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Skin science article

Creamy Retinol Versus Paula's Choice 1% Retinol Treatment

Creamy Retinol Versus Paula's Choice 1% Retinol Treatment This anti-aging serum is formulated around Retinol and Alpha-Arbutin to soften the look of wrinkles and fade the look of dark spots. This anti-aging treatment is formulated around Retinol and Tetrahexyl

Creamy Retinol Versus Paula's Choice 1% Retinol Treatment

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

This anti-aging treatment is formulated around Retinol and Tetrahexyldecyl Ascorbate to soften the look of wrinkles and refine skin texture.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Retinol

Alpha-Arbutin

Butylene Glycol

Ascorbyl Palmitate

Sodium Hyaluronate

Sodium Acrylates Copolymer

Xanthan Gum

Glycerin

Linoleic Acid

Lecithin

Linolenic Acid

Arachidonic Acid

Azelamidopropyl Dimethyl Amine

Palmitoyl Tripeptide-1

Palmitoyl Hexapeptide-12

Hydroxyethylcellulose

Phloretin

Tocopherol

Ferulic Acid

BHA

BHT

Ethoxydiglycol

Disodium EDTA

Bisabolol

Polysorbate 80

Dehydroacetic Acid

Benzoic Acid

Polysorbate 20

Benzyl Alcohol

Phenoxyethanol

Poloxamer 407

Ethylhexylglycerin

Water, Retinol, Alpha-Arbutin, Butylene Glycol, Ascorbyl Palmitate, Sodium Hyaluronate, Sodium Acrylates Copolymer, Xanthan Gum, Glycerin, Linoleic Acid, Lecithin, Linolenic Acid, Arachidonic Acid, Azelamidopropyl Dimethyl Amine, Palmitoyl Tripeptide-1, Palmitoyl Hexapeptide-12, Hydroxyethylcellulose, Phloretin, Tocopherol, Ferulic Acid, BHA, BHT, Ethoxydiglycol, Disodium EDTA, Bisabolol, Polysorbate 80, Dehydroacetic Acid, Benzoic Acid, Polysorbate 20, Benzyl Alcohol, Phenoxyethanol, Poloxamer 407, Ethylhexylglycerin

