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Skin science article

Paula's Choice Resist Youth-Extending Daily Hydrating Fluid SPF 50 Versus La Roche-Posay Hydraphase Intense Light Rehydrating Face Moisturizer

Paula's Choice Resist Youth-Extending Daily Hydrating Fluid SPF 50 Versus La Roche-Posay Hydraphase Intense Light Rehydrating Face Moisturizer This hybrid sunscreen covers the full UV range and blocks ~98% of UVB at SPF 50. This oil-control moisturizer is form

Paula's Choice Resist Youth-Extending Daily Hydrating Fluid SPF 50 Versus La Roche-Posay Hydraphase Intense Light Rehydrating Face Moisturizer

This hybrid sunscreen covers the full UV range and blocks ~98% of UVB at SPF 50.

This oil-control moisturizer is formulated around Zinc Gluconate and Hydrolyzed Hyaluronic Acid to balance excess oil and hydrate skin.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Butyl Methoxydibenzoylmethane 2%

Ethylhexyl Methoxycinnamate 7.5%

Ethylhexyl Salicylate 5%

Octocrylene 2%

Water

Glycerin

Silica

Dimethicone

Tocopherol

Chamomilla Recutita Flower Extract

Vitis Vinifera Seed Extract

Camellia Sinensis Leaf Extract

Camellia Oleifera Leaf Extract

Peucedanum Graveolens Extract

Sambucus Nigra Fruit Extract

Avena Sativa Bran Extract

Punica Granatum Extract

Lycium Barbarum Fruit Extract

Hydrogenated Lecithin

Titanium Dioxide

Dimethicone/Vinyl Dimethicone Crosspolymer

Diethylhexyl Syringylidenemalonate

Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer

Xanthan Gum

Sodium Carbomer

Benzyl Alcohol

Sodium Benzoate

Potassium Sorbate

Phenoxyethanol

Butyl Methoxydibenzoylmethane 2%, Ethylhexyl Methoxycinnamate 7.5%, Ethylhexyl Salicylate 5%, Octocrylene 2%, Water, Glycerin, Silica, Dimethicone, Tocopherol, Chamomilla Recutita Flower Extract, Vitis Vinifera Seed Extract, Camellia Sinensis Leaf Extract, Camellia Oleifera Leaf Extract, Peucedanum Graveolens Extract, Sambucus Nigra Fruit Extract, Avena Sativa Bran Extract, Punica Granatum Extract, Lycium Barbarum Fruit Extract, Hydrogenated Lecithin, Titanium Dioxide, Dimethicone/Vinyl Dimethicone Crosspolymer, Diethylhexyl Syringylidenemalonate, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Xanthan Gum, Sodium Carbomer, Benzyl Alcohol, Sodium Benzoate, Potassium Sorbate, Phenoxyethanol

Hydrogenated Polyisobutene

Alcohol Denat.

Polyethylene

PEG-20 Stearate

PEG-100 Stearate

Carbomer

Zinc Gluconate

Glyceryl Stearate

Isohexadecane

Sodium Hydroxide

Disodium EDTA

Copper Sulfate

Hydrolyzed Hyaluronic Acid

Pentylene Glycol

Polysorbate 80

Acrylamide/Sodium Acryloyldimethyltaurate Copolymer

Cetyl Alcohol

Caprylyl Glycol

Parfum

Water, Hydrogenated Polyisobutene, Dimethicone, Glycerin, Alcohol Denat., Polyethylene, PEG-20 Stearate, PEG-100 Stearate, Carbomer, Zinc Gluconate, Glyceryl Stearate, Isohexadecane, Sodium Hydroxide, Disodium EDTA, Copper Sulfate, Hydrolyzed Hyaluronic Acid, Xanthan Gum, Pentylene Glycol, Polysorbate 80, Acrylamide/Sodium Acryloyldimethyltaurate Copolymer, Cetyl Alcohol, Caprylyl Glycol, Parfum

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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.

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.

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. 03Glycolic Acid is arguably the most famous alpha hydroxy acid (AHA) with tons of research backing its benefits.
  4. 04It is found naturally in sugar cane but the form used in skincare is usually synthetic for purity and stability.
  5. 05Glycolic acid removes the top layer of dead skin cells to allow newer and fresher ones to emerge.
  6. 06AHAs work by breaking down the structural “glue” that holds old skin cells in place. When that buildup is gone, your skin can renew itself more efficiently.
  7. 07Research also shows glycolic acid stimulates collagen production, helping to firm and thicken the skin over time. This is one of its biggest advantages over other AHAs.
  8. 08Overall, glycolic acid helps with:
  9. 09Fun fact: Glycolic acid boosts skin hydration by helping it produce molecules that increase hyaluronic acid naturally.
  10. 10To work best, glycolic acid products should have a pH between 3-4 (that’s where exfoliation is most effective but still gentle on skin).
  11. 11The pH and concentration of a product are key to its effectiveness:
  12. 12It is normal to feel a slight stinging sensation when using glycolic acid. This usually fades as your skin adjusts.
  13. 13Because glycolic acid has the smallest molecular size in the AHA family, it can penetrate deeper, which enhances its effectiveness but also makes it more likely to irritate sensitive skin.
  14. 14If your skin is very sensitive or prone to rosacea, glycolic acid may be too strong; in that case, try milder options like lactic acid or a PHA instead.
  15. 15Recent studies suggest glycolic acid might even help protect against UV damage. But don’t skip sunscreen! Freshly exfoliated skin is more sensitive to the sun.
  16. 16Glycolic acid is a skincare superstar. It smooths, brightens, hydrates, and firms the skin. Unless you’re highly sensitive, it’s well worth adding to your routine.
  17. 17Read more about some other popular AHA's here:
  18. 18Propylene 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.
  19. 19As 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.
  20. 20The CIR Expert Panel has confirmed this ingredient to be nontoxic and clinical studies show no sensitization at cosmetic use concentrations.
Source · skinsort.com
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Product index

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Comparison edit

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