Skin science article
Paula's Choice Defense Antioxidant Pore Purifier Versus Paula's Choice 10% Azelaic Acid Booster
Paula's Choice Defense Antioxidant Pore Purifier Versus Paula's Choice 10% Azelaic Acid Booster This pore-care treatment is formulated around Ascorbyl Glucoside and Salicylic Acid to refine the look of pores and balance excess oil. This calming treatment is fo
Paula's Choice Defense Antioxidant Pore Purifier Versus Paula's Choice 10% Azelaic Acid Booster
This pore-care treatment is formulated around Ascorbyl Glucoside and Salicylic Acid to refine the look of pores and balance excess oil.
This calming treatment is formulated around Azelaic Acid and Salicylic Acid to calm redness and fade the look of dark spots.
What's inside
Key Ingredients
Benefits
Concerns
Ingredients Side-by-side
Water
Propanediol
Butylene Glycol
Ethoxydiglycol
Glycerin
Ascorbyl Glucoside
Panthenol
Salicylic Acid
Camellia Sinensis Callus
Glycyrrhiza Glabra Root Extract
Potassium Azeloyl Diglycinate
Coffea Arabica Fruit Extract
Ceramide NP
Vitis Vinifera Seed Extract
Panax Ginseng Root Extract
Niacinamide
Phytic Acid
Epigallocatechin Gallate
Adenosine
Ubiquinone
Calendula Officinalis Flower Extract
Lonicera Caprifolium Flower Extract
Sodium Hyaluronate
Lecithin
Centella Asiatica Extract
Sucrose Stearate
Glycine Soja Seed Extract
Hydrogenated Lecithin
Carbomer
Tetrasodium Glutamate Diacetate
Caprylic/Capric Triglyceride
Caprylyl Glycol
Polysorbate 20
Polyglyceryl-10 Stearate
Hydroxyethylcellulose
Sodium Hydroxide
Ethylhexylglycerin
Phenoxyethanol
Water, Propanediol, Butylene Glycol, Ethoxydiglycol, Glycerin, Ascorbyl Glucoside, Panthenol, Salicylic Acid, Camellia Sinensis Callus, Glycyrrhiza Glabra Root Extract, Potassium Azeloyl Diglycinate, Coffea Arabica Fruit Extract, Ceramide NP, Vitis Vinifera Seed Extract, Panax Ginseng Root Extract, Niacinamide, Phytic Acid, Epigallocatechin Gallate, Adenosine, Ubiquinone, Calendula Officinalis Flower Extract, Lonicera Caprifolium Flower Extract, Sodium Hyaluronate, Lecithin, Centella Asiatica Extract, Sucrose Stearate, Glycine Soja Seed Extract, Hydrogenated Lecithin, Carbomer, Tetrasodium Glutamate Diacetate, Caprylic/Capric Triglyceride, Caprylyl Glycol, Polysorbate 20, Polyglyceryl-10 Stearate, Hydroxyethylcellulose, Sodium Hydroxide, Ethylhexylglycerin, Phenoxyethanol
Azelaic Acid
C12-15 Alkyl Benzoate
Methyl Glucose Sesquistearate
Cetearyl Alcohol
Glyceryl Stearate
Dimethicone
Boerhavia Diffusa Root Extract
Allantoin
Bisabolol
Cyclopentasiloxane
Xanthan Gum
Sclerotium Gum
Water, Azelaic Acid, C12-15 Alkyl Benzoate, Caprylic/Capric Triglyceride, Methyl Glucose Sesquistearate, Glycerin, Cetearyl Alcohol, Glyceryl Stearate, Dimethicone, Salicylic Acid, Adenosine, Glycyrrhiza Glabra Root Extract, Boerhavia Diffusa Root Extract, Allantoin, Bisabolol, Cyclopentasiloxane, Xanthan Gum, Sclerotium Gum, Propanediol, Butylene Glycol, Phenoxyethanol
Reviews
Alternatives
Ingredients Explained
These ingredients are found in both products.
Ingredients higher up in an ingredient list are typically present in a larger amount.
Adenosine is a purine nucleoside that your body already makes in every cell. In skincare, it acts mainly as a skin conditioning and anti-aging agent.
The way it works is fairly well mapped out:
Your skin has cells called fibroblasts that build collagen (the stuff that keeps skin firm and smooth). Adenosine basically flips a switch on these cells that tells them to get to work making more collagen and other proteins. These cells slow down on their own as skin ages, so Adenosine helps give them a little nudge to keep going.
The clinical backing is pretty solid too.
A blind, randomized, placebo-controlled trial of 126 women aged 45-65 tested a 0.1% cream twice daily and found real improvements in crow's feet and frown lines using a precise 3D skin-mapping technique; these changes showed up by week 3 and held at 2 months.
A later study using Adenosine-loaded dissolving microneedle patches reported gains in wrinkle depth, dermal density, elasticity, and hydration.
On concentrations, South Korea's Ministry of Food and Drug Safety has set 0.04% as the approved functional anti-wrinkle level. You'll typically see this ingredient used somewhere in the 0.04-0.1% range since it works at low doses.
This ingredient has been found safe for cosmetics with the data showing no irritation or sensitization.
Overall, this is a great ingredient for any anti-aging routine and has no photosensitizing effect, so it suits both AM and PM use.
Butylene Glycol (or BG) is used within cosmetic products for a few different reasons:
Overall, Butylene Glycol is a safe and well-rounded ingredient that works well with other ingredients.
Though this ingredient works well with most skin types, some people with sensitive skin may experience a reaction such as allergic rashes, closed comedones, or itchiness.
