Peptide Skincare & BeautySkin science and ingredient guides

Skin science article

Paula's Choice C5 Super Boost Eye Cream Versus CeraVe Eye Repair Cream

Paula's Choice C5 Super Boost Eye Cream Versus CeraVe Eye Repair Cream This brightening eye moisturizer is formulated around Ascorbyl Glucoside and 3-O-Ethyl Ascorbic Acid to brighten dull-looking skin and soften the look of wrinkles. This barrier-repair eye m

Paula's Choice C5 Super Boost Eye Cream Versus CeraVe Eye Repair Cream

This brightening eye moisturizer is formulated around Ascorbyl Glucoside and 3-O-Ethyl Ascorbic Acid to brighten dull-looking skin and soften the look of wrinkles.

This barrier-repair eye moisturizer is formulated around Niacinamide and Ceramide NP to strengthen the skin barrier and hydrate skin.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Dicaprylyl Carbonate

Glycerin

Triheptanoin

Ascorbyl Glucoside

3-O-Ethyl Ascorbic Acid

Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer

Arachidyl Alcohol

Cetearyl Alcohol

C13-15 Alkane

Ascorbyl Palmitate

Sh-Polypeptide-121

Acetyl Hexapeptide-8

Hyaluronic Acid

Zerumbone

Bacillus Ferment

Tocopherol

Tocopheryl Acetate

Butyrospermum Parkii Butter Unsaponifiables

Oryza Sativa Bran Extract

Rosmarinus Officinalis Leaf Extract

Helianthus Annuus Seed Oil

Helianthus Annuus Seed Extract

Hydrogenated Lecithin

Cetearyl Olivate

Sorbitan Olivate

Behenyl Alcohol

Arachidyl Glucoside

Propanediol

Butylene Glycol

Cetyl Alcohol

Sodium Phytate

Sodium Citrate

Citric Acid

Sodium Metabisulfite

Phenoxyethanol

Caprylyl Glycol

Ethylhexylglycerin

Hexylene Glycol

Sodium Hydroxide

Water, Dicaprylyl Carbonate, Glycerin, Triheptanoin, Ascorbyl Glucoside, 3-O-Ethyl Ascorbic Acid, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Arachidyl Alcohol, Cetearyl Alcohol, C13-15 Alkane, Ascorbyl Palmitate, Sh-Polypeptide-121, Acetyl Hexapeptide-8, Hyaluronic Acid, Zerumbone, Bacillus Ferment, Tocopherol, Tocopheryl Acetate, Butyrospermum Parkii Butter Unsaponifiables, Oryza Sativa Bran Extract, Rosmarinus Officinalis Leaf Extract, Helianthus Annuus Seed Oil, Helianthus Annuus Seed Extract, Hydrogenated Lecithin, Cetearyl Olivate, Sorbitan Olivate, Behenyl Alcohol, Arachidyl Glucoside, Propanediol, Butylene Glycol, Cetyl Alcohol, Sodium Phytate, Sodium Citrate, Citric Acid, Sodium Metabisulfite, Phenoxyethanol, Caprylyl Glycol, Ethylhexylglycerin, Hexylene Glycol, Sodium Hydroxide

