Peptide Skincare & BeautySkin science and ingredient guides

Skin science article

Paula's Choice Omega+ Complex Serum Versus Naturium Vitamin K Liposome Serum 3%

Paula's Choice Omega+ Complex Serum Versus Naturium Vitamin K Liposome Serum 3% This barrier-repair serum is formulated around Linoleic Acid and Linolenic Acid to strengthen the skin barrier and hydrate skin. This calming serum is formulated around Phospholipi

Paula's Choice Omega+ Complex Serum Versus Naturium Vitamin K Liposome Serum 3%

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

This calming serum is formulated around Phospholipids and Niacinamide to calm redness and strengthen the skin barrier.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

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

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

Propanediol

Phospholipids

Phytonadione Epoxide

Docosahexaenoic Acid

Pinus Pinaster Bark Extract

Eicosapentaenoic Acid

Phytosphingosine

Curcuma Longa Root Extract

Phosphatidylcholine

Niacinamide

Leuconostoc/Radish Root Ferment Filtrate

Polyacrylate Crosspolymer-6

Phenylpropanol

Arnica Montana Flower Extract

Cordyceps Sinensis Extract

Trametes Versicolor Extract

Caprylic/Capric Triglyceride

Bisabolol

Sorbitol

3-O-Ethyl Ascorbic Acid

Caprylyl Glycol

Phenoxyethanol

Butylene Glycol

T-Butyl Alcohol

Sodium Citrate

Tetrasodium Glutamate Diacetate

Tocopheryl Acetate

Potassium Sorbate

Sodium Benzoate

Water, Propanediol, Phospholipids, Phytonadione Epoxide, Linoleic Acid, Docosahexaenoic Acid, Pinus Pinaster Bark Extract, Eicosapentaenoic Acid, Phytosphingosine, Curcuma Longa Root Extract, Phosphatidylcholine, Niacinamide, Leuconostoc/Radish Root Ferment Filtrate, Polyacrylate Crosspolymer-6, Phenylpropanol, Linolenic Acid, Arnica Montana Flower Extract, Cordyceps Sinensis Extract, Trametes Versicolor Extract, Caprylic/Capric Triglyceride, Glycerin, Bisabolol, Sorbitol, 3-O-Ethyl Ascorbic Acid, Sodium Hyaluronate, Caprylyl Glycol, Phenoxyethanol, Butylene Glycol, Ethylhexylglycerin, T-Butyl Alcohol, Sodium Citrate, Xanthan Gum, Tetrasodium Glutamate Diacetate, Tocopheryl Acetate, Potassium Sorbate, Sodium Benzoate, Tocopherol, Citric 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.

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.

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.

Linoleic Acid is also known as Vitamin F. It is a fatty acid with emollient and skin conditioning properties.

Our top layer of skin, or epidermis, naturally contains high amounts of linoleic acid.

Your body uses linoleic acid to build ceramides and prostaglandins. Ceramides keep your skin's barrier hydrated and strong while prosaglandins help control inflammation and healing.

Needless to say, linoleic acid is crucial for having a strong skin barrier.

One study found applying linoleic acid rich sunflower oil to be more effective at repairing the skin barrier than olive oil.

This ingredient can also help treat acne by softening sebum to prevent clogged pores. Another study found using 2.5% linoleic acid gel for 4 weeks showed a 25% reduction in small comedones.

Studies show it can also help lighten hyperpigmentation or sun spots by disrupting the melanin production process. It also helps your skin shed melanin pigment from your skin caused by UV exposure.

Due to its role in the production of the fatty acid prostaglandin, linoleic acid can also help reduce inflammation and support wound healing.

Fun fact: Linoleic acid is an essential fatty acid. This means our bodies cannot create it on its own and we need to get it through foods such as nuts and vegetable oils.

Just know this ingredient is not always fungal-acne safe because it is a long-chain fatty acid (with 18 carbon atoms) that directly feeds the Malassezia yeast responsible for fungal acne.

Linolenic Acid is also known as "ALA" or alpha-linolenic acid. It is a key fatty acid.

Our skin uses this ingredient for maintaining a healthy skin barrier, regulating inflammation, and supporting keratinocyte function.

ALA is a great skin hydrator because it has the ability to restore lipids in our stratum corneum, or outermost layer of our skin; it also helps prevent transepidermal water loss.

This ingredient also helps soothe irritated skin by downregulating inflammation.

Chia seed oil is one of the highest natural sources of ALA. Research shows topical chia seed oil significantly improves skin hydration, reduces itch, and strengthens the barrier in both healthy and extremely dry skin.

Additionally, in-vivo and in-vitro studies show ALA exhibits antioxidant properties, reduces UV-induced inflammation, and supports wound healing.

Early research showed a fatty-acid deficiency in animals leads to abnormal skin barrier function. It is believed a deficiency in linolenic acid may be linked to skin disorders like eczema.

Fun fact: This ingredient is considered an essential fatty acid for humans. This means our bodies cannot naturally produce it and we must get it from food. Some foods rich in linolenic acid include walnuts, fish oils, soy, and canola.

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.

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.

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. 03This 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.
  4. 04Because 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).
  5. 05In 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!).
  6. 06Besides hydration, shea butter also contains triterpenes that have anti-inflammatory potential. In particule, lupeol cinnamate has shown the highest anti-inflammatory activity in vivo.
  7. 07Shea butter also contains vitamins A and E which may contribute to antioxidant activity.
  8. 08While Shea Butter has an SPF rating of about 3-4, it is not a sunscreen replacement.
  9. 09This ingredient may not be fungal acne safe because its fatty acids fall within the C11-C24 range that the Malassezia yeast can metabolize.
  10. 10Caprylic/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.
  11. 11Though 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.
  12. 12In practice, that translates to a long shelf life and a consistently elegant skin feel.
  13. 13While 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.
  14. 14Fractionated 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.
  15. 15This ingredient is treated as the gold standard fungal acne safe oil. Even though it is coconut derived, the problematic lauric acid is stripped out.
  16. 16This 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…
  17. 17Cetyl Alcohol is a fatty alcohol. Fatty Alcohols are most often used as an emollient or to thicken a product.
  18. 18Its main roles are:
  19. 19Though it has "alcohol" in the name, it is not related to denatured alcohol or ethyl alcohol.
  20. 20The FDA allows products labeled "alcohol-free" to have fatty alcohols.
Source · skinsort.com
02

Product index

Related product references

03

Comparison edit

Read side by side