it more gel-like. Used alone, it can make the formula sticky and it is a good team player so it is usually combined with other thickeners and so-called rheology modifiers (helper ingredients that adjust the flow and thus the feel of the formula). The typical use level of Xantha Gum is below 1%, it is usually in the 0.1-0.5% range. 

Btw, Xanthan gum is all natural, a chain of sugar molecules (polysaccharide) produced from individual sugar molecules (glucose and sucrose) via fermentation. It’s approved by Ecocert and also used in the food industry (E415). 

What-it-does: viscosity controlling

A big polymer molecule that has a bunch of different versions and thus different uses. It can act as a film former,  as thickening agent, or it can increase the water-resistance in sunscreens. It is also used to entrap pigments/inorganic sunscreens within a micron size matrix for even coverage and easy application.

What-it-does: preservative

A helper ingredient that helps to make the products stay nice longer, aka preservative. It works mainly against fungi. 

It’s pH dependent and works best at acidic pH levels (3-5). It’s not strong enough to be used in itself so it’s always combined with something else, often with potassium sorbate.

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. 

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Other than having a good safety profile and being quite gentle to the skin it has some other advantages too. It can be used in many types of formulations as it has great thermal stability (can be heated up to 85°C) and works on a wide range of pH levels (ph 3-10). 

It’s often used together with ethylhexylglycerin as it nicely improves the preservative activity of phenoxyethanol.

What-it-does: preservative

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!). 

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
An emollient ester with a rich and creamy but non-greasy skin feel. [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. 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 viscosity controlling
A polymer that helps to thicken up products and stabilize oil-in-water emulsions. [more]
what‑it‑does emollient
irritancy, com. 2, 0-5
It's a waxy emollient with a melting point near to skin temperature. It gives body and consistency to the formula and leaves a velvety feel on the skin. It has a high comedogenicity index (5 out of 5), so it might clog pores if you are prone to it. [more]
what‑it‑does emollient | viscosity controlling
irritancy, com. 0, 2-3
A common multi-tasker fatty acid that works as an emollient, thickener and emulsion stabilizer. [more]
what‑it‑does emulsifying
A white to beige powder that is the golden standard emulsifier for emulsions (oil+water mixtures) that are difficult to stabilize. [more]
what‑it‑does anti-acne | moisturizer/humectant
A synergistic combination of Zinc and l-PCA that can reduce sebum production and limit the proliferation of evil acne-causing bacteria. A goodie for oily, acne-prone skin. [more]
what‑it‑does emulsifying
irritancy, com. 2, 3
An oily ingredient that can magically blend with water all by itself (called Self Emulsifying). Other than that it’s a nice emollient that gives a smooth and soft appearance to the skin. [more]
what‑it‑does buffering
Lye - A solid white stuff that’s very alkaline and used in small amount to adjust the pH of the product.  [more]
what‑it‑does skin-identical ingredient | emollient
irritancy, com. 0, 2
A fatty acid that can be found naturally in the skin. It can make the skin feel nice and smooth in moisturizers (emollient) or it can act as a foam building cleansing agent in cleansers. [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 surfactant/cleansing
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 viscosity controlling
A super commonly used thickener and emulsion stabilizer. [more]
what‑it‑does viscosity controlling
A big polymer molecule that has a bunch of different versions and thus different uses. It can act as a film former,  as a thickening agent, or it can increase the water-resistance in sunscreens. [more]
what‑it‑does preservative
A preservative that works mainly against fungi. Has to be combined with other preservatives. [more]
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 preservative
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]