Follow us on our new Insta page »
PCA  Skin Hydrating Mask

Hydrating Mask

An at-home hydrating mask with an advanced blend of soothing ingredients and botanicals that reduce irritation and infuse the skin with hydration.
Uploaded by: holisticbeautyuxbridge on

PCA Skin Hydrating 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. 

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 >>

Also-called: Oat Kernel Extract, Colloidal Oatmeal | What-it-does: antioxidant, soothing, emollient, abrasive/scrub

When you hear oatmeal, you probably think of breakfast, but the finely ground version of whole oat kernels, aka colloidal oatmeal, can do good things for your skin, especially if it's dry, itchy or prone to skin-rashes or eczema.

Oat is loaded with compounds good for the body, inside or outside, such as soothing agent beta-glucan (5%),  lipids (3-11%) including barrier repairing omega-3 and 6 fatty acids or phenolic antioxidant and anti-inflammatory agents (avenanthramides). 

The soothing, antioxidant and skin-protecting abilities of oat are so well-established that it is an active natural ingredient covered by the FDA OTC Skin Protectant monograph in the US, meaning that colloidal oatmeal can be claimed as an active ingredient on the INCI list and Aveeno is a mass-market brand built around oat-containing products.  

If your skin is dry, irritated, inflamed or eczema-prone, colloidal oatmeal is something to try.

Also-called: Soybean Oil | What-it-does: emollient, perfuming | Irritancy: 0 | Comedogenicity: 3

The emollient plant oil coming from the soybean. It is considered to be a nice, cost-effective base oil with moisturizing properties. As for its fatty acid profile, it contains 48-59% barrier-repairing linoleic acid, 17-30% nourishing oleic acid and also some (4.5-11%) potentially anti-inflammatory linolenic acid

Also-called: Safflower Seed Oil | What-it-does: antioxidant, emollient | Irritancy: 0 | Comedogenicity: 0-2

The oil coming from the seeds of the yellow flowered safflower plant. Similar to other plant oils, it's loaded with nourishing and moisturizing fatty acids: it's a high linoleic acid oil (70%) and has only smaller amounts of oleic acid (11%) (this might be great for acne-prone skin). It also contains antioxidant vitamin E (44mg/100g alpha-tocopherol).

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.    

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: Mel;Honey | What-it-does: soothing, moisturizer/humectant, antimicrobial/antibacterial

We all know honey as the sweet, gooey stuff that is lovely to sweeten a good cup of tea and we have good news about putting honey all over our skin. It is just as lovely on the skin as it is in the tea. 

The great review article about honey in the Journal of Cosmetic Dermatology writes that it is arguably the oldest skincare ingredient and evidence from around 4500 BC mentions honey in some eye cream recipes. Chemically speaking, it is a bee-derived, supersaturated sugar solution.  About 95% of honey dry weight is sugar and the other 5% consists of a great number of other minor components including proteins, amino acids, vitamins, enzymes, and minerals

This unique and complex chemical composition gives honey a bunch of nice skin care properties: it is very moisturizing, has soothing and antioxidant abilities as well as significant antibacterial and antifungal magic powers. There is also a lot of empirical evidence with emerging scientific backup that honey dressing promotes the healing of wounds and burns.

One tricky thing about honey though, is that it can have lots of different floral sources and different types of honey have a somewhat different composition and thus somewhat different properties. For example, the darker the honey the richer it is in antioxidant phenolic compounds.  Two special types of honey are acacia and manuka. The former is unique and popular because of its higher than usual fructose content that makes it more water-soluble and easier to stabilize in cosmetic formulas. The latter comes from the Leptospermum Scoparium tree native to New Zeland and its special thing is its extra strong antibacterial power due to a unique component called methylglyoxal.  

Overall, honey is a real skin-goodie in pretty much every shape and form, and it is a nice one to spot on the ingredient list. 

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. 

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.

We don't have description for this ingredient yet.

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). 

Sucrose - goodie

A type fo sugar, usually refined from cane or beet sugar. On the skin, it has water-binding properties and helps to keep your skin hydrated

Also-called: Benzoin Resin, Siam Benzoin | What-it-does: perfuming

The resin extract coming from a small, nice tree with white flowers living in South-East Asia. The resin has a nice sweet vanilla-like aroma (contains vanillin) and is used in perfumes as a fixative agent (it can help to slow down the evaporation of the other fragrant components making the scent more long lasting). 

It contains potential allergen components benzyl benzoate and benzyl cinnamate, so it's best to avoid if you have sensitive skin.

What-it-does: astringent

We don't have description for this ingredient yet.

