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Puca Pure & Care Aha 2% Serum

Aha 2% Serum

Exfoliation of older skin Reduces large pores. Gives skin radiance and an even, clear tone. Smooths wrinkles and fine lines.
Uploaded by: sabjasinski on

Puca Pure & Care Aha 2% Serum
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. 

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: moisturizer/humectant, solvent, viscosity controlling | 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.

It’s an ingredient whose safety hasn’t been questioned so far by anyone (at least not that we know about). BG is approved by Ecocert and is also used enthusiastically in natural products. BTW, it’s also a food additive. 

Glycolic Acid - superstar
What-it-does: exfoliant, buffering
  • It’s the most researched AHA with the most proven skin benefits
  • It gently lifts off dead skin cells to reveal newer, fresher, smoother skin
  • It can help skin’s own collagen production that results in firmer, younger skin
  • It can fade brown spots caused by sun damage or PIH
  • Choose a product where you know the concentration and pH value because these two greatly influence effectiveness
  • Don’t forget to use your sunscreen (in any case but especially so next to an AHA product)
  • Slight stinging or burning with a stronger AHA product is normal
  • If your skin is very sensitive, rosacea prone choose rather a BHA or PHA product
Read all the geeky details about Glycolic Acid here >>

We don't have description for this ingredient yet.

Also-called: Aloe Leaf Extract | What-it-does: soothing, emollient, moisturizer/humectant

The extract coming from the juice containing leaves of the Aloe vera plant. It's usually a hydroglycolic extract (though  oil extract for the lipid parts also exists) that has similar moisturizing, emollient and anti-inflammatory properties as the juice itself. We have written some more about aloe here.

What-it-does: emollient, solvent

A water-loving emollient and humectant that gives a nice skin feel and slip to the product. It works well with facial toners.

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.

As for scientific proof that snail slime does something for the skin, we did find a couple of studies to go by. A Spanish radiation oncologist, Rafael Abad Iglesias MD discovered for the first time that snail mucin can be used to treat radiation dermatitis (skin irritation caused by radiotherapy, a form of cancer treatment). He did a clinical study with 100 patients and reported a "statistically significant clinical improvement in erythema, itching and burning pain" in the group treated with snail slime. 

A 2007 study examined the molecular basis for the great regeneration properties of the ingredient. It found that snail slime (SS) indeed does a bunch of positive things that could be the reason for its great repair abilities. First, it has serious antioxidant properties thanks to two great antioxidant enzymes, superoxide dismutase and glutathione s-transferase. Second, SS induces fibroblast proliferation, that's particularly important during wound healing. Third SS was also found to downregulate MMP, an evil enzyme that's out there to destroy skin-firming collagen. These properties add up to give SS not only wound healing and regenerative properties but also serious anti-aging potential. 

Regarding anti-aging, a 2013 study in the Journal of Drugs in Dermatology examined the effect of SS on photoaged skin. The 14-week, double-blind, 25 participant study found that "there was a significant degree of improvement in fines lines", though the participants did not report a significant difference in the quality of their skin.

All in all, we think that snail slime definitely deserves the skin goodie status it already enjoys in the K-beauty space. If you have no problem with somewhat strange, yucky things or animal derived ingredients in your products, it's worth a try.

What-it-does: moisturizer/humectant

We don't have description for this ingredient yet.

What-it-does: solvent, emulsifying, perfuming, surfactant/cleansing | Irritancy: 0-1 | Comedogenicity: 0-2

Similar to other glycols, it's a helper ingredient used as a solvent, or to thin out thick formulas and make them more nicely spreadable. 

Hexylene Glycol is also part a preservative blend named Lexgard® HPO, where it helps the effectiveness of current IT-preservative, phenoxyethanol

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).

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: 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.

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). 

Lactic Acid - superstar
  • It’s the second most researched AHA after glycolic acid
  • It gently lifts off dead skin cells to reveal newer, fresher, smoother skin
  • It also has amazing skin hydrating properties
  • In higher concentration (10% and up) it improves skin firmness, thickness and wrinkles
  • Choose a product where you know the concentration and pH value because these two greatly influence effectiveness
  • Don’t forget to use your sunscreen (in any case but especially so next to an AHA product)
Read all the geeky details about Lactic Acid here >>

What-it-does: moisturizer/humectant, solvent, viscosity controlling | Irritancy: 0 | Comedogenicity: 0
  • It's a helper ingredient that improves the freeze-thaw stability of products
  • It's also a solvent, humectant and to some extent a penetration enhancer
  • It has a bad reputation among natural cosmetics advocates but cosmetic scientists and toxicology experts do not agree (read more in the geeky details section)
Read all the geeky details about Propylene Glycol here >>

Also-called: Purslane Extract | What-it-does: soothing, antioxidant

Portulaca Oleracea is a nice succulent with bright yellow flowers and edible nutritious vegetables. It's a famous plant in Korean traditional medicine to treat infection and irritated skin.

