Peptide Skincare & BeautySkin science and ingredient guides

Skin science article

Paula's Choice Pro-Collagen Multi-Peptide Booster Versus Peter Thomas Roth Peptide 21 Wrinkle Resist Serum

Paula's Choice Pro-Collagen Multi-Peptide Booster Versus Peter Thomas Roth Peptide 21 Wrinkle Resist Serum This anti-aging serum is formulated around Tripeptide-10 Citrulline and Acetyl Octapeptide-3 to soften the look of wrinkles. What's inside Key Ingredient

Paula's Choice Pro-Collagen Multi-Peptide Booster Versus Peter Thomas Roth Peptide 21 Wrinkle Resist Serum

This anti-aging serum is formulated around Tripeptide-10 Citrulline and Acetyl Octapeptide-3 to soften the look of wrinkles.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Glycerin

Pentylene Glycol

Hydrolyzed Yeast Extract

Pyrus Malus Fruit Extract

Dimethicone

Propanediol

Ceramide AP

1,2-Hexanediol

Glyceryl Glucoside

Palmitoyl Tetrapeptide-72 Amide

Sh-Polypeptide-121

Tridecapeptide-1

Polyglucuronic Acid

Sodium Hyaluronate

C9-12 Alkane

Ammonium Polyacryloyldimethyl Taurate

Polygonum Bistorta Root Extract

Bacillus Ferment

Lecithin

Sodium Phytate

Coco-Caprylate/Caprate

Hexylene Glycol

Cetyl Hydroxyethylcellulose

Xanthan Gum

Ethylhexylglycerin

Caprylyl Glycol

Magnesium Chloride

Potassium Sorbate

Sodium Benzoate

Water, Glycerin, Pentylene Glycol, Hydrolyzed Yeast Extract, Pyrus Malus Fruit Extract, Dimethicone, Propanediol, Ceramide AP, 1,2-Hexanediol, Glyceryl Glucoside, Palmitoyl Tetrapeptide-72 Amide, Sh-Polypeptide-121, Tridecapeptide-1, Polyglucuronic Acid, Sodium Hyaluronate, C9-12 Alkane, Ammonium Polyacryloyldimethyl Taurate, Polygonum Bistorta Root Extract, Bacillus Ferment, Lecithin, Sodium Phytate, Coco-Caprylate/Caprate, Hexylene Glycol, Cetyl Hydroxyethylcellulose, Xanthan Gum, Ethylhexylglycerin, Caprylyl Glycol, Magnesium Chloride, Potassium Sorbate, Sodium Benzoate

