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Oh K Overnight Hydratation Sleep Mask

Overnight Hydratation Sleep Mask

A deeply hydrating cream formula which can be applied before bedtime and left on for an intensive overnight dose of nourishment.
Uploaded by: karyane on

Oh K Overnight Hydratation Sleep Mask
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: solvent

A clear, colorless liquid that works as a solvent and viscosity decreasing ingredient. It also has great skin-moisturizing abilities. 

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 for dry skin at higher concentrations up to 20-40%
  • High-glycerin moisturizers are awesome for treating severely dry skin
Read all the geeky details about Glycerin here >>

We don't have description for this ingredient yet.

What-it-does: emollient

A clear, colorless, low viscosity, volatile (does not absorb into the skin but rather evaporates from it) silicone fluid that has excellent spreadability and leaves a light, silky and smooth feel on the skin.

According to manufacturer info, its big advantage is that it's compatible both with other silicones and with natural plant oils, so it's a great ingredient to formulate products with good-sounding, consumer-pleasing vegetable oils but still maintain a cosmetically elegant, non-greasy and non-tacky feel.

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

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

What-it-does: solvent

A really multi-functional helper ingredient that can do several things in a skincare product: it can bring a soft and pleasant feel to the formula, it can act as a humectant and emollient, it can be a solvent for some other ingredients (for example it can help to stabilize perfumes in watery products) and it can also help to disperse pigments more evenly in makeup products. And that is still not all: it can also boost the antimicrobial activity of preservatives

A common little helper ingredient that helps water and oil to mix together, aka emulsifier.

Also-called: Aristoflex AVC | What-it-does: viscosity controlling

A kind of polymer (big molecule from repeated subunits) that helps to create beautiful gel-like textures. It's also a texturizer and thickener for oil-in-water emulsions. It gives products a good skin feel and does not make the formula tacky or sticky. 

It works over a wide pH range and is used between 0.5-1.2%.

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. 

What-it-does: viscosity controlling

A white, elastomeric silicone powder that gives a nice silky and powdery feel to the products. It also has some oil and sebum absorption capabilities. 

What-it-does: viscosity controlling, emulsion stabilising | Irritancy: 0 | Comedogenicity: 1

A big molecule created from repeated subunits (a polymer of acrylic acid) that magically converts a liquid into a nice gel formula.  It usually has to be neutralized with a base (such as sodium hydroxide) for the thickening to occur and it creates viscous, clear gels that also feel nice and non-tacky on the skin. No wonder, it is a very popular and common ingredient. Typically used at 1% or less in most formulations.

What-it-does: buffering

It's a very alkaline stuff that helps to set the pH of the cosmetic formula to be just right. It's similar to the more often used sodium hydroxide and pretty much the same of what we wrote there applies here too. 

Allantoin - goodie
What-it-does: soothing | Irritancy: 0 | Comedogenicity: 0

Super common soothing ingredient. It can be found naturally in the roots & leaves of the comfrey plant, but more often than not what's in the cosmetic products is produced synthetically. 

It's not only soothing but it' also skin-softening and protecting and can promote wound healing.

What-it-does: skin-identical ingredient, moisturizer/humectant | Irritancy: 0 | Comedogenicity: 0

It’s the - sodium form - cousin of the famous NMFhyaluronic acid (HA). If HA does not tell you anything we have a super detailed, geeky explanation about it here.  The TL; DR version of HA is that it's a huge polymer (big molecule from repeated subunits) found in the skin that acts as a sponge helping the skin to hold onto water, being plump and elastic. HA is famous for its crazy water holding capacity as it can bind up to 1000 times its own weight in water.

As far as skincare goes, sodium hyaluronate and hyaluronic acid are pretty much the same and the two names are used interchangeably. As cosmetic chemist kindofstephen writes on reddit  "sodium hyaluronate disassociates into hyaluronic acid molecule and a sodium atom in solution". 

What-it-does: moisturizer/humectant

Hydrolyzed Hyaluronic Acid is a low molecular weight, chemically chopped up version of the naturally big molecule and current IT-moisturizer, Hyaluronic Acid (HA). The TL; DR version of HA is that it's a huge polymer (big molecule from repeated subunits) found in the skin that acts as a sponge helping the skin to retain water, making it plump and elastic. As HA is a polymer, the subunits can be repeated many times (as a high-molecular-weight version), or just a few times (as a low-molecular-weight version).

We wrote in detail at HA about how different molecular weight versions do different things both as a component of the skin and as a skincare ingredient, so click here and read about all the details. Hydrolyzed Hyaluronic Acid can also come in different molecular-weight versions with different properties:

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.

It is typically used in tiny amounts, around 0.1% or less.

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. 

What-it-does: preservative, deodorant

If you have spotted ethylhexylglycerin on the ingredient list, most probably you will see there also the current IT-preservative, phenoxyethanol. They are good friends because ethylhexylglycerin can boost the effectiveness of phenoxyethanol (and other preservatives) and as an added bonus it feels nice on the skin too.

Also, it's an effective deodorant and a medium spreading emollient

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: perfuming

It’s a common fragrance ingredient that is 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.

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

A common fragrance ingredient that has a sweet scent somewhere between lily and fruity melon. Can be found in essential oils, such as lavender oil, orange flower oil or ylang-ylang.

In cosmetics, it can be used up to 1%. 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.

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 solvent
A clear, colorless liquid that works as a solvent and viscosity decreasing ingredient. It also has great skin-moisturizing abilities.  [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 | viscosity controlling
what‑it‑does emollient
A light and volatile silicone fluid that has excellent spreadability and leaves a light, silky and smooth feel on the skin. [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 solvent
A multi-functional helper ingredient that acts as a humectant and emollient. It's also a solvent and can boost the effectiveness of preservatives. [more]
what‑it‑does emulsifying | surfactant/cleansing
A common little helper ingredient that helps water and oil to mix together, aka emulsifier.
what‑it‑does viscosity controlling
A kind of polymer (big molecule from repeated subunits) that helps to create beautiful gel-like textures. It's also a texturizer and thickener for oil-in-water emulsions. [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 white, elastomeric silicone powder that gives a nice silky and powdery feel to the products. [more]
what‑it‑does viscosity controlling
irritancy, com. 0, 1
A handy white powder that magically converts a liquid into a nice gel formula. [more]
what‑it‑does buffering
It's a very alkaline stuff that helps to set the pH of the cosmetic formula to be just right. [more]
what‑it‑does soothing
irritancy, com. 0, 0
Super common soothing ingredient. It can be found naturally in the roots & leaves of the comfrey plant, but more often than not what's in the cosmetic products is produced synthetically. It's not only soothing but it' [more]
what‑it‑does skin-identical ingredient | moisturizer/humectant
irritancy, com. 0, 0
It's the salt form of famous humectant and natural moisturizing factor, hyaluronic acid. It can bind huge amounts of water and it's pretty much the current IT-moisturizer. [more]
what‑it‑does moisturizer/humectant
Hydrolyzed Hyaluronic Acid is a low molecular weight, chemically chopped up version of the naturally big molecule and current IT-moisturizer, Hyaluronic Acid (HA). The TL; [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 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
It can boost the effectiveness of phenoxyethanol (and other preservatives) and as an added bonus it feels nice on the skin too. [more]
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 perfuming
It’s a common fragrance ingredient that is 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
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
A fragrance with a sweet scent somewhere between lily and fruity melon. [more]