Skin science article
Paula's Choice Barrier Repair Advanced Moisturizer Versus SkinBetter Science AlphaRet Overnight Cream
Paula's Choice Barrier Repair Advanced Moisturizer Versus SkinBetter Science AlphaRet Overnight Cream This barrier-repair moisturizer is formulated around Squalane and Ceramide NP to strengthen the skin barrier and hydrate skin. This anti-aging night moisturiz
Paula's Choice Barrier Repair Advanced Moisturizer Versus SkinBetter Science AlphaRet Overnight Cream
This barrier-repair moisturizer is formulated around Squalane and Ceramide NP to strengthen the skin barrier and hydrate skin.
This anti-aging night moisturizer is formulated around Glycolic Acid and Niacinamide to soften the look of wrinkles and refine skin texture.
What's inside
Key Ingredients
Benefits
Concerns
Ingredients Side-by-side
Water
Dicaprylyl Carbonate
Ethylhexyl Stearate
Glycerin
Cocoglycerides
Squalane
Sodium Polyacrylate
Butyrospermum Parkii Butter
Ceramide NP
Ceramide AP
Ceramide As
Ceramide Ns
Ceramide EOP
Sodium Hyaluronate
Adenosine
Palmitoyl Tripeptide-5
Citrullus Lanatus Seed Oil
Glyceryl Stearate
Caprylyl Glycol
Hydroxyacetophenone
Sodium Stearoyl Glutamate
Hexylene Glycol
Tocopherol
2,3-Butanediol
Xanthan Gum
Ethylhexylglycerin
Sodium Phytate
Sodium PCA
Urea
Hydrogenated Lecithin
Trehalose
Polyquaternium-51
Triacetin
Cholesterol
Phenoxyethanol
Water, Dicaprylyl Carbonate, Ethylhexyl Stearate, Glycerin, Cocoglycerides, Squalane, Sodium Polyacrylate, Butyrospermum Parkii Butter, Ceramide NP, Ceramide AP, Ceramide As, Ceramide Ns, Ceramide EOP, Sodium Hyaluronate, Adenosine, Palmitoyl Tripeptide-5, Citrullus Lanatus Seed Oil, Glyceryl Stearate, Caprylyl Glycol, Hydroxyacetophenone, Sodium Stearoyl Glutamate, Hexylene Glycol, Tocopherol, 2,3-Butanediol, Xanthan Gum, Ethylhexylglycerin, Sodium Phytate, Sodium PCA, Urea, Hydrogenated Lecithin, Trehalose, Polyquaternium-51, Triacetin, Cholesterol, Phenoxyethanol
Sodium Glycolate
Glycolic Acid
Cetearyl Olivate
Pentylene Glycol
Cyclopentasiloxane
Isohexadecane
Sorbitan Olivate
Tetrahexyldecyl Ascorbate
Ceresin
Glycol Palmitate
Butylene Glycol
Niacinamide
Methyl Gluceth-20
Ethyl Lactyl Retinoate
Palmitoyl Tripeptide-1
Palmitoyl Tetrapeptide-7
Hyaluronic Acid
Ubiquinone
Bisabolol
Tocopheryl Acetate
Superoxide Dismutase
Allantoin Glycyrrhetinic Acid
Panthenol
Camellia Sinensis Leaf Extract
Portulaca Oleracea Extract
Linoleic Acid
Linolenic Acid
Magnesium Aluminum Silicate
Dimethyl Isosorbide
Dimethicone
PEG-100 Stearate
Steareth-2
Hydroxyethylcellulose
Acacia Senegal Gum
Hydrated Silica
Carbomer
Polysorbate 20
Tromethamine
Disodium EDTA
CI 77891
Water, Sodium Glycolate, Glycolic Acid, Cetearyl Olivate, Pentylene Glycol, Cyclopentasiloxane, Isohexadecane, Sorbitan Olivate, Tetrahexyldecyl Ascorbate, Glycerin, Ceresin, Glycol Palmitate, Butylene Glycol, Niacinamide, Squalane, Methyl Gluceth-20, Ethyl Lactyl Retinoate, Palmitoyl Tripeptide-1, Palmitoyl Tetrapeptide-7, Ceramide NP, Hyaluronic Acid, Ubiquinone, Tocopherol, Bisabolol, Tocopheryl Acetate, Superoxide Dismutase, Butyrospermum Parkii Butter, Allantoin Glycyrrhetinic Acid, Sodium PCA, Panthenol, Camellia Sinensis Leaf Extract, Portulaca Oleracea Extract, Linoleic Acid, Cholesterol, Linolenic Acid, Magnesium Aluminum Silicate, Dimethyl Isosorbide, Dimethicone, Glyceryl Stearate, PEG-100 Stearate, Steareth-2, Hydroxyethylcellulose, Acacia Senegal Gum, Xanthan Gum, Hydrated Silica, Carbomer, Polysorbate 20, Tromethamine, Disodium EDTA, Ethylhexylglycerin, Phenoxyethanol, CI 77891
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.
