Sunday Riley A+ High-Dose Retinol Serum Versus Sobel Skin RX 4.5% Retinol Serum
Overview
What they are
These products are both cruelty-free and reef safe . They have a total of 11 ingredients in common
Cool Features
They both contain retinoid
Suited For
They're both likely to be good for fighting acne, anti aging, dry skin, brightening skin, sensitive skin, oily skin, reducing pores, scar healing, dark spots and better texture
Free From
They both do not contain any common allergens, parabens or sulfates
What's Inside
They both contain oils
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 A+ High-Dose Retinol Serum 55 ingredients
Sobel Skin RX 4.5% Retinol Serum 30 ingredients
About this product
About this product
At a glance
Click on any of the items below to learn more
Sunday Riley A+ High-Dose Retinol Serum 55 ingredients
Sobel Skin RX 4.5% Retinol Serum 30 ingredients
Key Ingredients
Benefits
Concerns
Key Ingredients
Benefits
Concerns
Ingredients Side-by-side
Ingredients Explained
These ingredients are found in both products.
Ingredients higher up in an ingredient list are typically present in a larger amount.
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. Stay hydrated!
Learn more about WaterDimethyl Isosorbide is a solvent and helps deliver actives into your skin. It is created from sorbitol.
As a solvent, dimethyl isosorbide helps dissolve other ingredients. This helps ensure even distribution of an ingredient. It may also be used to decrease the thickness of a product.
Studies show dimethyl isosorbide is able to penetrate skin to deliver other ingredients into the skin, making them more effective.
Learn more about Dimethyl IsosorbideGlycerin 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 GlycerinPentylene glycol is typically used within a product to thicken it. It also adds a smooth, soft, and moisturizing feel to the product. It is naturally found in plants such as sugar beets.
The hydrophilic trait of Pentylene Glycol makes it a humectant. As a humectant, Pentylene Glycol helps draw moisture from the air to your skin. This can help keep your skin hydrated.
This property also makes Pentylene Glycol a great texture enhancer. It can also help thicken or stabilize a product.
Pentylene Glycol also acts as a mild preservative and helps to keep a product microbe-free.
Some people may experience mild eye and skin irritation from Pentylene Glycol. We always recommend speaking with a professional about using this ingredient in your routine.
Pentylene Glycol has a low molecular weight and is part of the 1,2-glycol family.
Learn more about Pentylene GlycolThis ingredient is a retinoid. It usually goes by a more common name: "Granactive".
Hydroxypinacolone Retinoate (HPR) belongs to the class of retinoids that also includes retinol and tretinoin.
Retinoids have been proven to:
So what is the difference between all the retinoids? Most retinoids need to go through a conversion line to become effective on skin. The ending product is retinoic acid. Retinoic acid is AKA tretinoin.
HPR is an ester of tretinoin. Emerging studies suggest HPR to have an added benefit that other retinoids don't have: Low irritation.
A study from 2021 found HPR to have the greatest stability when exposed to light and temperature out of all the commercial retinoids.
A note about naming: The name "Granactive" is the trade name and the name most commonly used on packages.
Granactive is the name of the mixture - about 90% solvent and 10% HPR. A product with 5% granactive has 0.5% HPR.
Learn more about Hydroxypinacolone RetinoateRetinol is a gold-standard ingredient for anti-aging. It is a form of Vitamin A and belongs to the class of retinoids that also includes tretinoin.
Why is retinol famous?
It has the most scientific studies backing up its skin benefits out of all the non-prescription ingredients.
Retinol is proven to:
This is why retinol is effective at removing wrinkles, fading dark spots, treating acne, and reducing the appearance of pores.
Studies show retinol is less effective when exposed to UV. Be sure to look for appropriate packaging to keep your retinol potent (similar to Vitamin C).
Using retinol or any retinoids will increase sun-sensitivity in the first few months. Though studies show retinoids increase your skin's natural SPF with continuous use, it is best to always wear sunscreen and sun-protection.
We recommend speaking with a medical professional about using this ingredient during pregnancy.
Retinol may cause irritation in some people, so be sure to patch test. Experts recommend 'ramping up' retinol use: start using this ingredient once a week and work up to using it daily.
Read about Tretinoin
Learn more about RetinolBisabolol is famous for its skin soothing properties. It does this by blocking inflammatory signals, helping to reduce your body's reaction to irritation.
This ingredient also interferes with the process of hyperpigmentation. This can help with reducing dark spots and uneven tone.
Bisabolol is an antioxidant. Antioxidants help fight free-radicals. Free-radicals are molecules that may damage your skin cells. By fighting these free-radicals, Bisabolol may slow down signs of aging.
Studies have shown Bisabolol to have antimicrobial properties and may be a fungicide. These properties help preserve a product's shelf life.
All these properties makes bisabolol a great skin barrier helper ingredient.
Bisabolol also helps the absorption of other ingredients.
Note: Synthetic Bisabolol has been shown to be less effective.
Learn more about BisabololButyrospermum Parkii Butter is a plant lipid from the fruit of the Shea Tree. It is an effective skin hydrator and emollient.
Emollients help soothe and soften your skin. It does this by creating a protective film on your skin. This barrier helps trap moisture and keeps your skin hydrated. Emollients may be effective at treating dry or itchy skin.
Shea butter is rich in antioxidants. Antioxidants help fight free-radicals, or molecules that may harm the body. It is also full of fatty acids including stearic acid and linoleic acid. These acids help replenish the skin and keep skin moisturized.
While Shea Butter has an SPF rating of about 3-4, it is not a sunscreen replacement.
Shea butter may not be fungal acne safe. We recommend speaking with a professional if you have any concerns.
Learn more about Butyrospermum Parkii ButterCaprylyl 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 GlycolHelianthus Annuus Seed Oil is the oil derived from the seeds of a Sunflower. Sunflower seed oil is non-fragrant. It is an emollient, meaning it helps to soften the skin.
Sunflower seed oil contains many fatty acids. The fatty acids found in sunflower seeds include (from highest amount to least): linoleic acid, myristic acid, palmitic acid, stearic acid, arachidic acid, oleic acid, and linolenic acid.
These fatty acids help the skin create ceramides. Ceramides play a role in repairing the skin barrier.
Helianthus Annuus Seed Oil helps moisturize the skin. This in turn helps the skin look more rejuvenated and smoother.
Sunflowers are rich in vitamin E.
Historians believe Indigenous cultures of North America domesticated sunflowers before corn. Thus they relied on sunflower oil for a variety of uses. One such use is moisturizing skin and hair.
Sunflower seed oil may not be fungal acne safe. We recommend speaking with a professional if you have any concerns.
Learn more about Helianthus Annuus Seed OilPhenoxyethanol 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.
Ingredient Ratings
Here's what our community thinks of the ingredients in these products.
When to use
Sunday Riley A+ High-Dose Retinol Serum 55 ingredients
Sobel Skin RX 4.5% Retinol Serum 30 ingredients

Reviews
Here's what our community thinks
Sunday Riley A+ High-Dose Retinol Serum 55 ingredients
Definitely high-dose retinol!
This is a powerful retinol serum that is no joke. I tried easing into it by going every other night, then moved to every night. I ended up with signs of a damaged skin barrier (redness) on my chin. I'm going to lay off this on my chin for a couple weeks, then try again, but stick to every other night. I like that I'm getting a strong dose of an excellent skincare Show more