Skin science article
The Ordinary Glycolic Acid 7% Toning Solution Versus The INKEY List Glycolic Acid Exfoliating Scalp Scrub
The Ordinary Glycolic Acid 7% Toning Solution Versus The INKEY List Glycolic Acid Exfoliating Scalp Scrub This smoothing toner is formulated around Glycolic Acid to refine skin texture and brighten dull-looking skin. What's inside Key Ingredients Benefits Conc
The Ordinary Glycolic Acid 7% Toning Solution Versus The INKEY List Glycolic Acid Exfoliating Scalp Scrub
This smoothing toner is formulated around Glycolic Acid to refine skin texture and brighten dull-looking skin.
What's inside
Key Ingredients
Benefits
Concerns
Ingredients Side-by-side
Water
Glycolic Acid
Rosa Damascena Flower Water
Centaurea Cyanus Flower Water
Aloe Barbadensis Leaf Water
Propanediol
Glycerin
Triethanolamine
Aminomethyl Propanol
Panax Ginseng Root Extract
Tasmannia Lanceolata Fruit/Leaf Extract
Aspartic Acid
Alanine
Glycine
Serine
Valine
Isoleucine
Proline
Threonine
Histidine
Phenylalanine
Glutamic Acid
Arginine
PCA
Sodium PCA
Sodium Lactate
Fructose
Glucose
Sucrose
Urea
Hexyl Nicotinate
Dextrin
Citric Acid
Polysorbate 20
Gellan Gum
Trisodium Ethylenediamine Disuccinate
Sodium Chloride
Hexylene Glycol
Potassium Sorbate
Sodium Benzoate
1,2-Hexanediol
Caprylyl Glycol
Water, Glycolic Acid, Rosa Damascena Flower Water, Centaurea Cyanus Flower Water, Aloe Barbadensis Leaf Water, Propanediol, Glycerin, Triethanolamine, Aminomethyl Propanol, Panax Ginseng Root Extract, Tasmannia Lanceolata Fruit/Leaf Extract, Aspartic Acid, Alanine, Glycine, Serine, Valine, Isoleucine, Proline, Threonine, Histidine, Phenylalanine, Glutamic Acid, Arginine, PCA, Sodium PCA, Sodium Lactate, Fructose, Glucose, Sucrose, Urea, Hexyl Nicotinate, Dextrin, Citric Acid, Polysorbate 20, Gellan Gum, Trisodium Ethylenediamine Disuccinate, Sodium Chloride, Hexylene Glycol, Potassium Sorbate, Sodium Benzoate, 1,2-Hexanediol, Caprylyl Glycol
Hydrogenated Castor Oil
PEG-40 Hydrogenated Castor Oil
Betaine
Sodium Hydroxide
Polyquaternium-10
Phenoxyethanol
Benzyl Alcohol
Alpha-Glucan Oligosaccharide
Citronellyl Methylcrotonate
Panthenol
Ethylhexylglycerin
Dehydroacetic Acid
Mannitol
Tetraselmis Suecica Extract
Lactic Acid
Potassium Benzoate
Water, Glycolic Acid, Propanediol, Hydrogenated Castor Oil, PEG-40 Hydrogenated Castor Oil, Betaine, Glycerin, Sodium Hydroxide, Polyquaternium-10, Phenoxyethanol, Benzyl Alcohol, Alpha-Glucan Oligosaccharide, Citronellyl Methylcrotonate, Panthenol, Ethylhexylglycerin, Dehydroacetic Acid, Mannitol, Trisodium Ethylenediamine Disuccinate, Sodium Benzoate, Tetraselmis Suecica Extract, Lactic Acid, Potassium Benzoate
Reviews
Alternatives
Ingredients Explained
These ingredients are found in both products.
Ingredients higher up in an ingredient list are typically present in a larger amount.
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.
Glycolic Acid is arguably the most famous alpha hydroxy acid (AHA) with tons of research backing its benefits.
It is found naturally in sugar cane but the form used in skincare is usually synthetic for purity and stability.
Glycolic acid removes the top layer of dead skin cells to allow newer and fresher ones to emerge.
AHAs work by breaking down the structural “glue” that holds old skin cells in place. When that buildup is gone, your skin can renew itself more efficiently.
Research also shows glycolic acid stimulates collagen production, helping to firm and thicken the skin over time. This is one of its biggest advantages over other AHAs.
Overall, glycolic acid helps with:
Fun fact: Glycolic acid boosts skin hydration by helping it produce molecules that increase hyaluronic acid naturally.
To work best, glycolic acid products should have a pH between 3-4 (that’s where exfoliation is most effective but still gentle on skin).
The pH and concentration of a product are key to its effectiveness:
It is normal to feel a slight stinging sensation when using glycolic acid. This usually fades as your skin adjusts.
Because glycolic acid has the smallest molecular size in the AHA family, it can penetrate deeper, which enhances its effectiveness but also makes it more likely to irritate sensitive skin.
If your skin is very sensitive or prone to rosacea, glycolic acid may be too strong; in that case, try milder options like lactic acid or a PHA instead.
Recent studies suggest glycolic acid might even help protect against UV damage. But don’t skip sunscreen! Freshly exfoliated skin is more sensitive to the sun.
Glycolic acid is a skincare superstar. It smooths, brightens, hydrates, and firms the skin. Unless you’re highly sensitive, it’s well worth adding to your routine.
Read more about some other popular AHA's here:
Propanediol is an all-star ingredient. It softens, hydrates, and smooths the skin.
It’s often used to:
Propanediol is not likely to cause sensitivity and considered safe to use. It is derived from corn or petroleum with a clear color and no scent.
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.
Trisodium Ethylenediamine Disuccinate is used to help stabilize a product.
It is a chelating agent, meaning it helps prevent metal ions from binding to other ingredients. This prevents unwanted reactions in products. Metal ions can come into a product via the water ingredient. They are found in trace amounts and are not known to be harmful.
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!