Sunday Riley C.E.O. 15% Vitamin C Brightening Serum Versus Peter Thomas Roth Potent-C Niacinamide Discoloration Treatment
Updated on May 29, 2025
Overview
Cool Features
They both contain AHA, Vitamin C and Vitamin E
Suited For
They're both likely to be good for fighting acne, anti aging, dry skin, brightening skin, oily skin, reducing pores, scar healing, dark spots and better texture
Free From
They both do not contain any harsh alcohols, parabens or sulfates
We independently verify ingredients, and our claims are backed by peer-reviewed research. Spot a product that needs an update? Let us know.
Ingredient Info
Sunday Riley C.E.O. 15% Vitamin C Brightening Serum 27 ingredients
Peter Thomas Roth Potent-C Niacinamide Discoloration Treatment 42 ingredients
What's inside (and what isn't)
What's inside (and what isn't)
At a glance
Click on any of the items below to learn more
Sunday Riley C.E.O. 15% Vitamin C Brightening Serum 27 ingredients
Peter Thomas Roth Potent-C Niacinamide Discoloration Treatment 42 ingredients
Key Ingredients
Benefits
Concerns
Key Ingredients
Benefits
Concerns
Ingredients Side-by-side
Water
Skin ConditioningTetrahexyldecyl Ascorbate
Antioxidant
Squalane
Emollient
Polyglyceryl-6 Distearate
Emulsifying
PEG-8 Beeswax
Emulsifying
PPG-12/Smdi Copolymer
EmollientGlycine Soja Sterols
Emollient
Sodium Phytate
Tocopherol
Antioxidant
Acetamidoethoxyethanol
Humectant
Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer
Emulsion StabilisingSodium Acrylate/Sodium Acryloyldimethyl Taurate Copolymer
Emulsion StabilisingJojoba Esters
Emollient
Glycolic Acid
Buffering
Caprylyl Glycol
EmollientCetyl Alcohol
Emollient
Polyglyceryl-3 Beeswax
Emulsifying
Chlorphenesin
Antimicrobial
Glycerin
Humectant
Polysorbate 60
Emulsifying
Sorbitan Isostearate
Emulsifying
Saccharide Isomerate
Humectant
Citrus Aurantium Dulcis Peel Oil
Masking
Citrus Tangerina Peel Oil
Masking
Linalool
Perfuming
Limonene
Perfuming
Phenoxyethanol
Preservative
Water, Tetrahexyldecyl Ascorbate, Squalane, Polyglyceryl-6 Distearate, PEG-8 Beeswax, PPG-12/Smdi Copolymer, Glycine Soja Sterols, Sodium Phytate, Tocopherol, Acetamidoethoxyethanol, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Sodium Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Jojoba Esters, Glycolic Acid, Caprylyl Glycol, Cetyl Alcohol, Polyglyceryl-3 Beeswax, Chlorphenesin, Glycerin, Polysorbate 60, Sorbitan Isostearate, Saccharide Isomerate, Citrus Aurantium Dulcis Peel Oil, Citrus Tangerina Peel Oil, Linalool, Limonene, Phenoxyethanol
Water
Skin ConditioningNiacinamide
Smoothing
Dimethyl Isosorbide
SolventIsononyl Isononanoate
EmollientTranexamic Acid
Astringent
Dimethicone
Emollient
Caprylic/Capric Triglyceride
Masking
Alpha-Arbutin
Antioxidant
Cetyl Alcohol
Emollient
Glyceryl Stearate
Emollient
Pentylene Glycol
Skin ConditioningPropanediol
Solvent
C9-12 Alkane
SolventCitric Acid
Buffering
Glyceryl Stearate Se
Emulsifying
Butyrospermum Parkii Butter
Skin Conditioning
Tetrahexyldecyl Ascorbate
Antioxidant
Kojic Acid
Antioxidant
Resveratrol
Antioxidant
Tocopheryl Acetate
Antioxidant
Diethylhexyl Syringylidenemalonate
Skin ProtectingHydrangea Arborescens Root Extract
Skin ConditioningMorus Alba Root Extract
BleachingScutellaria Lateriflora Extract
Skin ConditioningHydrolyzed Vegetable Protein
Skin ConditioningSilica
Abrasive
Sodium Stearoyl Glutamate
CleansingCoco-Caprylate/Caprate
Emollient
Dimethiconol
Emollient
Glycerin
Humectant
Sodium Phytate
Potassium Sorbate
Preservative
Sodium Benzoate
Masking
Caprylyl Glycol
EmollientHexylene Glycol
EmulsifyingPolysorbate 20
Emulsifying
Ceteth-20
CleansingSteareth-20
CleansingPolyacrylate Crosspolymer-6
Emulsion StabilisingPEG-75 Stearate
Titanium Dioxide
Cosmetic Colorant
Phenoxyethanol
Preservative
Water, Niacinamide, Dimethyl Isosorbide, Isononyl Isononanoate, Tranexamic Acid, Dimethicone, Caprylic/Capric Triglyceride, Alpha-Arbutin, Cetyl Alcohol, Glyceryl Stearate, Pentylene Glycol, Propanediol, C9-12 Alkane, Citric Acid, Glyceryl Stearate Se, Butyrospermum Parkii Butter, Tetrahexyldecyl Ascorbate, Kojic Acid, Resveratrol, Tocopheryl Acetate, Diethylhexyl Syringylidenemalonate, Hydrangea Arborescens Root Extract, Morus Alba Root Extract, Scutellaria Lateriflora Extract, Hydrolyzed Vegetable Protein, Silica, Sodium Stearoyl Glutamate, Coco-Caprylate/Caprate, Dimethiconol, Glycerin, Sodium Phytate, Potassium Sorbate, Sodium Benzoate, Caprylyl Glycol, Hexylene Glycol, Polysorbate 20, Ceteth-20, Steareth-20, Polyacrylate Crosspolymer-6, PEG-75 Stearate, Titanium Dioxide, Phenoxyethanol
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 and emollient, meaning it attracts and preserves moisture.
