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Skin science article

La Roche-Posay Retinol B3 Serum Versus Paula's Choice 10% Niacinamide Booster

La Roche-Posay Retinol B3 Serum Versus Paula's Choice 10% Niacinamide Booster This anti-aging serum is formulated around Niacinamide and Retinol to soften the look of wrinkles and fade the look of dark spots. This pore-care treatment is formulated around Niaci

La Roche-Posay Retinol B3 Serum Versus Paula's Choice 10% Niacinamide Booster

This anti-aging serum is formulated around Niacinamide and Retinol to soften the look of wrinkles and fade the look of dark spots.

This pore-care treatment is formulated around Niacinamide and Acetyl Glucosamine to refine the look of pores and refine skin texture.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Glycerin

Cyclohexasiloxane

Alcohol Denat.

Pentylene Glycol

Niacinamide

Dimethicone

Glycine Soja Oil

PPG-6-Decyltetradeceth-30

Sodium Hyaluronate

Retinol

Adenosine

Ammonium Polyacryloyldimethyl Taurate

Caprylyl Glycol

Citric Acid

Trisodium Ethylenediamine Disuccinate

Xanthan Gum

Polysilicone-11

Retinyl Palmitate

Tocopherol

Phenoxyethanol

Parfum

Water, Glycerin, Cyclohexasiloxane, Alcohol Denat., Pentylene Glycol, Niacinamide, Dimethicone, Glycine Soja Oil, PPG-6-Decyltetradeceth-30, Sodium Hyaluronate, Retinol, Adenosine, Ammonium Polyacryloyldimethyl Taurate, Caprylyl Glycol, Citric Acid, Trisodium Ethylenediamine Disuccinate, Xanthan Gum, Polysilicone-11, Retinyl Palmitate, Tocopherol, Phenoxyethanol, Parfum

Acetyl Glucosamine

Ascorbyl Glucoside

Butylene Glycol

Phospholipids

Allantoin

Boerhavia Diffusa Root Extract

Dipotassium Glycyrrhizate

Glycyrrhiza Glabra Root Extract

Ubiquinone

Epigallocatechin Gallate

Beta-Glucan

Panthenol

Carnosine

Genistein

Sodium Citrate

Sodium Hydroxide

Disodium EDTA

Ethylhexylglycerin

Water, Niacinamide, Acetyl Glucosamine, Ascorbyl Glucoside, Butylene Glycol, Phospholipids, Sodium Hyaluronate, Allantoin, Boerhavia Diffusa Root Extract, Glycerin, Dipotassium Glycyrrhizate, Glycyrrhiza Glabra Root Extract, Ubiquinone, Epigallocatechin Gallate, Beta-Glucan, Panthenol, Carnosine, Genistein, Citric Acid, Sodium Citrate, Sodium Hydroxide, Xanthan Gum, Disodium EDTA, Ethylhexylglycerin, 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.

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.

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.

Niacinamide is a multitasking form of vitamin B3 that strengthens the skin barrier, reduces pores and dark spots, regulates oil, and improves signs of aging.

And the best part? It's gentle and well-tolerated by most skin types, including sensitive and reactive skin.

You might have heard of "niacin flush", or the reddening of skin that causes itchiness. Niacinamide has not been found to cause this.

In very rare cases, some individuals may not be able to tolerate niacinamide at all or experience an allergic reaction to it.

If you are experiencing flaking, irritation, and dryness with this ingredient, be sure to double check all your products as this ingredient can be found in all categories of skincare.

When incorporating niacinamide into your routine, look out for concentration amounts. Typically, 5% niacinamide provides benefits such as fading dark spots. However, if you have sensitive skin, it is better to begin with a smaller concentration.

When you apply niacinamide to your skin, your body converts it into nicotinamide adenine dinucleotide (NAD). NAD is an essential coenzyme that is already found in your cells as "fuel" and powers countless biological processes.

In your skin, NAD helps repair cell damage, produce new healthy cells, support collagen production, strengthen the skin barrier, and fight environmental stressors (like UV and pollution).

Our natural NAD levels start to decline with age, leading to slower skin repair, visible aging, and a weaker skin barrier. By providing your skin niacinamide, you're recharging your skin's NAD levels. This leads to stronger, healthier, and younger looking skin.

Another name for vitamin B3 is nicotinamide. This vitamin is water-soluble and our bodies don't store it. We obtain Vitamin B3 from either food or skincare. Meat, fish, wheat, yeast, and leafy greens contain vitamin B3.

The type of niacinamide used in skincare is synthetically created.

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 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.

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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. 03Cyclopentasiloxane (D5) is a lightweight silicone that mostly acts as an emollient and solvent in cosmetics. Its the reason your products feel silky, fast-spreading, and non-greasy.
  4. 04Since D5 is volatile, it does its thing and then evaporates off the skin quickly.
  5. 05The safety profile of this ingredient is reassuring; the US CIR Expert Panel concluded D5 is safe as used in cosmetics and Health Canada concluded that D5 is not harmful to human health or the environment as currently used in cosmetics
  6. 06There's a study that people mention about D5 in a rat study showing tumors. This study is related to long-term inhalation of high D5 levels.
  7. 07Regulatory bodies have judged this study to be not applicable in topical skincare since skin absorption of D5 is very low and we're not really inhaling huge amounts of D5.
  8. 08The only restriction for this ingredient is environmental. The European Chemicals Agency (ECHA) restricted D5 in wash-off cosmetics at or above 0.1% due to their persistence in water.
  9. 09Dimethicone Crosspolymer is a silicone created by modifying dimethicone with hydrocarbon side chains. Due to its large size, it does not penetrate skin. It is considered non-occlusive.
  10. 10Dimethicone Crosspolymer is used to stabilize and thicken products. It also helps give products a silky feel.
  11. 11This ingredient is an synthetic emollient, emulsifier, and used as a surface treatment for pigment particles (like iron oxides or titanium dioxide).
  12. 12The “triisostearate” part of this ingredient is an ester derived from isostearic acid, a long-chain fatty acid.
  13. 13It "wraps" these ingredients in a form of slippery jacket so they disperse more evenly in oils, glide better on skin, and stick longer without smudging.
  14. 14Human repeat insult patch tests on foundations containing this ingredient found no sensitization concerns.
  15. 15Since isostearic acid is a C18 fatty acid, it falls within the carbon chain length that Malassezia can potentially metabolize. This is why this ingredient may not be fungal acne safe.
  16. 16Zinc Oxide (ZO) is a mineral broad-spectrum UV filter and the broadest-spectrum filter recognized by the FDA. It covers everything from UVB through to long-wave UVA.
  17. 17On top of sun protection, it has skin protectant and skin-soothing properties too.
  18. 18Here's a myth worth busting: mineral filters are usually described as working by "reflecting" or "bouncing" UV off your skin.
  19. 19That's mostly not true: when researchers actually measured it, ZO and Titanium Dioxide reflect only about 4-5% of UV (less than SPF 2 worth of protection).
  20. 20The vast majority of the work (~95%) is done by absorption, similar to chemical UV filters. ZO is a semiconductor that absorbs UV photos through its energy band gap.
Source · skinsort.com
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Product index

Related product references

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Comparison edit

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