Peptide Skincare & BeautySkin science and ingredient guides

Skin science article

SkinBetter Science Hydration Boosting Cream Versus Paula's Choice Skin Recovery Replenishing Moisturizer

SkinBetter Science Hydration Boosting Cream Versus Paula's Choice Skin Recovery Replenishing Moisturizer This barrier-repair moisturizer is formulated around Squalane and Niacinamide to strengthen the skin barrier and hydrate skin. This barrier-repair moisturi

SkinBetter Science Hydration Boosting Cream Versus Paula's Choice Skin Recovery Replenishing Moisturizer

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

This barrier-repair moisturizer is formulated around Oenothera Biennis Oil and Panthenol to strengthen the skin barrier and hydrate skin.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Glycerin

Squalane

Jojoba Oil/Macadamia Seed Oil Esters

Isosorbide Dicaprylate

Polyglyceryl-6 Distearate

Niacinamide

Ceramide NP

Ceramide Ns

Ceramide AP

Ceramide EOP

Ceramide Eos

Cholesterol

Sodium Hyaluronate

Xylitylglucoside

Anhydroxylitol

Betaine

Xylitol

Beta-Glucan

Hydrolyzed Jojoba Esters

Jojoba Esters

Glucose

Tocopheryl Acetate

Tocopherol

Ascorbyl Palmitate

Squalene

Phytosteryl Macadamiate

Phytosterols

Caprooyl Phytosphingosine

Caprooyl Sphingosine

Saccharide Isomerate

Polyglyceryl-3 Beeswax

Glyceryl Caprylate

Sodium Anisate

Ethylhexylglycerin

Cetyl Alcohol

Behenic Acid

Sodium Carrageenan

Sea Salt

Xanthan Gum

Algin

Carbomer

Polyacrylate Crosspolymer-11

Ceteareth-25

Sodium Citrate

Sodium Hydroxide

Citric Acid

Phenoxyethanol

Benzoic Acid

Sorbic Acid

Water, Glycerin, Squalane, Jojoba Oil/Macadamia Seed Oil Esters, Isosorbide Dicaprylate, Polyglyceryl-6 Distearate, Niacinamide, Ceramide NP, Ceramide Ns, Ceramide AP, Ceramide EOP, Ceramide Eos, Cholesterol, Sodium Hyaluronate, Xylitylglucoside, Anhydroxylitol, Betaine, Xylitol, Beta-Glucan, Hydrolyzed Jojoba Esters, Jojoba Esters, Glucose, Tocopheryl Acetate, Tocopherol, Ascorbyl Palmitate, Squalene, Phytosteryl Macadamiate, Phytosterols, Caprooyl Phytosphingosine, Caprooyl Sphingosine, Saccharide Isomerate, Polyglyceryl-3 Beeswax, Glyceryl Caprylate, Sodium Anisate, Ethylhexylglycerin, Cetyl Alcohol, Behenic Acid, Sodium Carrageenan, Sea Salt, Xanthan Gum, Algin, Carbomer, Polyacrylate Crosspolymer-11, Ceteareth-25, Sodium Citrate, Sodium Hydroxide, Citric Acid, Phenoxyethanol, Benzoic Acid, Sorbic Acid

