Skin science article
The Ordinary Glycolic Acid 7% Exfoliating Toner Versus The INKEY List Polyhydroxy Acid (PHA) Toner
The Ordinary Glycolic Acid 7% Exfoliating Toner Versus The INKEY List Polyhydroxy Acid (PHA) Toner This smoothing toner is formulated around Glycolic Acid to refine skin texture and brighten dull-looking skin. This smoothing toner is formulated around Gluconol
The Ordinary Glycolic Acid 7% Exfoliating Toner Versus The INKEY List Polyhydroxy Acid (PHA) Toner
This smoothing toner is formulated around Glycolic Acid to refine skin texture and brighten dull-looking skin.
This smoothing toner is formulated around Gluconolactone and Niacinamide 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
Gluconolactone 3%
Niacinamide 3%
Pentylene Glycol
Aloe Barbadensis Leaf Juice
PPG-26-Buteth-26
PEG-40 Hydrogenated Castor Oil
Ethylhexylglycerin
Sodium Hydroxide
Water, Propanediol, Gluconolactone 3%, Niacinamide 3%, Pentylene Glycol, Glycerin, Aloe Barbadensis Leaf Juice, Potassium Sorbate, Sodium Benzoate, PPG-26-Buteth-26, PEG-40 Hydrogenated Castor Oil, 1,2-Hexanediol, Caprylyl Glycol, Ethylhexylglycerin, Citric Acid, Sodium Hydroxide
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.
1,2-Hexanediol is a synthetic liquid and another multi-functional powerhouse.
It is a:
Humectant, drawing moisture into the skin
Emollient, helping to soften skin
Solvent, dispersing and stabilizing formulas
Preservative booster, enhancing the antimicrobial activity of other preservatives
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).
Citric Acid is an alpha hydroxy acid (AHA) naturally found in citrus fruits like oranges, lemons, and limes.
Like other AHAs, citric acid can exfoliate skin by breaking down the bonds that hold dead skin cells together. This helps reveal smoother and brighter skin underneath.
However, this exfoliating effect only happens at high concentrations (20%) which can be hard to find in cosmetic products.
Due to this, citric acid is usually included in small amounts as a pH adjuster. This helps keep products slightly more acidic and compatible with skin's natural pH.
In skincare formulas, citric acid can:
While it can provide some skin benefits, research shows lactic acid and glycolic acid are generally more effective and less irritating exfoliants.
Most citric acid used in skincare today is made by fermenting sugars (usually from molasses). This synthetic version is identical to the natural citrus form but easier to stabilize and use in formulations.
Rosacea skin has a lower threshold for acids generally, with 62.5% of rosacea subjects in one study reacting to lactic acid in a sting test. This is why we mark citric acid as a potential rosacea trigger.
However, this ingredient shows up as a pH adjuster or chelator at roughly 0.1-1% in many products. These low levels are unlikely to be an issue for rosacea skin and becomes a potential trigger at exfoliating concentrations (20%). Because everybody's skin is unique, we recommend a patch test if you are unsure.
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.
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.
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.
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!