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COSRX Shield Fit Snail Essence Sun SPF 50+

Shield Fit Snail Essence Sun SPF 50+

COSRX Shield Fit Snail Essence Sun SPF 50+ PA+++ is an essense-like, lightweight texture sun screen. Refresh your skin with snail mucin and rich humectant components which give the skin a petal-like, baby-skin soft finish.
Uploaded by: tanyao on

Skim through

Ingredient name what-it-does irr., com. ID-Rating
Water solvent
Homosalate sunscreen
Alcohol Denat antimicrobial/​antibacterial, solvent, viscosity controlling icky
Octocrylene sunscreen
Butylene Glycol moisturizer/​humectant, solvent 0, 1
Ethylhexyl Salicylate sunscreen 0, 0
Acrylates Copolymer viscosity controlling
Butyl Methoxydibenzoylmethane sunscreen goodie
Diphenylsiloxy Phenyl Trimethicone
Methyl Methacrylate Crosspolymer
Pentylene Glycol solvent, moisturizer/​humectant
Polymethylsilsesquioxane
Sodium Acrylate/Sodium Acryloyldimethyl Taurate Copolymer viscosity controlling
Isohexadecane emollient, solvent
Beheneth-25 surfactant/​cleansing, emulsifying
Caprylyl Glycol moisturizer/​humectant, emollient
Citrus Aurantium Bergamia (Bergamot) Fruit Oil perfuming icky
Polysorbate 80 emulsifying, surfactant/​cleansing 0, 0
Sorbitan Oleate emulsifying 0, 3
Citrus Nobilis (Mandarin Orange) Peel Oil perfuming icky
Disodium EDTA chelating
Ocimum Basilicum (Basil) Oil
Allantoin soothing 0, 0 goodie
Panthenol soothing, moisturizer/​humectant 0, 0 goodie
Dipropylene Glycol solvent
Maltodextrin
Moringa Pterygosperma Seed Extract
Sodium Palmitoyl Proline
1,2-Hexanediol solvent
Snail Secretion Filtrate antioxidant, moisturizer/​humectant goodie
Nymphaea Alba Flower Extract
Hyaluronic Acid skin-identical ingredient, moisturizer/​humectant goodie
Ethylhexylglycerin preservative
Pinus Pinaster Bark Extract antioxidant goodie
Hydrolyzed Hyaluronic Acid moisturizer/​humectant goodie
Sodium Hyaluronate skin-identical ingredient, moisturizer/​humectant 0, 0 goodie

COSRX Shield Fit Snail Essence Sun SPF 50+
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: sunscreen

An oil-soluble chemical sunscreen agent that protects the skin from UVB (295-315 nm) with a peak protection at 306 nm. Homosalate is not a strong UV filter in and of itself (gives only SPF 4.3 protection at max. allowed 10% concentration) and it is not photostable (looses 10% of its SPF protection in 45 mins) so it always has to be combined with other sunscreens for proper protection. Its big advantage, though, is that it is a liquid and is excellent for dissolving other hard to solubilize powder sunscreen agents, like the famous Avobenzone.

Regarding Homosalate's safety profile, we do not have the best news. In-vitro (made in the labs) studies have shown that it might have some estrogenic activity. Do not panic, these studies were not conducted on real humans under real world conditions. Still, if you are a 'better safe than sorry' type, be careful when using Homosalate containing sunscreens long-term and full-body.

  • It's a super common and super debated skincare ingredient
  • It has several benefits: great solvent, penetration enhancer, creates cosmetically elegant, light formulas, great astringent and antimicrobial
  • It can be very drying if it's in the first few ingredients on an ingredient list
  • Some experts even think that regular exposure to alcohol damages skin barrier and causes inflammation though it's a debated opinion (read more in geeky details tab)
Read all the geeky details about Alcohol Denat. here >>

What-it-does: sunscreen

An oil-soluble chemical sunscreen agent that protects skin in the UVB and somewhat in the UVA II range with a peak absorption of 304 nm. Its protection is not strong enough on its own but it is quite photostable (loses 10% of SPF protection in 95 mins) and is often used to stabilize other photo-unstable UV-filters, for example, Avobenzone. It is also often used to improve the water resistance of the products. 