It is a common ingredient in many products, especially those designed to hydrate skin. The primary benefits are retaining moisture, skin softening, and promoting a healthy skin barrier.
Though Caprylyl Glycol is an alcohol derived from fatty acids, it is not the kind that can dry out skin.
This ingredient is also used as a preservative to extend the life of products. It has slight antimicrobial properties.
Learn more about Caprylyl GlycolCetyl Alcohol is a fatty alcohol. Fatty Alcohols are most often used as an emollient or to thicken a product.
Its main roles are:
Though it has "alcohol" in the name, it is not related to denatured alcohol or ethyl alcohol.
The FDA allows products labeled "alcohol-free" to have fatty alcohols.
Learn more about Cetyl AlcoholGlycerin is already naturally found in your skin. It helps moisturize and protect your skin.
A study from 2016 found glycerin to be more effective as a humectant than AHAs and hyaluronic acid.
As a humectant, it helps the skin stay hydrated by pulling moisture to your skin. The low molecular weight of glycerin allows it to pull moisture into the deeper layers of your skin.
Hydrated skin improves your skin barrier; Your skin barrier helps protect against irritants and bacteria.
Glycerin has also been found to have antimicrobial and antiviral properties. Due to these properties, glycerin is often used in wound and burn treatments.
In cosmetics, glycerin is usually derived from plants such as soybean or palm. However, it can also be sourced from animals, such as tallow or animal fat.
This ingredient is organic, colorless, odorless, and non-toxic.
Glycerin is the name for this ingredient in American English. British English uses Glycerol/Glycerine.
Learn more about GlycerinPhenoxyethanol is a preservative that has germicide, antimicrobial, and aromatic properties. Studies show that phenoxyethanol can prevent microbial growth. By itself, it has a scent that is similar to that of a rose.
It's often used in formulations along with Caprylyl Glycol to preserve the shelf life of products.
Sodium Phytate is the synthetic salt form of phytic acid. Phytic acid is an antioxidant and can be found in plant seeds.
Sodium Phytate is a chelating agent. Chelating agents help prevent metals from binding to water. This helps stabilize the ingredients and the product.
Tetrahexyldecyl Ascorbate (THD) is a stable and oil-soluble form of Vitamin C.
THD is special in that it has the ability to travel deeper into skin than traditional ascorbic acid while maintaining the same skin benefits (double win!).
Because it’s oil-soluble, THD dives deep into your skin’s fatty layers (think ceramides and cholesterol) to fight off the kind of free radicals that mess with your skin barrier. This makes it a great pair with water-based vitamin C (ascorbic acid) that mainly works on the surface.
Even at just 0.1%, THD is already showing great antioxidant activity. When used up to 2%, it helps keep your skin happy and calm, especially when it’s stressed from pollution or sun.
Want to fade dark spots or tackle hyperpigmentation? You’ll want 5% or more. Pairing it with brightening buddies like niacinamide or licorice root gives even better results. One study even used 30% THD with other brighteners and saw real results on stubborn discoloration, even in melasma-prone skin.
A note on THD: It’s has a slightly silky, oily texture and usually shows up colorless or pale yellow (though the exact shade can vary by supplier).
While you can sneak it into water-based formulas, it really shines when paired with silicones or oils, which help your skin soak it up better.
THD is pretty stable, but it’s still vulnerable to degradation like ascorbic acid. Too much light or heat (above 113°F / 45°C) can break it down over time. Go for dark and opaque packaging that keeps it safe and shady!
Read more about other types of Vitamin C:
Learn more about Tetrahexyldecyl AscorbateWater. 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. Stay hydrated!
Learn more about WaterIngredient Ratings
Here's what our community thinks of the ingredients in these products.
When to use
Sunday Riley C.E.O. 15% Vitamin C Brightening Serum 27 ingredients
Peter Thomas Roth Potent-C Niacinamide Discoloration Treatment 42 ingredients
Reviews
Here's what our community thinks
Sunday Riley C.E.O. 15% Vitamin C Brightening Serum 27 ingredients
Peter Thomas Roth Potent-C Niacinamide Discoloration Treatment 42 ingredients
Be the first to review Potent-C Niacinamide Discoloration Treatment
Write the first review
