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Skin science article

La Roche-Posay 10% Pure Vitamin C Serum Versus The Purest Solutions Peptide Complex Serum

La Roche-Posay 10% Pure Vitamin C Serum Versus The Purest Solutions Peptide Complex Serum This brightening serum is formulated around Ascorbic Acid and Salicylic Acid to brighten dull-looking skin and refine skin texture. This anti-aging serum is formulated ar

La Roche-Posay 10% Pure Vitamin C Serum Versus The Purest Solutions Peptide Complex Serum

This brightening serum is formulated around Ascorbic Acid and Salicylic Acid to brighten dull-looking skin and refine skin texture.

This anti-aging serum is formulated around Sodium Hyaluronate and Acetyl Hexapeptide-8 to soften the look of wrinkles and hydrate skin.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Ascorbic Acid

Cyclohexasiloxane

Glycerin

Alcohol Denat.

Potassium Hydroxide

Polymethylsilsesquioxane

Polysilicone-11

Dimethicone

Propylene Glycol

Pentaerythrityl Tetraethylhexanoate

C13-14 Isoparaffin

Tocopherol

Sodium Hyaluronate

Hydrolyzed Hyaluronic Acid

Adenosine

Acetyl Dipeptide-1 Cetyl Ester

PEG-20 Methyl Glucose Sesquistearate

Poloxamer 338

Salicylic Acid

Polyacrylamide

Toluene Sulfonic Acid

Ammonium Polyacryloyldimethyl Taurate

Xanthan Gum

Caprylyl Glycol

Disodium EDTA

BHT

Laureth-7

Parfum

Water, Ascorbic Acid, Cyclohexasiloxane, Glycerin, Alcohol Denat., Potassium Hydroxide, Polymethylsilsesquioxane, Polysilicone-11, Dimethicone, Propylene Glycol, Pentaerythrityl Tetraethylhexanoate, C13-14 Isoparaffin, Tocopherol, Sodium Hyaluronate, Hydrolyzed Hyaluronic Acid, Adenosine, Acetyl Dipeptide-1 Cetyl Ester, PEG-20 Methyl Glucose Sesquistearate, Poloxamer 338, Salicylic Acid, Polyacrylamide, Toluene Sulfonic Acid, Ammonium Polyacryloyldimethyl Taurate, Xanthan Gum, Caprylyl Glycol, Disodium EDTA, BHT, Laureth-7, Parfum

Phenethyl Alcohol

Cetearyl Isononanoate

Sodium Polyacrylate

Propanediol

1,2-Hexanediol

Cetearyl Alcohol

Ceteareth-20

Hydrogenated Polydecene

Glyceryl Stearate

Trideceth-6

Acmella Oleracea Extract

Ceteareth-12

Cetyl Palmitate

Sodium PCA

Pentylene Glycol

Erythritol

Ethylhexylglycerin

Carrageenan

Sodium Acetylated Hyaluronate

Sodium Hyaluronate Crosspolymer

Acetyl Hexapeptide-8

Hydrolyzed Sodium Hyaluronate

Water, Phenethyl Alcohol, Propylene Glycol, Cetearyl Isononanoate, Sodium Polyacrylate, Propanediol, 1,2-Hexanediol, Cetearyl Alcohol, Ceteareth-20, Glycerin, Hydrogenated Polydecene, Glyceryl Stearate, Trideceth-6, Acmella Oleracea Extract, Ceteareth-12, Cetyl Palmitate, Sodium PCA, Pentylene Glycol, Erythritol, Ethylhexylglycerin, Caprylyl Glycol, Carrageenan, Sodium Acetylated Hyaluronate, Sodium Hyaluronate, Xanthan Gum, Sodium Hyaluronate Crosspolymer, Acetyl Hexapeptide-8, Hydrolyzed Sodium Hyaluronate

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Alternatives

Ingredients Explained

These ingredients are found in both products.

Ingredients higher up in an ingredient list are typically present in a larger amount.

Caprylyl Glycol is a humectant, skin conditioner, emollient, and preservative booster derived from either caprylic acid or synthetically created.

Typical use levels vary from 0.3-1% as a preservative booster and go up to 2% to condition skin.

Because it is not a free-fatty acid, this ingredient is fungal acne safe (there's nothing for Malassezia to feed on).

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.

Propylene Glycol is a synthetic, colorless, odorless liquid that has been a staple in cosmetics for decades. It is a skin conditioning agent, humectant, and solvent.

As a humectant, it draw water to the skin to reduce flaking and restore suppleness. It's also a solvent that helps dissolve other actives and keeps formulas stable across temperature changes.

The CIR Expert Panel has confirmed this ingredient to be nontoxic and clinical studies show no sensitization at cosmetic use concentrations.

True allergic reactions are quite rare: a 15-year retrospective study of 6,751 patients found only 0.31% had a positive reaction (and less than half were considered clinically relevant).

It seemed that when sensitization does occur, it's most commonly linked to topical medication (like corticosteroids) and not cosmetics. Allergic contact dermatitis also appears largely limited to individuals with underlying skin conditions.

Overall, propylene glycol is a well-studied ingredient that most people can tolerate without issue.

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.

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. 03Pentylene Glycol (1,2-pentanediol) is a multitasking little diol with three main roles in a formula:
  4. 04Research on alkanediols (the family pentylene glycol belongs to) show they work by disrupting microbial cell membranes. This disruption helps the primary preservative system in a product work more effectively at lower doses.
  5. 05On the safety side, the Cosmetic Ingredient Review Expert Panel has concluded this ingredient to be safe as used in current cosmetic practices + concentrations.
  6. 06Typical use levels in a formula run about 1-5%.
  7. 07Water. 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.
  8. 08So why is it so popular? Water most often acts as a solvent - this means that it helps dissolve other ingredients into the formulation.
  9. 09You'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!
  10. 10Xanthan 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.
  11. 11On the technical side of things, xanthan gum is a polysaccharide - a combination consisting of multiple sugar molecules bonded together.
  12. 12Xanthan 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.
Source · skinsort.com
02

Product index

Related product references

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Comparison edit

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