Peptide Skincare & BeautySkin science and ingredient guides

Skin science article

Naturium Azelaic Topical Acid 10% Versus Paula's Choice Calm Redness Relief Repairing Serum

Naturium Azelaic Topical Acid 10% Versus Paula's Choice Calm Redness Relief Repairing Serum This calming serum is formulated around Potassium Azeloyl Diglycinate and Niacinamide to calm redness and fade the look of dark spots. This calming serum is formulated

Naturium Azelaic Topical Acid 10% Versus Paula's Choice Calm Redness Relief Repairing Serum

This calming serum is formulated around Potassium Azeloyl Diglycinate and Niacinamide to calm redness and fade the look of dark spots.

This calming serum is formulated around Beta-Glucan and Ceramide NP to calm redness and strengthen the skin barrier.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Propanediol

Potassium Azeloyl Diglycinate

Polyacrylate Crosspolymer-6

Niacinamide

3-O-Ethyl Ascorbic Acid

Caprylyl Glycol

Coffea Arabica Seed Extract

Sodium Hyaluronate

Phenylpropanol

Phenoxyethanol

Citric Acid

Potassium Chloride

Glycerin

Chlorphenesin

Tocopherol

Potassium Sorbate

Sodium Benzoate

Water, Propanediol, Potassium Azeloyl Diglycinate, Polyacrylate Crosspolymer-6, Niacinamide, 3-O-Ethyl Ascorbic Acid, Caprylyl Glycol, Coffea Arabica Seed Extract, Sodium Hyaluronate, Phenylpropanol, Phenoxyethanol, Citric Acid, Potassium Chloride, Glycerin, Chlorphenesin, Tocopherol, Potassium Sorbate, Sodium Benzoate

Hyaluronic Acid

Beta-Glucan

Sea Whip Extract

Ceramide NP

Ceramide AP

Ceramide EOP

Cholesterol

Glycyrrhiza Glabra Root Extract

Epilobium Angustifolium Flower/Leaf/Stem Extract

Phytosphingosine

Sodium Cocoyl Amino Acids

Chrysanthemum Parthenium Flower Extract

Glycine Soja Seed Extract

Ubiquinone

Sodium Lauroyl Lactylate

Caprylic/Capric Triglyceride

Magnesium Aspartate

Potassium Aspartate

Sarcosine

Xanthan Gum

Carbomer

Polysorbate 20

PEG/PPG-14/4 Dimethicone

Disodium EDTA

Ethylhexylglycerin

Water, Glycerin, Hyaluronic Acid, Beta-Glucan, Sea Whip Extract, Sodium Hyaluronate, Ceramide NP, Ceramide AP, Ceramide EOP, Cholesterol, Glycyrrhiza Glabra Root Extract, Epilobium Angustifolium Flower/Leaf/Stem Extract, Phytosphingosine, Sodium Cocoyl Amino Acids, Chrysanthemum Parthenium Flower Extract, Glycine Soja Seed Extract, Ubiquinone, Sodium Lauroyl Lactylate, Caprylic/Capric Triglyceride, Magnesium Aspartate, Potassium Aspartate, Sarcosine, Xanthan Gum, Carbomer, Polysorbate 20, PEG/PPG-14/4 Dimethicone, Disodium EDTA, Ethylhexylglycerin, 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.

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.

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.

Sodium Hyaluronate is the salt form of hyaluronic acid. It is a long sugar chain that is naturally found in your skin, joints, and connective tissue that maintains hydration and elasticity.

In skincare, it works as a humectant. It pulls water from the environment and deeper layers of skin and binds it to the surface.

Interestingly, the size of the molecule affects its behavior:

Some clinical evidence links low molecular weight versions to improved wrinkle depth, elasticity, anti-inflammatory effects, and barrier repair.

Many serums use a blend of both weights so you can get surface hydration plus longer-lasting and deeper effects.

You'll typically see concentrations between 0.1-2% for this ingredient.

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!

Similar Comparisons

The reference edit

Ingredients, questions
& further reading.

Connected source records selected through this article’s public topic index.

01

Formula cabinet

Ingredients & structured notes

Ingredient index

Ingredients Explained

  1. 01These ingredients are found in both products.
  2. 02Ingredients higher up in an ingredient list are typically present in a larger amount.
  3. 03C12-15 Alkyl Benzoate is a lightweight emollient made by combinig benzoic acid with fatty alcohols that are 12-15 carbons long.
  4. 04In cosmetics, it plays several roles:
  5. 05The Cosmetic Review Expert Panel has concluded the alkyl benzoate group to be safe as used in cosmetics; it wasn't found to be a skin irritant and unlikely to be absorbed due to its low water solubility.
  6. 06This report recorded almost 1000 reported uses with concentrations up to 59% in leave-on products but your cosmetics will typically use 0.5-15% depending on the product.
  7. 07It's often called a "SPF booster": this is because it keeps UV filters properly dissolved and evenly distributed to support a sunscreen's performance. It doesn't actually raise SPF on its own.
  8. 08Overall, this ingredient is well tolerated.
  9. 09This ingredient is fungal acne safe because it is an ester of benzoic acid.
  10. 10Think of this ingredient as two parts stuck together: an oily part and an acid part. Malassezia only gets a meal when it can snip off a fatty acid to eat. With C12-15 Alkyl Benzoate, the acid part is benzoic acid, which isn't a fatty acid and which …
  11. 11Benzoic acid is actually used as a preservative to stop yeast from growing.
  12. 12The oily part is a blend of C12-15 fatty alcohols but fatty alcohols in this size range can support only a little Malassezia growth (mostly for one species of Malassezia as well).
  13. 13In the ingredient, those alcohols stay locked inside the molecule. The yeast can only reach them by snipping the benzoate bond, and that type of bond is harder for it to cut than a normal fatty bond.
  14. 14So not much gets released. And whatever does get snipped comes packaged with benzoic acid, which discourages yeast growth.
  15. 15Caprylyl Glycol is a humectant, skin conditioner, emollient, and preservative booster derived from either caprylic acid or synthetically created.
  16. 16Typical use levels vary from 0.3-1% as a preservative booster and go up to 2% to condition skin.
  17. 17Because it is not a free-fatty acid, this ingredient is fungal acne safe (there's nothing for Malassezia to feed on).
  18. 18Phenoxyethanol is one of the most widely used preservatives in skincare (and for good reason!).
  19. 19It 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.
  20. 20On 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.
Source · skinsort.com
02

Product index

Related product references

03

Comparison edit

Read side by side