Peptide Skincare & BeautySkin science and ingredient guides

Skin science article

Paula's Choice Resist Anti-Aging Clear Skin Hydrator Versus Paula's Choice Omega+ Complex Serum

Paula's Choice Resist Anti-Aging Clear Skin Hydrator Versus Paula's Choice Omega+ Complex Serum This anti-aging moisturizer is formulated around Sodium Ascorbyl Phosphate and Niacinamide to soften the look of wrinkles and balance excess oil. This barrier-repai

Paula's Choice Resist Anti-Aging Clear Skin Hydrator Versus Paula's Choice Omega+ Complex Serum

This anti-aging moisturizer is formulated around Sodium Ascorbyl Phosphate and Niacinamide to soften the look of wrinkles and balance excess oil.

This barrier-repair serum is formulated around Linoleic Acid and Linolenic Acid to strengthen the skin barrier and hydrate skin.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Cyclopentasiloxane

Octyldodecyl Neopentanoate

Vinyl Dimethicone/Methicone Silsesquioxane Crosspolymer

Glycerin

Sodium Ascorbyl Phosphate

Cetyl Alcohol

Niacinamide

Dimethicone

Cetearyl Alcohol

Butylene Glycol

Glyceryl Stearate

PEG-100 Stearate

Adenosine

Epigallocatechin Gallate

Glucose Oxidase

Lactoperoxidase

Boerhavia Diffusa Root Extract

Cocos Nucifera Fruit Extract

Lactobacillus

Polysilicone-11

Sodium Chloride

Potassium Thiocyanate

Glucose

Xanthan Gum

Ceteareth-20

Decyl Glucoside

Citric Acid

Phenoxyethanol

Water, Cyclopentasiloxane, Octyldodecyl Neopentanoate, Vinyl Dimethicone/Methicone Silsesquioxane Crosspolymer, Glycerin, Sodium Ascorbyl Phosphate, Cetyl Alcohol, Niacinamide, Dimethicone, Cetearyl Alcohol, Butylene Glycol, Glyceryl Stearate, PEG-100 Stearate, Adenosine, Epigallocatechin Gallate, Glucose Oxidase, Lactoperoxidase, Boerhavia Diffusa Root Extract, Cocos Nucifera Fruit Extract, Lactobacillus, Polysilicone-11, Sodium Chloride, Potassium Thiocyanate, Glucose, Xanthan Gum, Ceteareth-20, Decyl Glucoside, Citric Acid, Phenoxyethanol