Modern research confirms that it's loaded with skin-goodies: it's the richest green plant source of omega-3 fatty acids (α-linolenic acid), contains NMFs (polysaccharides and amino acids),  vitamins (β-carotene), minerals, and antioxidants (yellow betaxanthins and reddish betacyanins). Thanks to all its beneficial components, Purslane Extract has several magic properties: it's a great anti-inflammatory and antioxidant agent and also has wound healing abilities

We don't have description for this ingredient yet.

Also-called: Zemea | What-it-does: solvent, moisturizer/humectant

Propanediol is a natural alternative for the often used and often bad-mouthed propylene glycol. It's produced sustainably from corn sugar and it's Ecocert approved. 

It's quite a multi-tasker: can be used to improve skin moisturization, as a solvent, to boost preservative efficacy or to influence the sensory properties of the end formula. 

Beta-Glucan - goodie

Beta-Glucan is a nice big molecule composed of many smaller sugar molecules (called polysaccharide). It’s in the cell walls of yeast, some mushrooms, seaweeds, and cereals.

It’s a real goodie no matter if you eat it or put it on your face. Eating it is anti-diabetic, anti-cancer, and even lowers blood cholesterol. 

Putting it on your face also does a bunch of good things: it‘s shown to have intensive skin repairing & wound healing properties, it’s a mild antioxidant, a great skin soother, and moisturizer, and it even shows promising anti-aging benefits

The manufacturer of the ingredient did a published study with 27 people and examined the effect of 0.1% beta-glucan. They found that despite the large molecular size the smaller factions of beta-glucan penetrate into the skin, even into the dermis (the middle layer of the skin where wrinkles form). After 8 weeks there was a significant reduction of wrinkle depth and height and skin roughness has also improved greatly. 

Bottom line: Beta-glucan is a great ingredient, especially for sensitive or damaged skin. It soothes, moisturizes, and has some anti-aging magic properties. 

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.

Collagen**** - goodie
What-it-does: moisturizer/humectant

The big and important protein molecule that usually comes from animal skin such as fish or bovine. The gist of the "collagen in topical skincare" subject is to know that collagen in a jar has nothing to do with wrinkles but everything to do with skin hydration. We have a shiny explanation about this at soluble collagen, so click here to read more >> 

  • 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 >>

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.

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.  

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.

We don't have description for this ingredient yet.

We don't have description for this ingredient yet.

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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 moisturizer/humectant | solvent | viscosity controlling
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 exfoliant | buffering
The most researched and well-known AHA exfoliant. It gently lifts off dead skin cells to reveal newer, fresher, smoother skin. In larger concentration (>10%) it's a proven collagen booster. [more]
what‑it‑does soothing | emollient | moisturizer/humectant
The extract coming from the juice containing leaves of the Aloe vera plant with moisturizing, emollient and anti-inflammatory properties. [more]
what‑it‑does emollient | solvent
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irritancy, com. 0-1, 0-2
Similar to other glycols, it's a helper ingredient used as a solvent, or to thin out thick formulas and make them more nicely spreadable.  Hexylene Glycol is also part a preservative blend named Lexgard® [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 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 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
A super commonly used thickener and emulsion stabilizer. [more]
what‑it‑does exfoliant | moisturizer/humectant | buffering
A superstar AHA that not only exfoliates skin but is also a very good moisturizer. In higher concentration (10% and up) it can even improve skin firmness, thickness, and wrinkles. [more]
what‑it‑does moisturizer/humectant | solvent | viscosity controlling
irritancy, com. 0, 0
A common glycol that improves the freeze-thaw stability of products. It's also a solvent, humectant and to some extent a penetration enhancer. [more]
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Purslane Extract - a traditional Korean medicinal plant with skin-soothing, antioxidant and wound healing abilities. [more]
what‑it‑does solvent | moisturizer/humectant
A natural corn sugar derived glycol. It can be used to improve skin moisturization, as a solvent, to boost preservative efficacy or to influence the sensory properties of the end formula. [more]
what‑it‑does soothing | moisturizer/humectant
A great skin soother and moisturizer, and it even shows promising anti-aging benefits. It‘s also shown to have wound healing properties and is a mild antioxidant. [more]
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The big and important protein molecule that usually comes from animal skin such as fish or bovine. The gist of the "collagen in topical skincare" subject is to know that collagen in a jar has nothing to do with wrinkles but everything to do with skin hydration. [more]
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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 preservative
A not so strong preservative that doesn’t really work against bacteria, but more against mold and yeast. [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]