Cetearyl Ethylhexanoate

Butylene Glycol

Glycereth-26

Oenothera Biennis Oil

Neopentyl Glycol Diheptanoate

Cyclopentasiloxane

Stearic Acid

Glyceryl Stearate

PEG-100 Stearate

Cyclohexasiloxane

Dimethicone

Panthenol

Palmitoyl Tripeptide-1

Palmitoyl Tetrapeptide-7

Tocopheryl Linoleate

Magnesium Ascorbyl Phosphate

Dipotassium Glycyrrhizate

Sodium PCA

Anthemis Nobilis Flower Extract

Aloe Barbadensis Leaf Juice

Sodium Ascorbyl Phosphate

Linoleic Acid

Linolenic Acid

Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate

Hydroxypropyl Guar

Allantoin

Rosa Moschata Seed Oil

Polysorbate 20

Cetyl Hydroxyethylcellulose

Trisodium EDTA

Batyl Alcohol

Chlorphenesin

Water, Cetearyl Ethylhexanoate, Butylene Glycol, Glycereth-26, Oenothera Biennis Oil, Cetyl Alcohol, Neopentyl Glycol Diheptanoate, Cyclopentasiloxane, Stearic Acid, Glyceryl Stearate, PEG-100 Stearate, Glycerin, Cyclohexasiloxane, Dimethicone, Panthenol, Palmitoyl Tripeptide-1, Palmitoyl Tetrapeptide-7, Sodium Hyaluronate, Tocopheryl Linoleate, Tocopheryl Acetate, Tocopherol, Magnesium Ascorbyl Phosphate, Ascorbyl Palmitate, Dipotassium Glycyrrhizate, Sodium PCA, Anthemis Nobilis Flower Extract, Aloe Barbadensis Leaf Juice, Sodium Ascorbyl Phosphate, Linoleic Acid, Linolenic Acid, Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate, Saccharide Isomerate, Hydroxypropyl Guar, Allantoin, Rosa Moschata Seed Oil, Polysorbate 20, Cetyl Hydroxyethylcellulose, Carbomer, Sodium Citrate, Trisodium EDTA, Batyl Alcohol, Sodium Hydroxide, Phenoxyethanol, Chlorphenesin, Benzoic Acid, Sorbic Acid

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.

Ascorbyl Palmitate is a fat-soluble form of vitamin C (Ascorbic Acid) made by combining it with palmitic acid.

It is able to blend easily into creams and oil-based formulas because it dissolves in oils rather than water.

As you may know, regular vitamin C is notorious for breaking down when exposed to sunlight and air. Ascorbyl Palmitate is more stable and degrades at a slower rate.

Research on whether it converts efficiently into active vitamin C once it's applied on your skin is still limited.

Some in-vitro studies suggest it may support collagen production, but it is not considered one of the stronger vitamin C derivatives, like:

Due to the palmitic acid base, this ingredient may not be fungal acne safe. Comedogenic studies have also shown this ingredient to have a rating of 2.

It's also worth keeping in mind that comedogenic and irritancy ratings are tested on individual ingredients, not finished formulas. The final product's formulation, concentration, and other ingredients all play a role in how something actually behaves on your skin.

Benzoic Acid is an organic acid that shows up in cosmetics as a preservative. It helps keep a product from spoiling by holding back the growth of yeast, mold, and some bacteria.

This ingredient also functions as a fragrance ingredient that helps mask the unpleasant scent of other ingredients.

The way it works is worth understanding; benzoic acid works when the formula is acidic. It is able to sneak into a microbe's cell and mess up how it functions to stop it from growing in an acidic product.

However, the acid switches to an inactive form and stops working if a product isn't acidic enough (above ~5 pH). This is why you'll often see it in low pH products or teamed up with other preservatives to cover the gap.

Safety wise, it's one of the better studied preservatives out there.

The Cosmetic Ingredient Review Expert Panel has concluded this ingredient to be safe for use in cosmetic formulations at concentrations up to 5%.

A large international review found this ingredient had no effects on the human body and had low irritation potential.

Just so you know, real world use is usually much lower than the 5% ceiling (usually 1% of less).

The EU caps it at 2.5% in rinse-off products, 1.7% in oral care, and 0.5% in leave-on products.

One thing worth mentioning (it's nothing to worry about): some people get a little stinging or flushing where they apply it. This isn't a true allergy; it's a temporary and harmless reaction. This is the same kind of mild tingle you might notice from sorbic acid.

Carbomer is a synthetic thickening and gelling agent. It's basically the ingredient that gives a lot of serums, gels, creams, and sunscreens their smooth, non-sticky texture.

Although legally permitted at very high levels, carbomers are normally used at concentrations below 1%.

It also needs to be neutralized to actually thicken, and because it is a large molecule, it doesn't really penetrate the skin barrier.

Allergy-wise, the risk is very low. Clinical studies show carbomers have low potential for skin irritation/sensitization even at concentrations up to 100%.

A 2024 UK study patch-tested 1,302 patients and found true allergy to the parent group of carbomer to be rare with no confirmed relevant reactions.

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.

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.

Saccharide Isomerate comes from sugars found in corn. It is a skin hydrator.

