Peptide Skincare & BeautySkin science and ingredient guides

Skin science article

La Roche-Posay Toleriane Dermallergo Ultra Soothing Repair Moisturizer Versus Dermatica Nourishing Ceramide + Peptide Moisturizer

La Roche-Posay Toleriane Dermallergo Ultra Soothing Repair Moisturizer Versus Dermatica Nourishing Ceramide + Peptide Moisturizer This barrier-repair moisturizer is formulated around Squalane and Butyrospermum Parkii Butter to strengthen the skin barrier and c

La Roche-Posay Toleriane Dermallergo Ultra Soothing Repair Moisturizer Versus Dermatica Nourishing Ceramide + Peptide Moisturizer

This barrier-repair moisturizer is formulated around Squalane and Butyrospermum Parkii Butter to strengthen the skin barrier and calm redness.

This barrier-repair moisturizer is formulated around Niacinamide and Ceramide NP to strengthen the skin barrier and soften the look of wrinkles.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Isocetyl Stearate

Squalane

Butyrospermum Parkii Butter

Dimethicone

Glycerin

Zea Mays Starch

Pentylene Glycol

Butylene Glycol

Glyceryl Stearate

PEG-100 Stearate

Cetyl Alcohol

Salvia Miltiorrhiza Root Extract

Dimethiconol

Sodium Hydroxide

Sphingomonas Ferment Extract

Caprylyl Glycol

Citric Acid

Acetyl Dipeptide-1 Cetyl Ester

Acrylates/C10-30 Alkyl Acrylate Crosspolymer

Water, Isocetyl Stearate, Squalane, Butyrospermum Parkii Butter, Dimethicone, Glycerin, Zea Mays Starch, Pentylene Glycol, Butylene Glycol, Glyceryl Stearate, PEG-100 Stearate, Cetyl Alcohol, Salvia Miltiorrhiza Root Extract, Dimethiconol, Sodium Hydroxide, Sphingomonas Ferment Extract, Caprylyl Glycol, Citric Acid, Acetyl Dipeptide-1 Cetyl Ester, Acrylates/C10-30 Alkyl Acrylate Crosspolymer

Cetearyl Alcohol

C12-15 Alkyl Benzoate

Niacinamide

Vitis Vinifera Oil

Panthenol

Sorbitan Stearate

Tocopheryl Acetate

Phenoxyethanol

Polyacrylate Crosspolymer-6

Sodium Lauroyl Lactylate

Centella Asiatica Extract

Ethylhexylglycerin

Sodium Hyaluronate

Trisodium Ethylenediamine Disuccinate

Carbomer

Ceramide NP

Ceramide AP

Phytosphingosine

Cholesterol

Polysorbate 20

Xanthan Gum

Palmitoyl Tripeptide-1

Palmitoyl Tetrapeptide-7

Ceramide EOP

Water, Cetearyl Alcohol, Glycerin, Butyrospermum Parkii Butter, C12-15 Alkyl Benzoate, Niacinamide, Vitis Vinifera Oil, Dimethicone, Panthenol, Sorbitan Stearate, Squalane, Tocopheryl Acetate, Phenoxyethanol, Butylene Glycol, Polyacrylate Crosspolymer-6, Sodium Lauroyl Lactylate, Centella Asiatica Extract, Ethylhexylglycerin, Sodium Hyaluronate, Trisodium Ethylenediamine Disuccinate, Citric Acid, Carbomer, Ceramide NP, Ceramide AP, Phytosphingosine, Cholesterol, Polysorbate 20, Xanthan Gum, Palmitoyl Tripeptide-1, Palmitoyl Tetrapeptide-7, Ceramide EOP

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.

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.

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.

Dimethicone is a type of synthetic silicone created from natural materials such as quartz. It is also known as polydimethylsiloxane.

What it does:

Dimethicone comes in different viscosities:

Depending on the viscosity, dimethicone has different properties.

Ingredients lists don't always show which type is used, so we recommend reaching out to the brand if you have questions about the viscosity.

This ingredient is unlikely to cause irritation because it does not get absorbed into skin. However, people with silicone allergies should be careful about using this ingredient.

Note: Dimethicone may contribute to pilling. This is because it is not oil or water soluble, so pilling may occur when layered with products. When mixed with heavy oils in a formula, the outcome is also quite greasy.

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.

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.

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. 03Butylene Glycol (or BG) is used within cosmetic products for a few different reasons:
  4. 04Overall, Butylene Glycol is a safe and well-rounded ingredient that works well with other ingredients.
  5. 05Though 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.
  6. 06C12-15 Alkyl Benzoate is a lightweight emollient made by combinig benzoic acid with fatty alcohols that are 12-15 carbons long.
  7. 07In cosmetics, it plays several roles:
  8. 08The Cosmetic Review Expert Panel has concluded the alkyl benzoate group to be safe as used in cosmetics; it wasn't found to be a skin irritant and unlikely to be absorbed due to its low water solubility.
  9. 09This report recorded almost 1000 reported uses with concentrations up to 59% in leave-on products but your cosmetics will typically use 0.5-15% depending on the product.
  10. 10It's often called a "SPF booster": this is because it keeps UV filters properly dissolved and evenly distributed to support a sunscreen's performance. It doesn't actually raise SPF on its own.
  11. 11Overall, this ingredient is well tolerated.
  12. 12This ingredient is fungal acne safe because it is an ester of benzoic acid.
  13. 13Think of this ingredient as two parts stuck together: an oily part and an acid part. Malassezia only gets a meal when it can snip off a fatty acid to eat. With C12-15 Alkyl Benzoate, the acid part is benzoic acid, which isn't a fatty acid and which …
  14. 14Benzoic acid is actually used as a preservative to stop yeast from growing.
  15. 15The oily part is a blend of C12-15 fatty alcohols but fatty alcohols in this size range can support only a little Malassezia growth (mostly for one species of Malassezia as well).
  16. 16In the ingredient, those alcohols stay locked inside the molecule. The yeast can only reach them by snipping the benzoate bond, and that type of bond is harder for it to cut than a normal fatty bond.
  17. 17So not much gets released. And whatever does get snipped comes packaged with benzoic acid, which discourages yeast growth.
  18. 18Carbomer 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.
  19. 19Although legally permitted at very high levels, carbomers are normally used at concentrations below 1%.
  20. 20It also needs to be neutralized to actually thicken, and because it is a large molecule, it doesn't really penetrate the skin barrier.
Source · skinsort.com
02

Product index

Related product references

03

Comparison edit

Read side by side