Octocrylene's safety profile is generally quite good, though a review study in Contact Dermatitis reports an "increasing number of patients with photo contact allergy to octocrylene." Mainly adults with ketoprofen-sensitivity and children with sensitive skin are affected, so if you have a small kid, it is probably better to use octocrylene-free sunscreens.

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.

Also-called: Octyl Salicylate, Octisalate | What-it-does: sunscreen | Irritancy: 0 | Comedogenicity: 0

A colorless to light yellowish oily liquid that works as a UVB (280-320nm) sunscreen filter with a peak absorbance at 306 nm. It's not a strong filter in itself, it's always used in combination with other sunscreen agents to further enhance the SPF and to solubilize other solid UV filters.

It has a good safety profile and is allowed to be used at a max concentration of 5% both in the US and in Europe (10% is allowed in Japan).

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.

Also-called: Avobenzone | What-it-does: sunscreen

The famous Avobenzone. It is a special snowflake as it is the only globally available chemical sunscreen agent that provides proper UVA protection (in the US, new generation sunscreen agents are not approved because of impossible FDA regulations). It is the global gold standard of UVA protection and is the most used UVA sunscreen in the world. 

It gives very good protection across the whole UVA range (310-400 nm that is both UVA1 and UVA2) with a peak protection at 360 nm. The problem with it, though, is that it is not photostable and degrades in the sunlight. Wikipedia says that avobenzone loses 36% of its UV-absorption capacity after just one hour of sunlight (yep, this is one of the reasons why sunscreens have to be reapplied after a few hours).

We don't have description for this ingredient yet.

What-it-does: absorbent/mattifier

Porous spherical microbeads (tiny little balls) that can give an elegant silky texture to the products. They are also used to scatter light to reduce the look of fine lines on the skin, as well as to absorb excess oil and give a matt finish. 

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. 

spherical texturizing powder that's used as a texture enhancer and soft focus agent. It's claimed to give silicone type softness to the formula and also works as a (temporary) wrinkle filler. 

A copolymer is a big molecule that consists not of one but of two repeating subunits. This particular copolymer is a handy helper ingredient to form nice gel textures.

It usually comes to the formula combined with emollients (such as  C13-14 Isoparaffin, Isohexadecane, Isononyl Isononanoate or Squalane) and can be used as an emulsifier and/or thickener to produce milky gel emulsions with a soft and non-tacky skin feel. 

What-it-does: emollient, solvent

A light, velvety, unique skin feel liquid that is a good solvent and also makes the skin feel nice and smooth (aka emollient). It's often used in makeup products mixed with silicones to give shine and slip to the product. It's also great for cleansing dirt and oil from the skin as well as for taking off make-up.

We don't have description for this ingredient yet.

It’s a handy multi-tasking ingredient that gives the skin a nice, soft feel. At the same time, it also boosts the effectiveness of other preservatives, such as the nowadays super commonly used phenoxyethanol

The blend of these two (caprylyl glycol + phenoxyethanol) is called Optiphen, which not only helps to keep your cosmetics free from nasty things for a long time but also gives a good feel to the finished product. It's a popular duo.

Also-called: Bergamot Fruit Oil | What-it-does: perfuming

The essential oil coming from the fruit (probably the rind) of the bergamot orange.  It's a common top note in perfumes and contains (among others) fragrant compounds limonene (37%), linalyl acetate (30%) and linalool (8.8%). 

A well-known issue with bergamot oil (apart from the fragrance allergens) is that it contains phototoxic compounds called furanocoumarins, but more and more commonly furanocoumarin-free versions are used in cosmetic products. Still, if you have sensitive skin and prefer fragrance-free products, bergamot oil is not for you.

What-it-does: emulsifying, surfactant/cleansing | Irritancy: 0 | Comedogenicity: 0

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

The number at the end refers to the oil-loving part and the bigger the number  the more emulsifying power it has. 20 is a weak emulsifier, rather called solubilizer used commonly in toners while 60 and 80 are more common in serums and creams.