The structure of this ingredient can be altered to be more similar to the carbohydrates found in our skin. This ability to mimic our skin gives it hydrating properties.

Specifically, saccharide Isomerate is a humectant. Humectants draw moisture from the air to our skin.

Research shows Saccharide Isomerate to be an effective moisturizer.

Sodium Citrate is the sodium salts of citric acid. In skincare, it is used to alter pH levels and acts as a preservative.

Its main functions are to maintain the pH of a product and neutralize metal ions.

The acidity of our skin is maintained by our glands and skin biome; normal pH level of skin is slightly acidic (~4.75-5.5).

Being slightly acidic allows our skin to create an "acid mantle". This acid mantle is a thin barrier that protects our skin from bacteria and contaminants.

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.

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.

Sorbic Acid is a preservative that stops your product from spoiling by stopping microbes from growing.

As a preservative, it's kind of a specialist: it has a broad spectrum of activity against yeast and molds but is weaker against bacteria. That's why it's often paired with another preservative to cover that gap.

This ingredient is also pretty picky about pH; it performs best at pH 6.5 or below.

At the right pH level, sorbic acid is "active" and can slip through the outer wall of a microbe. Once inside, it turns the cell's interior more acidic to shut down the microbe from the inside.

The EU caps this ingredient at 0.6% while the CIR has concluded it's safe at concentrations up to 1%. It's most often used around 0.05-0.2% in cosmetics.

Though this ingredient is considered low-sensitizing and well-tolerated, a very small number of people may have a contact allergy to it. Be sure to patch test if you have a history of allergies towards preservatives.

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.

Tocopheryl Acetate is a stable, shelf-friendly form of vitamin E.

Formulators love it because plain vitamin E oxidizes quickly once it hits air. This acetate version stays stable and resists going off, helping to extend a product's shelf life.

It's actually inactive on its own and works like a slow-release "storage" form; the enzymes in your skin called esterases gradually convert it into active vitamin E over time.

One in vivo study showed 5% of the acetate in the living layer of the epidermis converted to vitamin E after 5 days of application. This study also found the skin gained protection against UV damage even though the conversion was slow and small.

Once converted, vitamin E acts as a skin's main fat-soluble antioxidant that fights free radicals to protect skin from damage.

Topical vitamin E generally boosts the skin's photoprotection, and it reduced UV-damage in animal models.

Overall, it has a pretty solid safety profile and has been found to be non-irritating and non-comedogenic. Allergic reactions may happen but stay rare due to how widely the ingredient gets used.

The concentration will vary depending on the formula; industry data shows 0.1% in baby lotions, 3% in lipsticks, and 5% in foot powders. You can also find this ingredient at 100% in a pure vitamin E oil.

Most leave-on skincare keeps it at the lower end, often between 0.5-1%.

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 Side-by-side

  1. 01Water
  2. 02Butyrospermum Parkii Butter
  3. 03Ceteareth-6 Olivate
  4. 04Butylene Glycol
  5. 05C13-15 Alkane
  6. 06Glycerin
  7. 07Glyceryl Stearate
  8. 08Polyglyceryl-4 Laurate
  9. 09Decyl Oleate
  10. 10Linum Usitatissimum Seed Oil
  11. 11Salvia Hispanica Seed Oil
  12. 12Olea Europaea Fruit Oil
  13. 13Passiflora Edulis Seed Oil
  14. 14Borago Officinalis Seed Oil
  15. 15Hydrogenated Olive Oil
  16. 16Psidium Guajava Fruit Extract
  17. 17Olea Europaea Oil Unsaponifiables
  18. 18Limnanthes Alba Seed Oil
  19. 19Linoleic Acid
  20. 20Linolenic Acid
Source · skinsort.com
02

Product index

Related product references

Product

Paula's Choice C15 Super Booster

Paula's Choice C15 Super Booster Paula's Choice C15 Super Booster ingredients explained: Aqua/Water/Eau⁠, Ascorbic Acid⁠, Glycerin⁠, Ethoxydiglycol⁠, PPG-26-Buteth-26⁠, Mannitol⁠, Tridecape…

Source: incidecoder.comView reference →
03

Comparison edit

Read side by side