Niacinamide

Caprylic/Capric Triglyceride

Isononyl Isononanoate

Jojoba Esters

PEG-20 Methyl Glucose Sesquistearate

Dimethicone

Methyl Glucose Sesquistearate

Asparagopsis Armata Extract

Ceramide NP

Ceramide AP

Potassium Sorbate

Ceramide EOP

Sorbitol

Carbomer

Zinc Citrate

Behentrimonium Methosulfate

Triethanolamine

Aloe Barbadensis Leaf Extract

Sodium Lauroyl Lactylate

Equisetum Arvense Extract

Sodium Hyaluronate

Cholesterol

Prunus Amygdalus Dulcis Oil

Ascophyllum Nodosum Extract

Laureth-4

Hydrogenated Vegetable Oil

Tetrasodium EDTA

Maltodextrin

Phytosphingosine

Xanthan Gum

Chrysanthellum Indicum Extract

Water, Niacinamide, Cetyl Alcohol, Caprylic/Capric Triglyceride, Glycerin, Propanediol, Isononyl Isononanoate, Jojoba Esters, PEG-20 Methyl Glucose Sesquistearate, Cetearyl Alcohol, Dimethicone, Methyl Glucose Sesquistearate, Asparagopsis Armata Extract, Ceramide NP, Ceramide AP, Potassium Sorbate, Ceramide EOP, Sorbitol, Carbomer, Zinc Citrate, Behentrimonium Methosulfate, Triethanolamine, Aloe Barbadensis Leaf Extract, Sodium Lauroyl Lactylate, Sodium Hydroxide, Equisetum Arvense Extract, Sodium Hyaluronate, Cholesterol, Phenoxyethanol, Prunus Amygdalus Dulcis Oil, Tocopherol, Ascophyllum Nodosum Extract, Laureth-4, Hydrogenated Vegetable Oil, Tetrasodium EDTA, Maltodextrin, Phytosphingosine, Xanthan Gum, Butylene Glycol, Ethylhexylglycerin, Chrysanthellum Indicum Extract

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.

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.

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.

Ethylhexylglycerin is created from glycerin. It is a multitasker ingredient that:

The CIR Expert Panel found minimal skin absorption or sensitization of any kind in a safety assessment. Though this ingredient is considered well-tolerated, a small number of cases of allergic dermatitis have been published since 2002. Just be sure to patch test if you are unsure.

Industry-reported use ranges from 8% in rinse-off products and 2% in leave-on formulations.

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.

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.

Sodium Hydroxide is also known as lye or caustic soda. It is used to adjust the pH of products; many ingredients require a specific pH to be effective.

In small amounts, sodium hydroxide is considered safe to use. However, large amounts may cause chemical burns due to its high alkaline.

Your skin has a natural pH and acid mantle. This acid mantle helps prevent harmful bacteria from breaking through. The acid mantle also helps keep your skin hydrated.

"Alkaline" refers to a high pH level. A low pH level would be considered acidic.

Tocopherol is a fat-soluble antioxidant known as Vitamin E.

You'll find this ingredient in the vast majority of skincare (for good reason). It works to neutralize free radicals, or unstable molecules generated by UV exposure, pollution, and other environmental stressors, before they can cause oxidative damage to your skin cells.

Topically applied tocopherol has been shown to protect against UV damage by ramping up the skin's own natural defense enzymes.

It also acts as a skin conditioning agent; some studies show that regular topical use can improve the skin's water-binding capacity over 2-4 weeks.

This ingredient is especially loved for being a team player. When combined with Vitamin C, the photoprotective effect of both ingredients roughly doubles and the combo also helps reduce UV-induced DNA damage.

This ingredient has some brightening potential but it's more of a prevention ingredient than spot-fader. Cell studies show it can slow down melanin production but it's worth noting that it's not the most powerful brightener out there.

In formulations, it also serves as a stabilizer that helps protect other oxidation-prone ingredients from degrading.

Concentrations usually range from 0.1-1% in most leave-on products.

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. 03Caprylic/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.
  4. 04Though 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.
  5. 05In practice, that translates to a long shelf life and a consistently elegant skin feel.
  6. 06While 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.
  7. 07Fractionated 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.
  8. 08This ingredient is treated as the gold standard fungal acne safe oil. Even though it is coconut derived, the problematic lauric acid is stripped out.
  9. 09This 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…
  10. 10Glycerin (or glycerol) is a compound naturally found in your skin. It's a powerhouse humectant that pulls water into the stratum corneum.
  11. 11Topically, glycerin does several things at once:
  12. 12Your 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.
  13. 13Aquaporin-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.
  14. 14This 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.
  15. 15Just know very high concentrations (>40%) can feel tacky in low humidity.
  16. 16Glycerin is the name for this ingredient in American English. British English uses Glycerol/Glycerine.
  17. 17Silica, also known as silicon dioxide, is a naturally occurring mineral. It is used as a fine, spherical, and porous powder in cosmetics.
  18. 18Though it has exfoliant properties, the function of silica varies depending on the product.
  19. 19The unique structure of silica enhances the spreadability and adds smoothness, making it a great texture enhancer.
  20. 20It is also used as an active carrier, emulsifier, and mattifier due to its ability to absorb excess oil.
Source · skinsort.com
02

Product index

Related product references

Product

Paula's Choice: PC 4 Men Shave

Paula's Choice: PC 4 Men Shave Paula's Choice: PC 4 Men Shave ingredients explained: Water (Aqua), Stearic Acid, Myristic Acid, Cocos Nucifera (Coconut) Oil, Glycerin, Potassium Hydroxide, …

Source: incidecoder.comView reference →
03

Comparison edit

Read side by side