La Roche-Posay 10% Pure Niacinamide Serum Versus Paula's Choice 10% Azelaic Acid Booster

La Roche-Posay 10% Pure Niacinamide Serum Versus Paula's Choice 10% Azelaic Acid Booster

This brightening serum is formulated around Niacinamide and Phenylethyl Resorcinol to fade the look of dark spots and brighten dull-looking skin.

This calming treatment is formulated around Azelaic Acid and Salicylic Acid to calm redness and fade the look of dark spots.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Niacinamide

Glycerin

Alcohol Denat.

Hydroxyethylpiperazine Ethane Sulfonic Acid

Dimethicone

Isopropyl Lauroyl Sarcosinate

Octyldodecanol

PEG-20 Methyl Glucose Sesquistearate

Tin Oxide

Sorbitan Oleate

Dimethiconol

Cetearyl Ethylhexanoate

Isohexadecane

Sodium Hyaluronate

Phenylethyl Resorcinol

Poloxamer 338

Ammonium Polyacryloyldimethyl Taurate

Disodium EDTA

Isopropyl Myristate

Citric Acid

Xanthan Gum

Polysorbate 80

Acrylamide/Sodium Acryloyldimethyltaurate Copolymer

Tocopherol

Phenoxyethanol

Mica

CI 77891

Parfum

Water, Niacinamide, Glycerin, Alcohol Denat., Hydroxyethylpiperazine Ethane Sulfonic Acid, Dimethicone, Isopropyl Lauroyl Sarcosinate, Octyldodecanol, PEG-20 Methyl Glucose Sesquistearate, Tin Oxide, Sorbitan Oleate, Dimethiconol, Cetearyl Ethylhexanoate, Isohexadecane, Sodium Hyaluronate, Phenylethyl Resorcinol, Poloxamer 338, Ammonium Polyacryloyldimethyl Taurate, Disodium EDTA, Isopropyl Myristate, Citric Acid, Xanthan Gum, Polysorbate 80, Acrylamide/Sodium Acryloyldimethyltaurate Copolymer, Tocopherol, Phenoxyethanol, Mica, CI 77891, Parfum

Azelaic Acid

C12-15 Alkyl Benzoate

Caprylic/Capric Triglyceride

Methyl Glucose Sesquistearate

Cetearyl Alcohol

Glyceryl Stearate

Salicylic Acid

Adenosine

Glycyrrhiza Glabra Root Extract

Boerhavia Diffusa Root Extract

Allantoin

Bisabolol

Cyclopentasiloxane

Sclerotium Gum

Propanediol

Butylene Glycol

Water, Azelaic Acid, C12-15 Alkyl Benzoate, Caprylic/Capric Triglyceride, Methyl Glucose Sesquistearate, Glycerin, Cetearyl Alcohol, Glyceryl Stearate, Dimethicone, Salicylic Acid, Adenosine, Glycyrrhiza Glabra Root Extract, Boerhavia Diffusa Root Extract, Allantoin, Bisabolol, Cyclopentasiloxane, Xanthan Gum, Sclerotium Gum, Propanediol, Butylene Glycol, Phenoxyethanol

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.

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.

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.

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.

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