Naturium PHA Topical Acid 12% Versus The INKEY List Polyhydroxy Acid (PHA) Toner

Naturium PHA Topical Acid 12% Versus The INKEY List Polyhydroxy Acid (PHA) Toner

This smoothing serum is formulated around Gluconolactone and Mandelic 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

Propanediol

Gluconolactone

Mandelic Acid

Lactobionic Acid

Glycerin

Sodium Hyaluronate Crosspolymer

Vaccinium Vitis-Idaea Fruit Extract

Sodium Hyaluronate

Hydroxyacetophenone

Sodium Hydroxide

1,2-Hexanediol

Caprylyl Glycol

Ammonium Acryloyldimethyltaurate/Carboxyethyl Acrylate Crosspolymer

Phenoxyethanol

Xanthan Gum

Tocopheryl Acetate

Ethylhexylglycerin

Citric Acid

Sodium Benzoate

Tocopherol

Calcium Gluconate

Water, Propanediol, Gluconolactone, Mandelic Acid, Lactobionic Acid, Glycerin, Sodium Hyaluronate Crosspolymer, Vaccinium Vitis-Idaea Fruit Extract, Sodium Hyaluronate, Hydroxyacetophenone, Sodium Hydroxide, 1,2-Hexanediol, Caprylyl Glycol, Ammonium Acryloyldimethyltaurate/Carboxyethyl Acrylate Crosspolymer, Phenoxyethanol, Xanthan Gum, Tocopheryl Acetate, Ethylhexylglycerin, Citric Acid, Sodium Benzoate, Tocopherol, Calcium Gluconate

Gluconolactone 3%

Niacinamide 3%

Pentylene Glycol

Aloe Barbadensis Leaf Juice

Potassium Sorbate

PPG-26-Buteth-26

PEG-40 Hydrogenated Castor Oil

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.

Ethylhexylglycerin is created from glycerin. It is a multitasker ingredient that:

The CIR Expert Panel found minimal skin absorption or sensitization of any kind in a safety assessment. Though this ingredient is considered well-tolerated, a small number of cases of allergic dermatitis have been published since 2002. Just be sure to patch test if you are unsure.

Industry-reported use ranges from 8% in rinse-off products and 2% in leave-on formulations.

Gluconolactone is a PHA. PHAs are a great gentle alternative to traditional AHAs.

When applied, Gluconolactone has the same affect on skin as AHAs such as lactic acid. It helps dissolve the dead skin cells in the top layer of your skin. This improves texture and brightens the skin.

PHAs are more gentle than AHAs due to their larger structure. They do not penetrate as deeply as AHAs and take a longer time to dissolve dead cells. Studies show PHAs do not cause as much irritation.

Gluconolactone has some interesting properties:

In a 2004 study, Gluconolactone was found to prevent UV damage in mouse skin cells and has not been found to increase sun sensitivity. However, we still recommend wearing SPF daily.

This ingredient is is an created by reacting gluconic acid with an alcohol.

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.

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.

Sodium Hydroxide is also known as lye or caustic soda. It is used to adjust the pH of products; many ingredients require a specific pH to be effective.

In small amounts, sodium hydroxide is considered safe to use. However, large amounts may cause chemical burns due to its high alkaline.

Your skin has a natural pH and acid mantle. This acid mantle helps prevent harmful bacteria from breaking through. The acid mantle also helps keep your skin hydrated.

"Alkaline" refers to a high pH level. A low pH level would be considered acidic.

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!

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