Caprylic/Capric Triglyceride (aka MCT Oil) is a lightweight emollient, solvent, and texture enhancer. It is considered a skin-softener by helping to prevent moisture loss.
Though it behaves like an oil, it is not technically one due to its chemical composition. One perk of this ingredient is that it is very stable, resistant to oxidation, and unlikely to go rancid.
In practice, that translates to a long shelf life and a consistently elegant skin feel.
While there is an assumption Caprylic Triglyceride can clog pores due to it being derived from coconut oil, there is no research supporting this. Just patch test if you have concerns.
Fractionated coconut oil and MCT Oil are both listed as Caprylic/Capric Triglyceride according to INCI. This is because INCI names are based on the ingredient’s final chemical composition and not its marketing name or source.
This ingredient is treated as the gold standard fungal acne safe oil. Even though it is coconut derived, the problematic lauric acid is stripped out.
This leaves just caprylic (C8) and capric (C10) acid. These chain lengths actually trend antifungal; a 2020 study found caprylic acid was enough to disrupt Malassezia furfur cell membrane, with a caprylic acid derivative damaging membrane structures at concentrations as low as 0.2%.
Glycerin (or glycerol) is a compound naturally found in your skin. It's a powerhouse humectant that pulls water into the stratum corneum.
Topically, glycerin does several things at once:
Your skin makes glycerin on its own (mostly from sebaceous oil breakdown) and shuttles it to your outermost layer of skin, or your epidermis, via aquaporin-3.
Aquaporin-3 is a transporter that is essential for normal skin hydration, elasticity, and repair. Interestingly, mice lacking in AQP3 have dry and less elastic skin that can be fully corrected with glycerin.
This ingredient is non-irritating, plays well with almost every ingredient, and works across all skin types. Typical use is anywhere between 3-10% but can go up to 79% in some leave-on products.
Just know very high concentrations (>40%) can feel tacky in low humidity.
Glycerin is the name for this ingredient in American English. British English uses Glycerol/Glycerine.
Glycyrrhiza Glabra Root Extract is an extract of the roots of Licorice. It has been found to have several benefits such as skin hydrating, conditioning, and soothing.
One component, glabridin, has extra potent antioxidant and soothing properties. It has also been found to block pigmentation from UVB rays in guinea pigs.
Licorice Root also contains a flavonoid. Flavonoids are a natural substance from in plants. Flavonoids also have antioxidant properties.
Another component, glycyrrhizin, has been found to have anti-inflammatory and antimicrobial benefits. This may make licorice root extract effective at treating acne. However, more research is needed to support this.
Liquiritin is one of the flavone compounds found in licorice. It has been found to help lighten skin by preventing tyrosinase from reacting with tyrosine. When the two react, protein is converted to melanin. Melanin is the substance in your body that gives your features pigmentation.
Phenoxyethanol is one of the most widely used preservatives in skincare (and for good reason!).
It has a large spectrum of antimicrobial activity and especially effective bacteria, yeast, and mold while only having a weak effect on your skin's natural microbiome.
On a cellular level, it disrupts the cell membranes of microbes by poking holes that make the cell leak. This shuts down the chemical reactions the microbe needs to make energy so it can no longer survive.
Another perk of this ingredient is that it stays functional across a wide pH range (3-10).
You'll often see it paired with boosters like Ethylhexylglycerin; one study showed that a 1:9 ratio of Ethylhexylglycerin to Phenoxyethanol damages bacterial membranes as effectively as doubling the Phenoxyethanol concentration on its own.
Typical use concentrations range from 0.3-1% depending on the formula, and this ingredient is capped at 1% int the EU.
Safety-wise, the fear mongering does not hold up to the evidence. The EU's Scientific Committee on Consumer Safety and FDA consider it safe as a preservative at up to 1%, including for children of all ages.
Adverse systemic effects only showed up in animal studies at exposures roughly 200x higher than what people get from cosmetics. And despite its very widespread use, this ingredient is a rare sensitizer and allergic reactions are uncommon.
Propanediol is an all-star ingredient. It softens, hydrates, and smooths the skin.
It’s often used to:
Propanediol is not likely to cause sensitivity and considered safe to use. It is derived from corn or petroleum with a clear color and no scent.
Salicylic Acid (also known as beta hydroxy acid or BHA) is a well-known ingredient for treating skin that struggles with acne and clogged pores. It exfoliates both the skin's surface and deep within the pores to help clear out buildup, control oil, and reduce inflammation.
Unlike AHAs (alpha hydroxy acids), salicylic acid is oil-soluble. This allows it to penetrate into pores which makes it especially effective for treating blackheads and preventing future breakouts.
Salicylic acid is also known for its soothing properties. It has a similar structure to aspirin and can calm inflamed or irritated skin, making it a good option for acne-prone skin that is also sensitive.
Concentrations of 0.5-2% are recognized by the U.S. FDA as an over-the-counter topical acne product.
It can cause irritation and/or dryness if one's skin already has a compromised moisture barrier, so it's best to focus on repairing that before introducing this ingredient into your routine.
While salicylic acid does not increase sun sensitivity, it’s still important to wear sunscreen daily to protect your skin.
If you are looking for the ingredient called BHA or Butylated Hydroxyanisole, click here.
Water. It's the most common cosmetic ingredient of all. You'll usually see it at the top of ingredient lists, meaning that it makes up the largest part of the product.
So why is it so popular? Water most often acts as a solvent - this means that it helps dissolve other ingredients into the formulation.
You'll also recognize water as that liquid we all need to stay alive. If you see this, drink a glass of water. Remember to stay hydrated!