Diheptyl Succinate

Candelilla/Jojoba/Rice Bran Polyglyceryl-3 Esters

Linum Usitatissimum Seed Oil

Linoleic Acid

Linolenic Acid

Passiflora Edulis Seed Oil

Ceramide EOP

Ceramide Eos

Ceramide NP

Ceramide Ns

Caprooyl Sphingosine

Olea Europaea Oil Unsaponifiables

Caprooyl Phytosphingosine

Sodium Hyaluronate

Cholesterol

Ceramide AP

Butyrospermum Parkii Butter Unsaponifiables

Tocopherol

Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer

Prunus Domestica Seed Oil

Lauryl Laurate

Glyceryl Behenate

Hydrogenated Lecithin

Sodium Phytate

Trehalose

Isohexadecane

Sodium Stearoyl Lactylate

Capryloyl Glycerin/Sebacic Acid Copolymer

Tetrahexyldecyl Ascorbate

Agar

Ceteareth-25

Behenic Acid

Glyceryl Rosinate

Benzyl Alcohol

Ethylhexylglycerin

Water, Glycerin, Diheptyl Succinate, Candelilla/Jojoba/Rice Bran Polyglyceryl-3 Esters, Linum Usitatissimum Seed Oil, Linoleic Acid, Linolenic Acid, Passiflora Edulis Seed Oil, Ceramide EOP, Ceramide Eos, Ceramide NP, Ceramide Ns, Caprooyl Sphingosine, Olea Europaea Oil Unsaponifiables, Caprooyl Phytosphingosine, Sodium Hyaluronate, Cholesterol, Ceramide AP, Butyrospermum Parkii Butter Unsaponifiables, Tocopherol, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Prunus Domestica Seed Oil, Lauryl Laurate, Glyceryl Behenate, Hydrogenated Lecithin, Sodium Phytate, Trehalose, Isohexadecane, Sodium Stearoyl Lactylate, Capryloyl Glycerin/Sebacic Acid Copolymer, Xanthan Gum, Cetyl Alcohol, Tetrahexyldecyl Ascorbate, Agar, Glyceryl Stearate, Ceteareth-25, Cetearyl Alcohol, Behenic Acid, Glyceryl Rosinate, Citric Acid, Benzyl Alcohol, Ethylhexylglycerin

Reviews

Be the first to review

Alternatives

Ingredients Explained

These ingredients are found in both products.

Ingredients higher up in an ingredient list are typically present in a larger amount.

Cetearyl alcohol is a waxy mixture of two fatty alcohols: cetyl alcohol and stearyl alcohol. It is an emollient and emulsifier.

Despite having "alcohol" in its name, it has nothing to do with drying solvent alcohols; the FDA also allows "alcohol-free" products to contain fatty alcohols like this ingredient.

It plays several roles in a formula:

Typical use levels for this ingredient sit around 1-10% and the Cosmetic Ingredient Review Expert Panel has affirmed safety at concentrations up to 25% in leave-on products.

Multiple assessments have found it to be non-irritating and non-sensitizing to most people.

However, there have been some cases of allergic contact dermatitis in patients with chronically compromised skin barriers.

Cetearyl alcohol has a comedogenic rating of 2 and irritancy rating of 1. Both of these numbers come from the 1989 study that used rabbit ears; a "2" means mildly comedogenic and a "1" means low irritancy.

Here's the catch: rabbit skin is more sensitive than human skin and throws a lot of false positives. A 1996 reappraisal found that ingredients rated 1-2 in the rabbit ear tests are generally safe for humans.

Remember comedogenic ratings are unable to assess the entire formula of a product or how it will react on your skin. Just be sure to patch test if you are unsure about certain ingredients.

This ingredient is not fungal acne safe. Cetearyl alcohol is a fatty alcohol with chain lengths that fall within the range that Malassezia can metabolize.

A 2019 study has also observed Malassezia growth in the presence of this ingredient, confirming it to be not-fungal acne safe.

Cetyl Alcohol is a fatty alcohol. Fatty Alcohols are most often used as an emollient or to thicken a product.

Its main roles are:

Though it has "alcohol" in the name, it is not related to denatured alcohol or ethyl alcohol.

The FDA allows products labeled "alcohol-free" to have fatty alcohols.

This ingredient may not be fungal acne safe. It is a primary fatty alcohol with a chain length above 12 carbons. A study from 2019 show Malassezia can feed on fatty alcohols in this range, so it may trigger fungal acne in those prone to it.

Citric Acid is an alpha hydroxy acid (AHA) naturally found in citrus fruits like oranges, lemons, and limes.

Like other AHAs, citric acid can exfoliate skin by breaking down the bonds that hold dead skin cells together. This helps reveal smoother and brighter skin underneath.

However, this exfoliating effect only happens at high concentrations (20%) which can be hard to find in cosmetic products.

Due to this, citric acid is usually included in small amounts as a pH adjuster. This helps keep products slightly more acidic and compatible with skin's natural pH.

In skincare formulas, citric acid can:

While it can provide some skin benefits, research shows lactic acid and glycolic acid are generally more effective and less irritating exfoliants.

Most citric acid used in skincare today is made by fermenting sugars (usually from molasses). This synthetic version is identical to the natural citrus form but easier to stabilize and use in formulations.

Rosacea skin has a lower threshold for acids generally, with 62.5% of rosacea subjects in one study reacting to lactic acid in a sting test. This is why we mark citric acid as a potential rosacea trigger.