This 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.
Because 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).
In 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!).
Besides hydration, shea butter also contains triterpenes that have anti-inflammatory potential. In particule, lupeol cinnamate has shown the highest anti-inflammatory activity in vivo.
Shea butter also contains vitamins A and E which may contribute to antioxidant activity.
While Shea Butter has an SPF rating of about 3-4, it is not a sunscreen replacement.
This ingredient may not be fungal acne safe because its fatty acids fall within the C11-C24 range that the Malassezia yeast can metabolize.
Ceramide NP (formerly known as Ceramide 3) is one of the skin's naturally occurring lipids.
Since ceramides are the major lipid components of the skin, they are crucial for maintaining skin barrier and hydration. Ceramide NP most closely mirrors the dominant kind in human skin amongst ceramide subtypes.
This ceramide works by slotting into gaps within the stratum corneum's lipid matrix to limit trans-epidermal water loss (TEWL) and shield the skin against external irritants.
A study with 312 patients found that using a ceramide-containing routine for 4 weeks reduced the severity of atopic dermatitis by over 61%.
Another clinical study in subjects aged 60 and older found that a ceramide body wash and moisturizer improved skin dryness and itchy skin in 15 days.
Overall, ceramides are considered non-irritating and safety tests have found little to no observable adverse effects from using this ingredient.
Ceramide NP is usually sourced from plants (like soybean or rice bran), or produced synthetically.
Cholesterol is a lipid that is naturally found in human skin and is one of the three key components of your skin barrier. In skincare, it is an emollient and barrier-repairing ingredient.
It works by fitting directly into the lipid layers of skin to help restore structure and reduce transepidermal water loss (TEWL).
This is a great ingredient for dry, compromised, or aging skin; our skin starts to produce less cholesterol with age.
Research shows cholesterol works best in combination with ceramides and fatty acids, the other two major components in your skin barrier.
Cholesterol is also a well-establish penetration enhancer and can help other actives absorb more effectively.
Cosmetic-grade cholesterol is usually derived from lanolin but plant and synthetic options also exist. We recommend reaching out to the brand if you have questions about their source of cholesterol.
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.
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.
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 PCA (the salt of PCA) is one of the most well-established humectants in skincare.
Why is it so special? Your skin already makes it naturally; it's a natural component of your skin's Natural Moisturizing Factor (NMF), or the mix of water-binding compounds inside your skin cells that keeps things soft and hydrated.
As a cosmetic ingredient, it grabs water and holds it in the upper layers of skin to smooth roughness and ease dehydration.
There's some clinical support for the NMF approach with a study showing that a cream built to mimic the skin's NMF significantly boosted hydration.
Safety-wise, this ingredient non-irritating, non-comedogenic, and non-phototoxic in testing, with minimal skin absorption.
It also works really well with other hydrators like glycerin or hyaluronic acid, and typical usage is somewhere between 0.2-4%.
Squalane is the hydrogenated and shelf-stable form of squalene (a lipid that naturally occurs in human sebum).
It is an emollient and skin conditioning agent that is able to integrate seamlessly into the skin's lipid barrier without clogging pores.
This is due to how structurally similar it is to what your skin already produces.
Though it is mostly an emollient that helps soften and hydrate skin, it also has some humectant and occlusive action. Humectants help the skin retain moisture while occlusives seal it in, making squalane a triple-threat moisturizer.
Research shows it has antioxidant capabilities that help protect against stressors like UV exposure, specifically UVA induced oxidative stress. This study also found that it supports collagen biosynthesis in human dermal fibroblasts.
No clinical study has reported significant adverse effects and irritation reactions are very rare from this ingredient (even at 100% concentration).
Overall, it's a fantastic ingredient for hydration and is suitable for all skin types.
This depends on the source. Squalane can be derived from both plants and animals. Most squalane used in skincare comes from plants.
Please note: the source of squalane is only known if disclosed by the brand. We recommend reaching out to the brand if you have any questions about their squalane.
Read more about squalene with an "e".
Though squalane is often called an oil, it’s technically not one. It is a hydrocarbon, meaning it is only made of carbon and hydrogen. True oils are triglycerides and made of fatty acids and glycerol.
The term “oil-free” isn’t regulated so companies can define it however they want. Some exclude all oils, while others just avoid mineral oil or comedogenic oils.
Squalane has a comedogenic rating of 1 from the original 1972 study that tested raw ingredients under occlusion on rabbit ears. This system is not standardized or peer-reviewed, and using the raw ingredients is very different from how diluted cosmetic formulations are used on human skin.
A comedogenic rating of 1 means it is "unlikely to clog pores" according to the original rating system.
The overall formula of a product matters more than the individual ingredients on whether or not it will cause clogged pores.
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!
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.