Dimethicone

Isononyl Isononanoate

Castor Isostearate Succinate

Glyceryl Stearate

C12-15 Alkyl Benzoate

Dimethicone Crosspolymer

PEG-33

Behenyl Alcohol

PEG-100 Stearate

Pentaerythrityl Tetraisostearate

Polymethylsilsesquioxane

Tetrahexyldecyl Ascorbate

Ceramide Ng

Palmitoyl Tetrapeptide-7

Dipotassium Glycyrrhizate

Glycyrrhiza Glabra Root Extract

Avena Sativa Kernel Extract

Arctium Lappa Seed Oil

Salix Alba Extract

Glycine Soja Sterols

Allantoin

Tocopheryl Acetate

Hydrolyzed Soy Protein

Sorbitan Laurate

Acetyl Dipeptide-1 Cetyl Ester

Sodium Hydroxide

Tribehenin

Caprylyl Glycol

Pentylene Glycol

PEG-75 Shea Butter Glycerides

PPG-12/Smdi Copolymer

PEG-10 Phytosterol

PEG-8 Dimethicone

PEG-14

Magnesium Aluminum Silicate

Arachidyl Glucoside

Arachidyl Alcohol

Sclerotium Gum

Carbomer

Water, Dimethicone, Glycerin, Butylene Glycol, Isononyl Isononanoate, Castor Isostearate Succinate, Glyceryl Stearate, C12-15 Alkyl Benzoate, Dimethicone Crosspolymer, PEG-33, Polysorbate 20, Behenyl Alcohol, PEG-100 Stearate, Pentaerythrityl Tetraisostearate, Polymethylsilsesquioxane, Tetrahexyldecyl Ascorbate, Retinol, Ceramide Ng, Palmitoyl Tetrapeptide-7, Palmitoyl Hexapeptide-12, Sodium Hyaluronate, Dipotassium Glycyrrhizate, Glycyrrhiza Glabra Root Extract, Avena Sativa Kernel Extract, Arctium Lappa Seed Oil, Salix Alba Extract, Glycine Soja Sterols, Lecithin, Allantoin, Tocopheryl Acetate, Hydrolyzed Soy Protein, Sorbitan Laurate, Acetyl Dipeptide-1 Cetyl Ester, Disodium EDTA, Hydroxyethylcellulose, Palmitoyl Tripeptide-1, Sodium Hydroxide, Tribehenin, Caprylyl Glycol, Ethylhexylglycerin, Pentylene Glycol, PEG-75 Shea Butter Glycerides, PPG-12/Smdi Copolymer, PEG-10 Phytosterol, PEG-8 Dimethicone, PEG-14, Magnesium Aluminum Silicate, Arachidyl Glucoside, Arachidyl Alcohol, Sclerotium Gum, Carbomer, Phenoxyethanol, Benzoic Acid

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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.

Benzoic Acid is an organic acid that shows up in cosmetics as a preservative. It helps keep a product from spoiling by holding back the growth of yeast, mold, and some bacteria.

This ingredient also functions as a fragrance ingredient that helps mask the unpleasant scent of other ingredients.

The way it works is worth understanding; benzoic acid works when the formula is acidic. It is able to sneak into a microbe's cell and mess up how it functions to stop it from growing in an acidic product.

However, the acid switches to an inactive form and stops working if a product isn't acidic enough (above ~5 pH). This is why you'll often see it in low pH products or teamed up with other preservatives to cover the gap.

Safety wise, it's one of the better studied preservatives out there.

The Cosmetic Ingredient Review Expert Panel has concluded this ingredient to be safe for use in cosmetic formulations at concentrations up to 5%.

A large international review found this ingredient had no effects on the human body and had low irritation potential.

Just so you know, real world use is usually much lower than the 5% ceiling (usually 1% of less).

The EU caps it at 2.5% in rinse-off products, 1.7% in oral care, and 0.5% in leave-on products.

One thing worth mentioning (it's nothing to worry about): some people get a little stinging or flushing where they apply it. This isn't a true allergy; it's a temporary and harmless reaction. This is the same kind of mild tingle you might notice from sorbic acid.

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.

Disodium EDTA is a chelating agent. It grabs onto and deactivates metal ions that sneak into your products from water, packaging, or air.

This ingredient mainly works behind the scenes and helps with:

On top of that, this ingredient can counteract the effects of hard water by binding to the minerals in it.

One thing worth knowing is that Disodium EDTA has been shown to be a mild penetration enhancer. It can help other ingredients absorb into skin more effectively which can be a double-edged sword (great for actives, but can also make the active too strong if you have sensitive skin).

Clinical patch testing showed no significant skin irritation at typical use concentrations and minimal dermal absorption.

You'll most likely see this ingredient near the end of an ingredient list. It's typically found in concentrations less than 1%.

Ethylhexylglycerin is created from glycerin. It is a multitasker ingredient that:

The 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 to patch test if you are unsure.

Industry-reported use ranges from 8% in rinse-off products and 2% in leave-on formulations.

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.

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.

Lecithin is a term for a group of substances found in the cell membranes of plants, animals, and humans. They are made up of phospholipids.

Thanks to its amphiphilic structure (water-loving head and oil-loving tail), it is a true multitasker:

It plays well with most ingredients and is typically used at 0.1-1%. However, concentrations up to 50% have been reported in moisturizers.

Palmitoyl Hexapeptide-12 is a synthetic lipopeptide. This just means it's a short chain of six amino acids with a palmitic acid molecule attached to one end.

The palmitoyl group increases the lipophilicity, helping it penetrate the lipid-rich outer layer of skin more effectively.

Once inside, it helps with keeping skin springy and firm. It works by mimicking the skin repair signals your skin naturally sends out when it's damaged and telling it to kick into rebuild mode.

Studies have shown it can help strengthen the skin barrier as well so it's useful beyond just anti-aging.

In vitro studies suggest it can switch on genes that help skin cells grow, move around, and rebuild skin structure. Just keep in mind most of the strong evidence is from lab studies rather than large-scale clinical trials.

