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Paula's Choice Skin Perfecting 25% AHA + 2% BHA Exfoliant Peel Versus Allies of Skin Multi Acids & Retinoid Brightening Sleeping Facial

Paula's Choice Skin Perfecting 25% AHA + 2% BHA Exfoliant Peel Versus Allies of Skin Multi Acids & Retinoid Brightening Sleeping Facial This smoothing exfoliator is formulated around Glycolic Acid and Lactic Acid to refine skin texture and brighten dull-lookin

Paula's Choice Skin Perfecting 25% AHA + 2% BHA Exfoliant Peel Versus Allies of Skin Multi Acids & Retinoid Brightening Sleeping Facial

This smoothing exfoliator is formulated around Glycolic Acid and Lactic Acid to refine skin texture and brighten dull-looking skin.

This smoothing overnight mask is formulated around Glycolic Acid and Niacinamide to refine skin texture and brighten dull-looking skin.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Aminomethyl Propanol

Glycolic Acid

Lactic Acid

Mandelic Acid

Isoamyl Laurate

Tartaric Acid

Propanediol

Salicylic Acid

Malic Acid

Butylene Glycol

Clitoria Ternatea Flower Extract

Sodium Hyaluronate

Glycyrrhetinic Acid

Glycerin

Tocopherol

Bisabolol

Allantoin

Hydroxyethylcellulose

Hydrogenated Lecithin

Xanthan Gum

Polyglyceryl-4 Laurate

Polyacrylate Crosspolymer-6

Titanium Dioxide

Mica

Phenoxyethanol

Water, Aminomethyl Propanol, Glycolic Acid, Lactic Acid, Mandelic Acid, Isoamyl Laurate, Tartaric Acid, Propanediol, Salicylic Acid, Malic Acid, Butylene Glycol, Clitoria Ternatea Flower Extract, Sodium Hyaluronate, Glycyrrhetinic Acid, Glycerin, Tocopherol, Bisabolol, Allantoin, Hydroxyethylcellulose, Hydrogenated Lecithin, Xanthan Gum, Polyglyceryl-4 Laurate, Polyacrylate Crosspolymer-6, Titanium Dioxide, Mica, Phenoxyethanol

Polysorbate 20

Niacinamide

Hydrolyzed Silk

Sodium Hydroxide

Yogurt

Caprylyl Glycol

Dimethyl Isosorbide

Saccharomyces/Xylinum/Black Tea Ferment

Mel

Honey Extract

Panthenol

Glycyrrhiza Glabra Root Extract

Sodium Hyaluronate Crosspolymer-3

Physalis Angulata Extract

Galactoarabinan

Globularia Alypum Leaf Extract

Dimethyl Sulfone

Zymomonas Ferment Extract

Polygonum Cuspidatum Extract

Hydrolyzed Opuntia Ficus-Indica Flower Extract

Ascophyllum Nodosum Extract

Mirabilis Jalapa Flower/Leaf/Stem Extract

Diglucosyl Gallic Acid

Hydroxypinacolone Retinoate

Rosmarinyl Glucoside

Caffeyl Glucoside

Gallyl Glucoside

Caprylic/Capric Triglyceride

Sodium Lactate

Sodium Gluconate

Maltodextrin

Sclerotium Gum

Ethylhexylglycerin

Glyceryl Acrylate/Acrylic Acid Copolymer

Tetrasodium EDTA

Water, Glycerin, Glycolic Acid, Polysorbate 20, Propanediol, Niacinamide, Butylene Glycol, Hydrolyzed Silk, Sodium Hydroxide, Yogurt, Lactic Acid, Salicylic Acid, Caprylyl Glycol, Polyacrylate Crosspolymer-6, Dimethyl Isosorbide, Saccharomyces/Xylinum/Black Tea Ferment, Mel, Honey Extract, Panthenol, Allantoin, Glycyrrhiza Glabra Root Extract, Sodium Hyaluronate, Sodium Hyaluronate Crosspolymer-3, Physalis Angulata Extract, Galactoarabinan, Globularia Alypum Leaf Extract, Dimethyl Sulfone, Zymomonas Ferment Extract, Polygonum Cuspidatum Extract, Hydrolyzed Opuntia Ficus-Indica Flower Extract, Ascophyllum Nodosum Extract, Mirabilis Jalapa Flower/Leaf/Stem Extract, Diglucosyl Gallic Acid, Bisabolol, Hydroxypinacolone Retinoate, Rosmarinyl Glucoside, Caffeyl Glucoside, Gallyl Glucoside, Caprylic/Capric Triglyceride, Sodium Lactate, Sodium Gluconate, Maltodextrin, Sclerotium Gum, Xanthan Gum, Ethylhexylglycerin, Hydroxyethylcellulose, Glyceryl Acrylate/Acrylic Acid Copolymer, Tetrasodium EDTA, Phenoxyethanol

