Peptide Skincare & BeautySkin science and ingredient guides

Skin science article

Carrot & Stick The Repair Serum Versus Peter Thomas Roth Peptide 21 Wrinkle Resist Serum

Carrot & Stick The Repair Serum Versus Peter Thomas Roth Peptide 21 Wrinkle Resist Serum This barrier-repair serum is formulated around Niacinamide and Sh-Oligopeptide-1 to strengthen the skin barrier and soften the look of wrinkles. This anti-aging serum is f

Carrot & Stick The Repair Serum Versus Peter Thomas Roth Peptide 21 Wrinkle Resist Serum

This barrier-repair serum is formulated around Niacinamide and Sh-Oligopeptide-1 to strengthen the skin barrier and soften the look of wrinkles.

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

No concerns

Ingredients Side-by-side

Water

Niacinamide

Glycerin

Acacia Senegal Gum

Hydrolyzed Rhizobian Gum

Camellia Sinensis Leaf Extract

Chamomilla Recutita Flower Extract

PCA

Sodium PCA

Sh-Oligopeptide-1

Sh-Oligopeptide-2

Sh-Polypeptide-1

Sh-Polypeptide-11

Sh-Polypeptide-9

Sodium Hyaluronate

Acetyl Hexapeptide-8

Arginine

Aspartic Acid

Acetyl Glutamine

Lecithin

Carnitine

Alanine

Glycine

Histidine

Isoleucine

Phenylalanine

Proline

Serine

Threonine

Valine

Caffeine

Ruscus Aculeatus Root Extract

Chenopodium Quinoa Seed Extract

Bacillus

Citrus Reticulata Peel Extract

Codonopsis Lanceolata Extract

Coix Lacryma-Jobi Ma-Yuen Seed Extract

Chrysanthemum Parthenium Extract

Digitaria Ciliaris Flower Extract

Glycyrrhiza Glabra Root Extract

Nelumbo Nucifera Seed Extract

Paeonia Suffruticosa Root Extract

Paeonia Albiflora Flower Extract

Polygonum Odoratum Extract

Sodium Lactate

Polyglutamic Acid

Xanthan Gum

Butylene Glycol

1,2-Hexanediol

Citric Acid

Caprylyl Glycol

Sodium Benzoate

Sodium Levulinate

Potassium Sorbate

Phenoxyethanol

Water, Niacinamide, Glycerin, Acacia Senegal Gum, Hydrolyzed Rhizobian Gum, Camellia Sinensis Leaf Extract, Chamomilla Recutita Flower Extract, PCA, Sodium PCA, Sh-Oligopeptide-1, Sh-Oligopeptide-2, Sh-Polypeptide-1, Sh-Polypeptide-11, Sh-Polypeptide-9, Sodium Hyaluronate, Acetyl Hexapeptide-8, Arginine, Aspartic Acid, Acetyl Glutamine, Lecithin, Carnitine, Alanine, Glycine, Histidine, Isoleucine, Phenylalanine, Proline, Serine, Threonine, Valine, Caffeine, Ruscus Aculeatus Root Extract, Chenopodium Quinoa Seed Extract, Bacillus, Citrus Reticulata Peel Extract, Codonopsis Lanceolata Extract, Coix Lacryma-Jobi Ma-Yuen Seed Extract, Chrysanthemum Parthenium Extract, Digitaria Ciliaris Flower Extract, Glycyrrhiza Glabra Root Extract, Nelumbo Nucifera Seed Extract, Paeonia Suffruticosa Root Extract, Paeonia Albiflora Flower Extract, Polygonum Odoratum Extract, Sodium Lactate, Polyglutamic Acid, Xanthan Gum, Butylene Glycol, 1,2-Hexanediol, Citric Acid, Caprylyl Glycol, Sodium Benzoate, Sodium Levulinate, Potassium Sorbate, Phenoxyethanol

Rosa Centifolia Flower Water

Isopropyl Myristate

Squalane

Mannitol

Natto Gum

Tripeptide-10 Citrulline

Acetyl Octapeptide-3

Palmitoyl Hexapeptide-12

Acetyl Tetrapeptide-11

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

Magnesium Chloride

Polysorbate 20

Dimethyl Isosorbide

Acrylates/C10-30 Alkyl Acrylate Crosspolymer

Leuconostoc/Radish Root Ferment Filtrate

PEG-8 Dimethicone

Disodium Phosphate

Carbomer

Dextran

Tetradecyl Aminobutyroylvalylaminobutyric Urea Trifluoroacetate

Triethanolamine

Sodium Phosphate

Octyldodecanol

Silica

Sodium Propoxyhydroxypropyl Thiosulfate Silica

Sodium Hydroxide

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

Alternatives

Ingredients Explained

These ingredients are found in both products.