What-it-does: emulsifying | Irritancy: 0 | Comedogenicity: 3

A mainly oil-loving, vegetable raw material based ingredient that helps water and oil to mix together, aka emulsifier. It can also function as a wetting and dispersing agent helping insoluble particles such as color pigments or inorganic sunscreens (zinc/titanium dioxide) to disperse nice and even in liquids.  

Chemically speaking, it comes from the attachment of sorbitan (a dehydrated sorbitol (sugar) molecule) with the unsaturated fatty acid Oleic Acid, that creates a partly water (the sorbitan part) and partly oil soluble (oleic part) molecule. 

Also-called: Mandarin Orange Oil, Tangor Oil | What-it-does: perfuming

The essential oil coming from the peel of the mandarin orange or tangor. In general, the main component of citrus peel oils is limonene (77-86% for mandarin peel), a super common fragrant ingredient that makes everything smell nice (but counts as a frequent skin sensitizer).  Apart from smelling nice (and thus being a popular natural fragrance alternative), Mandarin Orange Oil also has significant antioxidant properties that's comparable to synthetic antioxidant BHT or oil-soluble antioxidant big shot vitamin E

On the con side, the fragrant components of citrus peels might irritate sensitive skin and citrus peels also contain the problematic compound called furanocoumarin that makes them (mildly) phototoxic. Orange mandarin peel contains less from it than some other citruses (like bergamot or lime), but still, be careful with it especially if it's in a product for daytime use.  

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.

Also-called: Basil Oil

We don't have description for this ingredient yet.

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.

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. 

What-it-does: solvent

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

It's a little helper ingredient coming from corn, rice or potato starch that can help to keep skin mat (absorbent), to stabilise emulsions, and to keep the product together (binding). 

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

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

Also-called: Snail Slime, Snail Mucin | What-it-does: antioxidant, moisturizer/humectant

If you are into the K-Beauty trend, you must have bumped into snail slime like a thousand times. Korean brands love the ingredient and tout it for its miraculous repair and hydration properties. It's claimed to be able to repair everything from dry patches, acne breakouts to signs of aging and we are happy to say that it might be just true.

So snail slime is the yucky stuff that snails (in cosmetics the secretion of Cornu Aspersum, the garden snail is used) produce when they are in stress (it's not the same as the one they secret to be able to move nicely and smoothly). As the cosmetic chemists at the Beauty Brains blog write, "chemically speaking, snail slime is a complex mixture of proteoglycans, glycosaminoglycans, glycoprotein enzymes, hyaluronic acid, copper peptides, antimicrobial peptides and trace elements including copper, zinc, and iron."   English translation equals it's loaded with a bunch of good-for-the-skin stuff.

We don't have description for this ingredient yet.

  • It’s naturally in our skin and behaves there like a sponge
  • It can bind up to 1000 times its own weight in water
  • It is a big molecule from repeated subunits (polymer) so different molecular weight versions exist (unfortunately there is no way to determine MW from INCI list only)
  • High-molecular-weight-HA (>500 kDa) is an excellent surface hydrator, skin protectant and can act as an osmotic pump helping water-soluble actives to penetrate deeper into the skin
  • Low-molecular-weight-HA (< 500 kDa) can hydrate the skin somewhat deeper though it is still a big molecule and works mainly in the epidermis (outer layer of the skin)
  • Low-molecular-weight-HA might also help the skin to repair itself by increasing its self-defense (~ 200kDa used in the study)
  • Ultra-low-molecular-weight-HA (<50kDa) is a controversial ingredient and might work as a pro-inflammatory signal molecule
Read all the geeky details about Hyaluronic Acid here >>

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

Also-called: Pycnogenol | What-it-does: antioxidant

A natural plant extract coming from the bark of the maritime pine that grows along the coast of southwest France. The extract contains potent antioxidant molecules, mainly procyanidins and phenolic acids.  Horphag Research trademarked the name 'Pycnogenol', which refers to a standardized, high-active content version of the pine bark extract. 

