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Skin science article

The INKEY List Polyhydroxy Acid (PHA) Toner Versus Pixi Beauty Clarity Tonic

The INKEY List Polyhydroxy Acid (PHA) Toner Versus Pixi Beauty Clarity Tonic This smoothing toner is formulated around Gluconolactone and Niacinamide to refine skin texture and brighten dull-looking skin. This smoothing toner is formulated around Aloe Barbaden

The INKEY List Polyhydroxy Acid (PHA) Toner Versus Pixi Beauty Clarity Tonic

This smoothing toner is formulated around Gluconolactone and Niacinamide to refine skin texture and brighten dull-looking skin.

This smoothing toner is formulated around Aloe Barbadensis Leaf Juice and Glycolic Acid to refine skin texture and clear breakouts.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

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

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

Sodium PCA

Betaine

Lactobacillus Ferment Lysate Filtrate

Glycolic Acid

Sodium Hyaluronate

Salicylic Acid

Glycyrrhiza Glabra Root Extract

Salix Alba Bark Extract

Magnesium Ascorbyl Phosphate

Centella Asiatica Extract

Saccharum Officinarum Extract

Leuconostoc/Radish Root Ferment Filtrate

Populus Tremuloides Bark Extract

Lactic Acid

Sodium Citrate

Phenoxyethanol

Water, Aloe Barbadensis Leaf Juice, Propanediol, Glycerin, Sodium PCA, Betaine, Lactobacillus Ferment Lysate Filtrate, Glycolic Acid, Sodium Hyaluronate, Salicylic Acid, Glycyrrhiza Glabra Root Extract, Salix Alba Bark Extract, Magnesium Ascorbyl Phosphate, Centella Asiatica Extract, Saccharum Officinarum Extract, Leuconostoc/Radish Root Ferment Filtrate, Populus Tremuloides Bark Extract, Lactic Acid, Sodium Citrate, Sodium Hydroxide, Ethylhexylglycerin, Citric Acid, Potassium Sorbate, Sodium Benzoate, Phenoxyethanol

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.

Aloe Barbadensis Leaf Juice is the filtered, stabilized liquid pressed from the inner gel of the aloe vera leaf.

In cosmetics, it shows up as either soothing active or a water-replacement base. It is roughly 98-99% water and the last 1-2% is an interesting mix of polysaccharides, amino acids, vitamins, minerals, and enzymes.

The polysaccharides do most of the work: they bind water at the skin surface for a light, non-greasy hydration boost. And one of the polysaccharides, glycomannan, is linked to fibroblast stimulation + collagen synthesis. This is also why aloe has such a long track record in wound and burn healing.

This ingredient is also calming with anti-inflammatory and mild antimicrobial activity, making it a great pick for sensitive, irritated, or post-sun skin.

Realistic expectations matter though; the solid evidence is mostly limited to hydration, soothing, and wound support. Deeper claims about anti-aging or sun protection are not well backed, and science reviews note it does not prevent radiation-induced skin injury.

Because it plays well with almost everything, it's commonly used as a base alongside other actives like niacinamide or vitamin C.

Typical usage concentrations range from 0.5% (where hydration benefits already show up) all the way to 90%+ (where it replaces water as the main base).

The safety for this ingredient is well-establish as well. Overall, this is a great supporting ingredient for those who want a boost in hydration.

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.

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.

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!

Similar Comparisons

The reference edit

Ingredients, questions
& further reading.

Connected source records selected through this article’s public topic index.

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Formula cabinet

Ingredients & structured notes

Ingredient index

Ingredients Explained

  1. 01These ingredients are found in both products.
  2. 02Ingredients higher up in an ingredient list are typically present in a larger amount.
  3. 03Alanine is an amino acid and is already found in the human body. Our skin uses alanine to build collagen, elastin, and keratin.
  4. 04Arginine is a semi-essential amino acid. This just means our bodies can product a bit on its own, but sometimes needs a little boost from food sources.
  5. 05It is a part of your skin's natural moisturizing factor (NMF), or the water-loving molecules in your outermost layer of skin (stratum corneum) that keeps everything hydrated and happy.
  6. 06Here's an interesting thing about Arginine: your skin converts it into urea through the Krebs-Henseleit urea cycle. Urea is one of the most effective humectants your skin naturally produces.
  7. 07A clinical study showed applying 2.5% arginine hydrochloride to atopic dermatitis skin showed significant urea levels in the stratum corneum and improved moisture in just four weeks.
  8. 08Arginine is also a precursor to nitric oxide; nitric oxide improves microcirculation and supports wound healing and collagen synthesis.
  9. 09One study found that an amino acid complex containing Arginine reduced skin irritation, improved hydration, and accelerated skin repair in clinical / in-vivo studies.
  10. 10Arginine itself is an amino acid and not a fatty acid, oil, or ester. On its own, it's not a direct food source for Malassezia, or the yeast that causes fungal acne.
  11. 11Aspartic Acid is an amino acid that our bodies produce naturally. It is an antioxidant.
  12. 12Our body uses Aspartic Acid to help build collagen and elastin. It also plays a role in hydrating skin.
  13. 13Benzyl Alcohol is an aromatic alcohol with several roles: it's a preservative, solvent, and mild fragrance component with a floral scent.
  14. 14This ingredient has been deemed safe for use in cosmetic formulations at concentrations up to 5%, and up to 10% in hair dyes. You'll typically see 0.5-2% in most rinse-off or leave-on products.
  15. 15As a preservative, it works by disrupting the membrane of microbial proteins. This helps keep bacteria and fungi from growing in your products.
  16. 16The sensitization picture is actually quite assuring as well:of nearly 71,000 patients patch tested with benzyl alcohol, only 0.21% showed a positive reaction with most of them being weakly positive.
  17. 17This led researchers to conclude that benzyl alcohol cannot be regarded as a significant contact allergen.
  18. 18It is worth noting this ingredient is classified as one of the EU's regulated fragrance allergens and restricted to 1% in finished products.
  19. 19Labels must also declare it in concentrations above 0.001% in leave-on products and 0.01% in rinse-off products.
  20. 20At concentrations around 5%, localized redness and itching can appear as a direct irritant response and not as a true allergic reaction.
Source · skinsort.com
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Product index

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Comparison edit

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