Rosa Centifolia Flower Water

Isopropyl Myristate

Squalane

Mannitol

Butylene Glycol

Natto Gum

Tripeptide-10 Citrulline

Acetyl Octapeptide-3

Palmitoyl Hexapeptide-12

Acetyl Tetrapeptide-11

Acetyl Hexapeptide-8

Acetyl Hexapeptide-1

Palmitoyl Oligopeptide

Acetyl Tetrapeptide-9

Acetyl Tetrapeptide-2

Tripeptide-1

Palmitoyl Tetrapeptide-7

Hexapeptide-11

Dipeptide Diaminobutyroyl Benzylamide Diacetate

Palmitoyl Tripeptide-5

Trifluoroacetyl Tripeptide-2

Palmitoyl Tripeptide-1

Sodium Polyglutamate

Tocopheryl Acetate

Retinyl Palmitate

Ascorbic Acid

Hydrolyzed Soy Protein

Hydrolyzed Wheat Protein

Pseudoalteromonas Ferment Extract

Acrylates Copolymer

Polysorbate 20

Dimethyl Isosorbide

Acrylates/C10-30 Alkyl Acrylate Crosspolymer

Leuconostoc/Radish Root Ferment Filtrate

PEG-8 Dimethicone

Disodium Phosphate

Carbomer

Dextran

Sodium Lactate

Tetradecyl Aminobutyroylvalylaminobutyric Urea Trifluoroacetate

Triethanolamine

Sodium Phosphate

Octyldodecanol

Silica

Sodium Propoxyhydroxypropyl Thiosulfate Silica

Sodium Hydroxide

Phenoxyethanol

Water, Glycerin, Rosa Centifolia Flower Water, Isopropyl Myristate, Squalane, Mannitol, Butylene Glycol, Natto Gum, Tripeptide-10 Citrulline, Acetyl Octapeptide-3, Palmitoyl Hexapeptide-12, Acetyl Tetrapeptide-11, Acetyl Hexapeptide-8, Acetyl Hexapeptide-1, Palmitoyl Oligopeptide, Acetyl Tetrapeptide-9, Acetyl Tetrapeptide-2, Tripeptide-1, Palmitoyl Tetrapeptide-7, Hexapeptide-11, Dipeptide Diaminobutyroyl Benzylamide Diacetate, Palmitoyl Tripeptide-5, Trifluoroacetyl Tripeptide-2, Palmitoyl Tripeptide-1, Sodium Polyglutamate, Sodium Hyaluronate, Tocopheryl Acetate, Retinyl Palmitate, Ascorbic Acid, Hydrolyzed Soy Protein, Hydrolyzed Wheat Protein, Lecithin, Pseudoalteromonas Ferment Extract, Acrylates Copolymer, Magnesium Chloride, Polysorbate 20, Dimethyl Isosorbide, Acrylates/C10-30 Alkyl Acrylate Crosspolymer, Leuconostoc/Radish Root Ferment Filtrate, PEG-8 Dimethicone, Disodium Phosphate, Carbomer, Dextran, Sodium Lactate, Tetradecyl Aminobutyroylvalylaminobutyric Urea Trifluoroacetate, Xanthan Gum, Triethanolamine, Sodium Phosphate, Octyldodecanol, Silica, Sodium Propoxyhydroxypropyl Thiosulfate Silica, Sodium Hydroxide, Caprylyl Glycol, Potassium Sorbate, Sodium Benzoate, Phenoxyethanol

Reviews

Be the first to review

Alternatives

Ingredients Explained

These ingredients are found in both products.

Ingredients higher up in an ingredient list are typically present in a larger amount.

Caprylyl Glycol is a humectant, skin conditioner, emollient, and preservative booster derived from either caprylic acid or synthetically created.

Typical use levels vary from 0.3-1% as a preservative booster and go up to 2% to condition skin.

Because it is not a free-fatty acid, this ingredient is fungal acne safe (there's nothing for Malassezia to feed on).

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.

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.

Magnesium chloride is a mineral salt made from magnesium and chloride. It is mainly used to control product stability and texture in cosmetics.

This ingredient can also play a role in soothing the skin and supporting normal skin function.

Magnesium chloride is water-soluble, generally well tolerated, and does not act as a strong “active” ingredient on its own.

Potassium Sorbate is a preservative used to prevent yeast and mold in products. It is commonly found in both cosmetic and food products.

This ingredient comes from potassium salt derived from sorbic acid. Sorbic acid is a natural antibiotic and effective against fungus.

Both potassium sorbate and sorbic acid can be found in baked goods, cheeses, dried meats, dried fruit, ice cream, pickles, wine, yogurt, and more.

You'll often find this ingredient used with other preservatives.

Sodium Benzoate is a preservative. It's used in both cosmetic and food products to inhibit the growth of mold and bacteria. It is typically produced synthetically.

Both the US FDA and EU Health Committee have approved the use of sodium benzoate. In the US, levels of 0.1% (of the total product) are allowed.

Sodium benzoate works as a preservative by inhibiting the growth of bacteria inside of cells. It prevents the cell from fermenting a type of sugar using an enzyme called phosphofructokinase.

It is the salt of benzoic acid. Foods containing sodium benzoate include soda, salad dressings, condiments, fruit juices, wines, and snack foods.

Studies for using ascorbic acid and sodium benzoate in cosmetics are lacking, especially in skincare routines with multiple steps.

We always recommend speaking with a professional, such as a dermatologist, if you have any concerns.

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.

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. 03Octyldodecanol is a fatty alcohol sourced from plant oils like coconut or palm (or made synthetically).
  4. 04It is:
  5. 05You'll likely see this in many BHA products because this is the go-to solvent for salicylic acid.
  6. 06This ingredient is typically used at levels between 2-20%.
  7. 07Regarding fungal acne: In 2019, this ingredient was tested against multiple Malassezia species (the yeast that causes fungal acne) and showed no growth.
  8. 08Palmitoyl Tripeptide-1 (aka Pal-GHK) is a synthetic signal peptide made of three amino acids attached to palmitic acid.
  9. 09That 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.
  10. 10Once there, it acts as a matrikine, a signaling peptide that prompts fibroblasts to produce more collagen, fibronectin, and hyaluronic acid.
  11. 11In 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…
  12. 12Human clinical data is promising, but modest:
  13. 13A study of 23 female volunteers found a small but statistically significant increase (~4%) in skin thickness after treatment at 4 ppm.
  14. 14A 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.
  15. 15You'll likely see Pal-GHK paired with Palmitoyl Tetrapeptide-7 as part of the Matrixyl 3000 complex.
  16. 16Fungal 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.
  17. 17Tocopheryl Acetate is a stable, shelf-friendly form of vitamin E.
  18. 18Formulators love it because plain vitamin E oxidizes quickly once it hits air. This acetate version stays stable and resists going off, helping to extend a product's shelf life.
  19. 19It's actually inactive on its own and works like a slow-release "storage" form; the enzymes in your skin called esterases gradually convert it into active vitamin E over time.
  20. 20One in vivo study showed 5% of the acetate in the living layer of the epidermis converted to vitamin E after 5 days of application. This study also found the skin gained protection against UV damage even though the conversion was slow and small.
Source · skinsort.com
02

Product index

Related product references

03

Comparison edit

Read side by side