Lab studies suggest it can switch on genes that help skin cells grow, move around, and rebuild skin structure.

This ingredient is usually used at very low concentrations (0.002% in leave-on products).

Fungal acne note: Usually a palmitic acid component can feed Malassezia in unbound form, but here is is covalently bonded to the peptide. This means it is very difficult for Malassezia to access, and therefore very unlikely to cause fungal acne.

Palmitoyl Tripeptide-1 (aka Pal-GHK) is a synthetic signal peptide made of three amino acids attached to palmitic acid.

That fatty acid attachment is the key: it boosts the peptide's ability to penetrate the skin barrier. This puts it closer to the dermal cells where it can actually make a difference.

Once there, it acts as a matrikine, a signaling peptide that prompts fibroblasts to produce more collagen, fibronectin, and hyaluronic acid.

In vitro studies show it can boost collagen production in skin cells even when UV-damaged skin samples were treated with it at a tiny concentration (it almost fully restored dermal collagen at 5ppm). It achieved this at 100x lower concentration than retinoic acid, which needed 500 ppm to do the same thing.

Human clinical data is promising, but modest:

A study of 23 female volunteers found a small but statistically significant increase (~4%) in skin thickness after treatment at 4 ppm.

A separate small trial of 15 women showed statistically significant reductions in wrinkle length, depth, and skin roughness after applying it twice daily for four weeks.

You'll likely see Pal-GHK paired with Palmitoyl Tetrapeptide-7 as part of the Matrixyl 3000 complex.

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.

Polysorbate 20 is a gentle, water-soluble emulsifier and mild surfactant. It stops oil and water from separating to keep your formulas blended and stable.

It also acts as a mild penetration enhancer by helping active ingredients absorb slightly better.

The common safety discussion around this ingredient involves a manufacturing byproduct called 1,4-dioxane.

Trace amounts can form during production but the EU's Scientific Committee on Consumer Safety has concluded that levels at/below 10 ppm in finished products are safe (commercial products consistently fall within acceptable margins).

True allergic reactions are uncommon and the CIR Expert Panel has confirmed this ingredient to be safe as used in cosmetics.

Because it is derived from lauric acid, it may not be fungal acne safe.

Retinol is one of the most studied anti-aging ingredients in skincare (and for good reason!).

It's a form of vitamin A that your skin converts into Retinoic Acid, the active molecule that actually does the work in your cells.

That conversion happens in two steps: your skin first turns Retinol into Retinaldehyde (also called Retinal), then turns Retinaldehyde into Retinoic Acid.

Retinol is converted to biologically active retinoic acid via retinaldehyde by dehydrogenases in a two-step oxidation process.

Each step is a little "upgrade" toward the active form which is part of why Retinol is gentler than prescription Retinoic Acid; your skin does the work gradually. This also explains where Retinol sits in the retinoid family.

Here is the retinoid family ranked roughly by strength: Retinyl Esters (like Retinyl Palmitate) < Retinol < Retinaldehyde < Retinoic Acid.

Retinoid activity increases in that order, while tolerance runs in reverse; retinyl esters are the gentlest and retinoic acid the most irritating.

The more conversion steps an ingredient needs, the gentler (and slower) it tends to be, so Retinol lands in a nice middle spot. It's more effective than the esters, gentler than prescription options.

Once it becomes Retinoic Acid, it binds to receptors inside your cells' nuclei (called RARs and RXRs). These receptor pairs bind to specific DNA motifs called retinoic acid response elements and act like switches that turn certain genes on or off.

In practice, this means a few things happen in a formula. It:

That last two are worth a closer look.

A study that tested Retinol directly (not just prescription Retinoic Acid) found that four weeks of retinol thickened the epidermis and switched on the genes for Collagen I and Collagen III, with more procollagen I and III showing up in the skin. And after twelve weeks, facial wrinkles were visibly reduced.

Retinoids more broadly stimulate the skin's synthesis of hyaluronan and other glycosaminoglycans, part of what gives skin a plumper, more hydrated look over time.