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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.

Allantoin is a soothing ingredient known for its protective and moisturizing properties; it's basically a quiet workhorse ingredient you can find in a huge range of cosmetics.

Though it can be derived from the comfrey plant, allantoin is produced synthetically for cosmetic products to ensure purity.

Research shows it can encourage your skin cells to turn over and renew by stimulating keratinocyte and fibroblast proliferation.

It also has mild keratolytic properties to help loosen and shed dead skin cells without being harsh.

Studies also suggest allantoin can help calm inflammation by dialing down some of the chemical signals your skin sends out when it is irritated.

This ingredient is typically used in the 0.1-0.5% range, and the FDA recognizes it as a skin protectant in OTC products up to 2%.

Overall, allantoin is a wonderful addition to most routines; it is stable across a wide pH range (~4-8), works well with other ingredients, and is considered non-sensitizing/non-irritating.

Fun fact: Allantoin is naturally occurring in comfrey root, beets, chamomile, and wheat sprouts. Our bodies even produce it as a byproduct of uric acid metabolism.

Bisabolol is a gentle skin conditioner, antioxidant, and soothing ingredient.

It's primary claim to fame is soothing and research shows topically applied bisabolol can quiet the chemical messengers that cause your skin to become inflamed, helping to sooth any irritation.

A clinical study found that applying 0.5% bisabolol daily for 8 weeks produced an average 9% decrease in skin pigmentation. Researchers found it can also suppress the process that leads to excess melanin production in skin.

In vitro studies found that bisabolol combined with propylene glycol significantly increased skin permeability by increasing lipid fluidity in the stratum corneum.

You'll likely see use concentrations quite low, usually 0.1-0.2%.

Overall, this is a well-tolerated ingredient that works well in formulas designed for sensitive, reactive, or post-procedure skin.

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.

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.

Glycolic Acid is arguably the most famous alpha hydroxy acid (AHA) with tons of research backing its benefits.

It is found naturally in sugar cane but the form used in skincare is usually synthetic for purity and stability.

Glycolic acid removes the top layer of dead skin cells to allow newer and fresher ones to emerge.

AHAs 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.

Research 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.

Overall, glycolic acid helps with:

Fun fact: Glycolic acid boosts skin hydration by helping it produce molecules that increase hyaluronic acid naturally.

To work best, glycolic acid products should have a pH between 3-4 (that’s where exfoliation is most effective but still gentle on skin).

The pH and concentration of a product are key to its effectiveness:

It is normal to feel a slight stinging sensation when using glycolic acid. This usually fades as your skin adjusts.

Because 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.

If 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.

Recent 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.

Glycolic 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.

Read more about some other popular AHA's here:

Hydroxyethylcellulose is used to improve the texture of products. It is created from a chemical reaction involving ethylene oxide and alkali-cellulose. Cellulose is a sugar found in plant cell walls and help give plants structure.

This ingredient helps stabilize products by preventing ingredients from separating. It can also help thicken the texture of a product.

This ingredient can also be found in pill medicines to help our bodies digest other ingredients.

Lactic Acid is another well-loved alpha hydroxy acid (AHA). It is gentler than glycolic acid but still highly effective.

Its main role is to exfoliate the surface of the skin by loosening the “glue” that holds dead skin cells together. Shedding those old cells leads to smoother, softer, and more even-toned skin.

Because lactic acid molecules are larger than glycolic acid, they don’t penetrate as deeply. This means they’re less likely to sting or irritate, making it a great choice for beginners or those with sensitive skin.

