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Hada Labo Koi-Gokujyun Mask

Koi-Gokujyun Mask

Multifunctional mask moisturizes and soothes skin all at once thanks to the sheet’s layered structure infused with hydrating ingredients such as vitamin c derivative, vitamin e and hyaluronic acid.
Uploaded by: kanatheloli on

Hada Labo Koi-Gokujyun Mask
Ingredients explained

Also-called: Aqua | 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: 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.

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 >>

Diglycerin - goodie

The big brother of glycerin. It's also a natural moisturizing factor that reduces water evaporation from the upper layer of the skin and helps to keep water in the skin so that it stays nicely hydrated.

Compared to glycerin, it has a larger molecular structure (kind of a double glycerin). Thanks to this, it penetrates slower into the skin but gives longer lasting moisture and less sticky, better skin-feel.

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: moisturizer/humectant

Sodium Acetylated Hyaluronate is a variation of current IT moisturizer, Hyaluronic acid, where some water-loving -OH groups are replaced by amphipathic (partly water-loving and partly water-hating) acetyl groups. The modified molecule is claimed to have even better moisture retention ability than normal HA and better affinity to the skin surface. 

The better affinity comes from the acetyl groups that act as tiny "anchors" to attach the HA molecule to the skin. Staying on top of the skin better and longer means longer-lasting surface hydration and improved elasticity. It is also less sticky and more cosmetically elegant than normal HA, so no wonder the nickname of this molecule is super hyaluronic acid. 

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". 

We don't have description for this ingredient yet.

Squalane - goodie
What-it-does: skin-identical ingredient, emollient | Irritancy: 0 | Comedogenicity: 1

It seems to us that squalane is in fashion and there is a reason for it. Chemically speaking, it is a saturated  (no double bonds) hydrocarbon (a molecule consisting only of carbon and hydrogen), meaning that it's a nice and stable oily liquid with a long shelf life. 

It occurs naturally in certain fish and plant oils (e.g. olive), and in the sebum (the oily stuff our skin produces) of the human skin. As f.c. puts it in his awesome blog post, squalane's main things are "emolliency, surface occlusion, and TEWL prevention all with extreme cosmetic elegance". In other words, it's a superb moisturizer that makes your skin nice and smooth, without being heavy or greasy.

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

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. 

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

The most common type of feared-by-everyone-mostly-without-scientific-reason parabens. It's a cheap, effective and well-tolerated ingredient to make sure the cosmetic formula does not go wrong too soon

Apart from the general controversy around parabens (we wrote about it more here), there is a 2006 in-vitro (made in the lab not on real people) research about methylparaben (MP) showing that when exposed to sunlight, MP treated skin cells suffered more harm than non-MP treated skin cells. The study was not done with real people on real skin but still - using a good sunscreen next to MP containing products is a good idea. (Well, in fact using a sunscreen is always a good idea. :))

If you ever wondered what those little Listerine breath strips were made of, you found your answer! Pullulan is a polysaccharide polymer, which basically means that it’s a big molecule made up of smaller sugar molecule units.

It dissolves in water and can make a thin, elastic, and moisture-absorbing film when spread on the skin that can cause an instant tightening effect. It can also be used as a thickener to get a silicone-like feel and can be used in peel-off masks. Btw, it's made from fungus via fermentation. 

A smallish polymer molecule (created from repeated units of Polyethylene glycol, aka PEG) that's used as a solubilizer and viscosity control agent.

It is a clear, colorless liquid that is water-soluble and water-binding (aka humectant) and can help to solubilize sparingly-water soluble things (e.g. vanilla, perfumes) into water-based formulas. Thanks to its water-binding ability, it also prevents the drying out of formulas, especially when combined with the fellow hygroscopic agent, sorbitol

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: 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.

Though its long name does not reveal it, this polymer molecule (big molecule from repeated subunits or monomers) is a relative to the super common, water-loving thickener, Carbomer. Both of them are big molecules that contain acrylic acid units, but Acrylates/C10-30 Alkyl Acrylate Crosspolymer also contains some other monomers that are hydrophobic, i.e. water-hating. 

This means that our molecule is part water- and part oil-loving, so it not only works as a thickener but also as an emulsion stabilizer. It is very common in gel-type formulas that also contain an oil-phase as well as in cleansers as it also works with most cleansing agents (unlike a lot of other thickeners). 

What-it-does: buffering | Irritancy: 0 | Comedogenicity: 2

It’s a little helper ingredient that helps to set the pH of a cosmetic formulation to be just right. It’s very alkaline (you know the opposite of being very acidic): a 1% solution has a pH of around 10.

It does not have the very best safety reputation but in general, you do not have to worry about it. 

What-it-does: moisturizer/humectant

We don't have description for this ingredient yet.

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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]
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The big brother of glycerin. A natural moisturizing factor that compared to glycerin penetrates slower into the skin but gives longer lasting moisture and less sticky, better skin-feel. [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]
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Sodium Acetylated Hyaluronate is a variation of current IT moisturizer, Hyaluronic acid, where some water-loving -OH groups are replaced by amphipathic (partly water-loving and partly water-hating) acetyl groups. [more]
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An emollient and natural moisturizer that can be found also in the sebum (oily stuff our skin produces). It leaves a nice non-greasy, non-heavy feeling on the skin. [more]
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what‑it‑does preservative
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irritancy, com. 0, 0
The most common type of feared-by-everyone-mostly-without-scientific-reason parabens. It's a cheap, effective and well-tolerated ingredient to make sure the cosmetic formula does not go wrong too soon.  Apart from the general controversy around parabens (we wrote about it more here), there is a 2006 in-vitro (made in the lab not on real people) research about methylparaben (MP) sho [more]
If you ever wondered what those little Listerine breath strips were made of, you found your answer! Pullulan is a polysaccharide polymer, which basically means that it’s a big molecule made up of smaller sugar molecule units. It dissolves in water and can make a thin, elastic, and moisture-absorbing film when spread on the skin that can cause an instant tightening effect. [more]
what‑it‑does moisturizer/humectant | solvent
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what‑it‑does viscosity controlling
A super commonly used thickener and emulsion stabilizer. [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 viscosity controlling
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