Pycnogenol is a very well researched ingredient with more than 370 published studies and review articles. Most of these are in-vitro (made in the lab, not on real people) or analyse Pycnogenol when taken orally. It's clear from them that Pycnogenol has a load of health benefits including antioxidant, anti-inflammatory, and anticarcinogenic magical properties (and a bunch of other things such as improving cognitive function, relieving premenstrual symptoms, or enhancing microcirculation). 

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: 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". 

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 sunscreen
An oil-soluble chemical sunscreen agent that protects the skin from UVB (295-315 nm) with a peak protection at 306 nm. Homosalate is not a strong UV filter in and of itself (gives only SPF 4.3 protection at max. [more]
what‑it‑does antimicrobial/antibacterial | solvent | viscosity controlling
Alcohol with some additives to make it unconsumable. It is great solvent, penetration enhancer, creates cosmetically elegant, light formulas, great astringent, and antimicrobial. In large amounts, it can be very drying to the skin. [more]
what‑it‑does sunscreen
An oil-soluble chemical sunscreen agent that protects skin in the UVB and somewhat in the UVA II range with a peak absorption of 304 nm. [more]
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 sunscreen
irritancy, com. 0, 0
A colorless to light yellowish oily liquid that works as a UVB (280-320nm) sunscreen filter with a peak absorbance at 306 nm. It's not a strong filter in itself, it's always used in combination with other sunscreen agents. [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 sunscreen
Avobenzone - the only globally available chemical sunscreen that gives proper UVA protection. It is not photostable so has to be combined with ingredients that help to stabilize it. [more]
Porous spherical microbeads that can give an elegant silky texture to the products. They are also used to scatter light to reduce the look of fine lines on the skin, as well as to absorb excess oil and give a matt finish. 
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]
A spherical texturizing powder that's used as a texture enhancer and soft focus agent. [more]
what‑it‑does viscosity controlling
A big molecule used as a helper ingredient to form nice gel textures. [more]
what‑it‑does emollient | solvent
A light, velvety, unique skin feel liquid that is a good solvent and also makes the skin feel nice and smooth. [more]
what‑it‑does surfactant/cleansing | emulsifying
what‑it‑does moisturizer/humectant | emollient
A handy multi-tasking ingredient that gives the skin a nice, soft feel and also boosts the effectiveness of other preservatives. [more]
what‑it‑does perfuming
The essential oil coming from the fruit (probably the rind) of the bergamot orange.  It's a common top note in perfumes and contains (among others) fragrant compounds limonene (37%), linalyl acetate (30%) and linalool (8.8%).  A well-known issue with bergamot oil (apart from the fragrance allergens) is that it contains phototoxic  [more]
what‑it‑does emulsifying | surfactant/cleansing
irritancy, com. 0, 0
A common little helper ingredient that helps water and oil to mix together, aka emulsifier. [more]
what‑it‑does emulsifying
irritancy, com. 0, 3
A mainly oil-loving, vegetable raw material based ingredient that helps water and oil to mix together, aka emulsifier. It can also function as a wetting and dispersing agent helping insoluble particles such as color pigments or inorganic sunscreens (zinc/titanium dioxide) to disperse nice and even in liquids.   [more]
what‑it‑does perfuming
The essential oil coming from the peel of the mandarin orange. Contains the fragrant component limonene (77-86%) and makes things smell nice. [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 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 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 solvent
A clear, colorless liquid that works as a solvent and viscosity decreasing ingredient. It also has great skin-moisturizing abilities.  [more]
It's a little helper ingredient coming from corn, rice or potato starch that can help to keep skin mat (absorbent), to stabilise emulsions, and to keep the product together (binding). 
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 antioxidant | moisturizer/humectant
If you are into the K-Beauty trend, you must have bumped into snail slime like a thousand times. Korean brands love the ingredient and tout it for its miraculous repair and hydration properties. [more]
what‑it‑does skin-identical ingredient | moisturizer/humectant
A famous natural moisturizing factor that can bind up to 1000 times its own weight in water. Works as an excellent surface hydrator in skincare. [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 antioxidant
Pycnogenol - A natural plant extract coming from the bark of the maritime pine. It's a well-researched and potent antioxidant. [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 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]