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

What-it-does: preservative

It's one of those things that help your cosmetics not to go wrong too soon, aka a preservative. It’s not a strong one and doesn’t really work against bacteria, but more against mold and yeast. To do that it has to break down to its active form, sorbic acid. For that to happen, there has to be water in the product and the right pH value (pH 3-4). 

But even if everything is right, it’s not enough on its own. If you see potassium sorbate you should see some other preservative next to it too.

BTW, it’s also a food preservative and even has an E number, E202.

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". 

In spite of this, if you search for "hyaluronic acid vs sodium hyaluronate" you will find on multiple places that sodium hyaluronate is smaller and can penetrate the skin better. Chemically, this is definitely not true, as the two forms are almost the same, both are polymers and the subunits can be repeated in both forms as much as you like. (We also checked Prospector for sodium hyaluronate versions actually used in cosmetic products and found that the most common molecular weight was 1.5-1.8 million Da that absolutely counts as high molecular weight).

What seems to be a true difference, though, is that the salt form is more stable, easier to formulate and cheaper so it pops up more often on the ingredient lists. 

If you wanna become a real HA-and-the-skin expert you can read way more about the topic at hyaluronic acid (including penetration-questions, differences between high and low molecular weight versions and a bunch of references to scientific literature).

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. 

Another great thing about panthenol is that it has anti-inflammatory and skin protecting abilities. A study shows that it can reduce the irritation caused by less-nice other ingredients (e.g. fragrance, preservatives or chemical sunscreens) in the product.

Research also shows that it might be useful for wound healing as it promotes fibroblast (nice type of cells in our skin that produce skin-firming collagen) proliferation. 

If that wasn’t enough panthenol is also useful in nail and hair care products. A study shows that a nail treatment liquide with 2% panthenol could effectively get into the nail and significantly increase the hydration of it.

As for the hair the hydration effect is also true there. Panthenol might make your hair softer, more elastic and helps to comb your hair more easily. 

Also-called: Mountain Arnica Extract | What-it-does: perfuming

A nice yellow flower living in the mountains. It has been used as a herbal medicine for centuries, though its effect on skin is rather questionable. It's most famously used to treat bruisings, but there are some studies that show that it's not better than placebo (source: wikipedia).  Also, some consider it to be anti-inflammatory, while other research shows that it can cause skin irritation. 

Also-called: Cucumber Fruit Extract | What-it-does: soothing, emollient

Cucumber is a nice, non-irritating plant extract that’s known for it’s soothing and emollient properties. It’s not something new to put it on our face: even Cleopatra used it to “preserve her skin”.

It’s commonly believed that cucumber is the answer to puffy eyes, but there is no research confirming this. What research does confirm is that it contains amino acids and organic acids that’s helpful for the skin’s acid mantle. There is also an enzyme (called shikimate dehydrigenase) in the pulp that’s shown to have anti-inflammatory properties.

We don't have description for this ingredient yet.

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 antioxidant | soothing | emollient | abrasive/scrub
When you hear oatmeal, you probably think of breakfast, but the finely ground version of whole oat kernels, aka colloidal oatmeal, can do good things for your skin, especially if it's dry, itchy or prone to skin-rashes or eczema.Oat is loaded with compounds good for the body, inside or outside, such as soothing agent beta-glucan  [more]
what‑it‑does emollient | perfuming
irritancy, com. 0, 3
The emollient plant oil coming from the soybean. It is rich in barrier repairing linoleic acid (48-59%) and is generally a good moisturizing oil. [more]
what‑it‑does antioxidant | emollient
irritancy, com. 0, 0-2
Safflower Seed Oil - emollient plant oil with moisturizing fatty acids (linoleic: 70%, oleic: 11%) and antioxidant vitamin E (44mg/100g alpha-tocopherol). [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 soothing | moisturizer/humectant | antimicrobial/antibacterial
The sweet, gooey, sugar-laden stuff with skin moisturizing, soothing, antibacterial and some antioxidant properties. [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 viscosity controlling
what‑it‑does viscosity controlling
A super commonly used thickener and emulsion stabilizer. [more]
what‑it‑does moisturizer/humectant | soothing
A type fo sugar, usually refined from cane or beet sugar. On the skin, it is water-binding properties and helps to keep your skin hydrated.
what‑it‑does perfuming
A resin extract with a nice sweet vanilla-like aroma (contains vanillin). It's used in perfumes as a fixative agent. Also contains potential allergen fragrant components. [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 preservative
A not so strong preservative that doesn’t really work against bacteria, but more against mold and yeast. [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 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 perfuming
Mountain Arnica Extract - Most famously used to treat bruisings, though the scientific basis for its effectiveness is questionable. [more]
what‑it‑does soothing | emollient
Cucumber is a nice, non-irritating plant extract that’s known for it’s soothing and emollient properties. [more]