So even the gentler OTC form is doing real structural work (not just sitting on the surface).

It's also worth knowing Retinol isn't only a wrinkle ingredient; it can help with uneven tone, dark spots, rough texture, and the look of pores as well because it speeds up turnover and influences pigment.

The research backs this up as well.

A pooled analysis of six clinical studies found that 0.1% stabilized retinol improved all signs of photoaging versus vehicle as early as week 4 and through 12 weeks, with only a few mild cases of irritation.

Another study comparing concentrations found that 0.3% and 1% Retinol were similarly effective at remodeling photodamaged skin, but 0.3% caused fewer adverse reactions when used daily (a useful reminder that more isn't always better).

Retinol is about tenfold less potent than Retinoic Acid. This is why it works as a gentler, non-prescription option that builds results over time.

Typical concentrations range from 0.1-1%, with 0.1% to 0.3% being a well-supported sweet spot for visible benefits with good tolerability.

One quirk worth mentioning: Retinol is famously unstable.

It's highly sensitive to light and oxygen, and UV exposure breaks it down into a range of degradation products.

Real-world testing bears this out, with retinoid content in some products dropping anywhere from 0% to 80% after six months at room temperature, and even more at higher temperatures.

This is why good formulations lean on opaque, air-tight packaging (think tubes and pumps, not clear jars) and often "encapsulate" the Retinol to shield it.

Signs of oxidation include your product turning yellow or smelling "off". Keeping it somewhere cool and dark, and using it up within a few months of opening helps it stay effective.

The most common side effects are mild and temporary: usually some dryness, redness, or light peeling as your skin adjusts. These tend to settle with consistent and lower-frequency use.

Like all retinoids, Retinol works best with nightly use, a good moisturizer, and daytime sunscreen.

The "ramp up" method works well: start with Retinol once a week to give your skin time to adjust, which keeps irritation low. Slowly add more nights until you reach your goal frequency once your skin feels comfortable.

Retinoids also make your skin more sensitive to the sun in the first few weeks, so wear sunscreen every morning and protect your skin from direct sun while you build up tolerance.

One safety note: topical Retinoids aren't recommended during pregnancy or breastfeeding. Systemic absorption from creams is low but because high oral vitamin A is a known teratogen and topical safety data are limited, most clinicians recommend stopping retinoids when pregnant or trying to conceive.

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!

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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. 03Citric Acid is an alpha hydroxy acid (AHA) naturally found in citrus fruits like oranges, lemons, and limes.
  4. 04Like 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.
  5. 05However, this exfoliating effect only happens at high concentrations (20%) which can be hard to find in cosmetic products.
  6. 06Due 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.
  7. 07In skincare formulas, citric acid can:
  8. 08While it can provide some skin benefits, research shows lactic acid and glycolic acid are generally more effective and less irritating exfoliants.
  9. 09Most 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.
  10. 10Rosacea 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.
  11. 11However, 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…
  12. 12Mandelic Acid is an alpha hydroxy acid (AHA).
  13. 13Like other AHAs, it helps exfoliate the surface of the skin by breaking down the bonds that hold dead skin cells together. This helps reveal smoother and brighter skin underneath.
  14. 14Mandelic acid helps with:
  15. 15Due to it having a larger molecular size than glycolic acid, mandelic acid is able to penetrate the skin more slowly and evenly. This makes it gentler and less irritating, making it a great option for sensitive or beginner skin.
  16. 16Despite being milder, mandelic acid is still an effective exfoliant that improves skin texture and tone over time.
  17. 17What makes mandelic acid stand out from other AHAs? It has antibacterial and antioxidant properties.
  18. 18These traits make it a great option for acne-prone or problem skin by reducing active breakouts and fading post-acne marks. Studies show that mandelic acid (especially when combined with salicylic acid) can significantly reduce pimples and hyperpigm…
  19. 19Mandelic acid is effective in concentrations of 5% and up with an ideal pH range of 3-4 for at-home use.
  20. 20Like other AHAs, it’s important to wear sunscreen daily to protect your newly exfoliated skin.
Source · skinsort.com
02

Product index

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03

Comparison edit

Read side by side