However, this ingredient shows up as a pH adjuster or chelator at roughly 0.1-1% in many products. These low levels are unlikely to be an issue for rosacea skin and becomes a potential trigger at exfoliating concentrations (20%). Because everybody's skin is unique, we recommend a patch test if you are unsure.

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.

Glyceryl Stearate is made by reacting glycerin with stearic acid (typically sourced from plant oils like palm or coconut). It's an emulsifier, emollient, and mild occlusive.

Emulsifiers help ingredients like oil and water stay mixed so your formula stays nicely blended and uniform in texture.

This ingredient is typically used in concentrations between 1-10%. Studies have found it to be non-sensitizing, non-phototoxic, and non-photoallergenic.

A close cousin of this ingredient is Glyceryl Stearate SE ("self-emulsifying"). This just has a small amount of sodium or potassium stearate added so it can emulsify without a co-emulsifier.

Since this ingredient is an ester of a C18 fatty acid, it may not be fungal acne safe. The Malassezia yeast can potentially metabolize within the C11-C24 range.

Fun fact: The human body also creates Glyceryl Stearate naturally.

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!

Xanthan gum is used as a stabilizer and thickener within cosmetic products. It helps give products a sticky, thick feeling - preventing them from being too runny.

On the technical side of things, xanthan gum is a polysaccharide - a combination consisting of multiple sugar molecules bonded together.

Xanthan gum is a pretty common and great ingredient. It is a natural, non-toxic, non-irritating ingredient that is also commonly used in food products.

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. 032,3-Butanediol is a naturally occurring humectant and solvent. It's created from fermentation and can be found in foods like cocoa butter and sweet corn.
  4. 04This ingredient attracts and holds onto moisture to boost hydration in skin. According to a manufacturer, this ingredient improves the spreadability of ingredients like vitamin C.
  5. 05Adenosine 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.
  6. 06The way it works is fairly well mapped out:
  7. 07Your 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 o…
  8. 08The clinical backing is pretty solid too.
  9. 09A 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…
  10. 10A later study using Adenosine-loaded dissolving microneedle patches reported gains in wrinkle depth, dermal density, elasticity, and hydration.
  11. 11On 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.
  12. 12This ingredient has been found safe for cosmetics with the data showing no irritation or sensitization.
  13. 13Overall, this is a great ingredient for any anti-aging routine and has no photosensitizing effect, so it suits both AM and PM use.
  14. 14This ingredient is also known as shea butter. It is a plant-derived extract from the nuts of the Africa shea tree and one of the most well-studied emollients.
  15. 15Because it has a high concentration of fatty acids (primarily oleic, stearic, and linoleic) it is able to form a protective barrier on the skin's surface. This helps seal in moisture and prevents transepidermal water loss (TEWL).
  16. 16In vitro research found an increase in skin hydration by 58% and a decrease in TEWL by 37.8% after 24 hours of applying this ingredient (pretty impressive for a single ingredient!).
  17. 17Besides hydration, shea butter also contains triterpenes that have anti-inflammatory potential. In particule, lupeol cinnamate has shown the highest anti-inflammatory activity in vivo.
  18. 18Shea butter also contains vitamins A and E which may contribute to antioxidant activity.
  19. 19While Shea Butter has an SPF rating of about 3-4, it is not a sunscreen replacement.
  20. 20This ingredient may not be fungal acne safe because its fatty acids fall within the C11-C24 range that the Malassezia yeast can metabolize.
Source · skinsort.com
02

Product index

Related product references

Product

Paula's Choice 5% Niacinamide Body Serum

Paula's Choice 5% Niacinamide Body Serum Paula's Choice 5% Niacinamide Body Serum ingredients explained: Water⁠, Panthenol⁠, Niacinamide⁠, Caprylic/Capric Triglyceride⁠, Myristyl Myristate⁠…

Source: incidecoder.comView reference →
03

Comparison edit

Read side by side