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

Acetyl Hexapeptide-8 (also known as Argireline) is a synthetic hexapeptide that is often called a "topical Botox alternative".

It works by mimicking how Botox relaxes muscles; it interferes with the signaling process that tells your facial muscles to contract. This can help soften expression lines like forehead wrinkles or crow's feet over time.

The comparison to Botox does have limits because the molecule is water-loving and relatively large.

Acetyl Hexapeptide-8 has a hard time absorbing deeply enough through the skin's outer barrier to actually reach the muscles.

So whether it truly works the way Botox does at a biological level is still up for debate, but early clinical outcomes are fairly encouraging.

A 12 week human study of a multi-ingredient regimen containing this ingredient saw:

While some studies have observed improvements in wrinkle appearance, it is important to note that more consistent results are seen in multi-ingredient formulations (vs just Acetyl Hexapeptide-8 alone).

Some research studies also used higher concentrations (up to 10%) while this ingredient is usually found in concentrations up to 0.005% in leave-on formulations.

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.

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.

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.

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.

Sodium Lactate is the sodium salt of lactic acid, an AHA. It is a humectant and sometimes used to adjust the pH of a product.

This ingredient is part of our skin's NMF, or natural moisturizing factor. Our NMF is essential for the hydration of our top skin layers and plasticity of skin. NMF also influences our skin's natural acid mantle and pH, which protects our skin from harmful bacteria.

High percentages of Sodium Lactate can have an exfoliating effect.

Fun fact: Sodium Lactate is produced from fermented sugar.

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. 03Acetyl Hexapeptide-8 (also known as Argireline) is a synthetic hexapeptide that is often called a "topical Botox alternative".
  4. 04It works by mimicking how Botox relaxes muscles; it interferes with the signaling process that tells your facial muscles to contract. This can help soften expression lines like forehead wrinkles or crow's feet over time.
  5. 05The comparison to Botox does have limits because the molecule is water-loving and relatively large.
  6. 06Acetyl Hexapeptide-8 has a hard time absorbing deeply enough through the skin's outer barrier to actually reach the muscles.
  7. 07So whether it truly works the way Botox does at a biological level is still up for debate, but early clinical outcomes are fairly encouraging.
  8. 08A 12 week human study of a multi-ingredient regimen containing this ingredient saw:
  9. 09While some studies have observed improvements in wrinkle appearance, it is important to note that more consistent results are seen in multi-ingredient formulations (vs just Acetyl Hexapeptide-8 alone).
  10. 10Some research studies also used higher concentrations (up to 10%) while this ingredient is usually found in concentrations up to 0.005% in leave-on formulations.
  11. 11Butylene Glycol (or BG) is used within cosmetic products for a few different reasons:
  12. 12Overall, Butylene Glycol is a safe and well-rounded ingredient that works well with other ingredients.
  13. 13Though 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.
  14. 14Caprylyl Glycol is a humectant, skin conditioner, emollient, and preservative booster derived from either caprylic acid or synthetically created.
  15. 15Typical use levels vary from 0.3-1% as a preservative booster and go up to 2% to condition skin.
  16. 16Because it is not a free-fatty acid, this ingredient is fungal acne safe (there's nothing for Malassezia to feed on).
  17. 17Carbomer is a synthetic thickening and gelling agent. It's basically the ingredient that gives a lot of serums, gels, creams, and sunscreens their smooth, non-sticky texture.
  18. 18Although legally permitted at very high levels, carbomers are normally used at concentrations below 1%.
  19. 19It also needs to be neutralized to actually thicken, and because it is a large molecule, it doesn't really penetrate the skin barrier.
  20. 20Allergy-wise, the risk is very low. Clinical studies show carbomers have low potential for skin irritation/sensitization even at concentrations up to 100%.
Source · skinsort.com
02

Product index

Related product references

03

Comparison edit

Read side by side