Like glycolic acid, it can:

Lactic acid also acts as a humectant (like hyaluronic acid). It can draw water into the skin to improve hydration and also plays a role in the skin's natural moisturizing factor (NMF) in the form of sodium lactate.

Studies show it can boost ceramide production to strengthen the skin barrier and even help balance the skin’s microbiome.

To get results, choose products with a pH between 3-4.

Lower strengths (5-12%) focus on surface exfoliation; higher strengths (12% and up) can reach deeper in the dermis (deeper, supportive layer) to improve skin texture and firmness over time.

Though it was originally derived from milk, most modern lactic acid used in skincare is vegan. It is made through non-dairy fermentation to create a bio-identical and stable form suitable for all formulations.

When lactic acid shows up near the end of an ingredient list, it usually means the brand added just a tiny amount to adjust the product’s pH.

Legend has it that Cleopatra used to bathe in sour milk to help reduce wrinkles.

Lactic acid is truly a gentle multitasker: it exfoliates, hydrates, strengthens, and brightens. It's a great ingredient for giving your skin a smooth, glowing, and healthy look without the harshness of stronger acids.

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.

Polyacrylate Crosspolymer-6 is a texture enhancer and pH adjuster.

It is be used to thicken water-based products and create a gel-texture with a velvet feel.

One manufacturer claims this ingredient to have a pH range of 2-8 and to be biodegradable.

This ingredient is also known as Sepimax Zen.

Propanediol is an all-star ingredient. It softens, hydrates, and smooths the skin.

It’s often used to:

Propanediol is not likely to cause sensitivity and considered safe to use. It is derived from corn or petroleum with a clear color and no scent.

Salicylic Acid (also known as beta hydroxy acid or BHA) is a well-known ingredient for treating skin that struggles with acne and clogged pores. It exfoliates both the skin's surface and deep within the pores to help clear out buildup, control oil, and reduce inflammation.

Unlike AHAs (alpha hydroxy acids), salicylic acid is oil-soluble. This allows it to penetrate into pores which makes it especially effective for treating blackheads and preventing future breakouts.

Salicylic acid is also known for its soothing properties. It has a similar structure to aspirin and can calm inflamed or irritated skin, making it a good option for acne-prone skin that is also sensitive.

Concentrations of 0.5-2% are recognized by the U.S. FDA as an over-the-counter topical acne product.

It can cause irritation and/or dryness if one's skin already has a compromised moisture barrier, so it's best to focus on repairing that before introducing this ingredient into your routine.

While salicylic acid does not increase sun sensitivity, it’s still important to wear sunscreen daily to protect your skin.

If you are looking for the ingredient called BHA or Butylated Hydroxyanisole, click here.

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.

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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. 06Ethylhexylglycerin is created from glycerin. It is a multitasker ingredient that:
  7. 07The CIR Expert Panel found minimal skin absorption or sensitization of any kind in a safety assessment. Though this ingredient is considered well-tolerated, a small number of cases of allergic dermatitis have been published since 2002. Just be sure …
  8. 08Industry-reported use ranges from 8% in rinse-off products and 2% in leave-on formulations.
  9. 09Glycerin (or glycerol) is a compound naturally found in your skin. It's a powerhouse humectant that pulls water into the stratum corneum.
  10. 10Topically, glycerin does several things at once:
  11. 11Your 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.
  12. 12Aquaporin-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.
  13. 13This 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.
  14. 14Just know very high concentrations (>40%) can feel tacky in low humidity.
  15. 15Glycerin is the name for this ingredient in American English. British English uses Glycerol/Glycerine.
  16. 16Lecithin is a term for a group of substances found in the cell membranes of plants, animals, and humans. They are made up of phospholipids.
  17. 17Thanks to its amphiphilic structure (water-loving head and oil-loving tail), it is a true multitasker:
  18. 18It plays well with most ingredients and is typically used at 0.1-1%. However, concentrations up to 50% have been reported in moisturizers.
  19. 19Niacinamide is a multitasking form of vitamin B3 that strengthens the skin barrier, reduces pores and dark spots, regulates oil, and improves signs of aging.
  20. 20And the best part? It's gentle and well-tolerated by most skin types, including sensitive and reactive skin.
Source · skinsort.com
02

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03

Comparison edit

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