Peptide Skincare & BeautySkin science and ingredient guides

Skin science article

The INKEY List SuperSolutions 10% Azelaic Serum Redness Relief Solution Versus The INKEY List Tranexamic Acid Serum

The INKEY List SuperSolutions 10% Azelaic Serum Redness Relief Solution Versus The INKEY List Tranexamic Acid Serum This calming serum is formulated around Azelaic Acid to calm redness and clear breakouts. This brightening serum is formulated around Ascorbyl G

The INKEY List SuperSolutions 10% Azelaic Serum Redness Relief Solution Versus The INKEY List Tranexamic Acid Serum

This calming serum is formulated around Azelaic Acid to calm redness and clear breakouts.

This brightening serum is formulated around Ascorbyl Glucoside and Tranexamic Acid to fade the look of dark spots and brighten dull-looking skin.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Azelaic Acid

Propanediol

Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer

Phenoxyethanol

Acacia Senegal Gum

Xanthan Gum

Allantoin

Glycerin

Ethylhexylglycerin

Polysorbate 60

Sorbitan Isostearate

Maltodextrin

Sodium Hydroxide

Hydrolyzed Gardenia Florida Extract

Gardenia Florida Fruit Extract

Polylysine

Water, Azelaic Acid, Propanediol, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Phenoxyethanol, Acacia Senegal Gum, Xanthan Gum, Allantoin, Glycerin, Ethylhexylglycerin, Polysorbate 60, Sorbitan Isostearate, Maltodextrin, Sodium Hydroxide, Hydrolyzed Gardenia Florida Extract, Gardenia Florida Fruit Extract, Polylysine

Butylene Glycol

Ascorbyl Glucoside

Tranexamic Acid

Euterpe Oleracea Fruit Extract

1-Methylhydantoin-2-Imide

Sodium Acrylates Copolymer

Carbomer

Cetearyl Olivate

Benzyl Alcohol

Sorbitan Olivate

Lecithin

Squalane

Sodium Gluconate

Dehydroacetic Acid

Lactobacillus Ferment

Water, Butylene Glycol, Glycerin, Ascorbyl Glucoside, Tranexamic Acid, Euterpe Oleracea Fruit Extract, 1-Methylhydantoin-2-Imide, Sodium Acrylates Copolymer, Phenoxyethanol, Carbomer, Sodium Hydroxide, Cetearyl Olivate, Benzyl Alcohol, Sorbitan Olivate, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Lecithin, Squalane, Ethylhexylglycerin, Sodium Gluconate, Polysorbate 60, Dehydroacetic Acid, Lactobacillus Ferment, Sorbitan Isostearate

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.

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.

This is a synthetic polymer. It helps improve the texture of products by adding thickness and gel-like feel.

It is also an emulsifer, meaning it prevents ingredients such as oil and water from separating. It also helps evenly disperse other ingredients.

Phenoxyethanol is one of the most widely used preservatives in skincare (and for good reason!).

It has a large spectrum of antimicrobial activity and especially effective bacteria, yeast, and mold while only having a weak effect on your skin's natural microbiome.

On a cellular level, it disrupts the cell membranes of microbes by poking holes that make the cell leak. This shuts down the chemical reactions the microbe needs to make energy so it can no longer survive.

Another perk of this ingredient is that it stays functional across a wide pH range (3-10).

You'll often see it paired with boosters like Ethylhexylglycerin; one study showed that a 1:9 ratio of Ethylhexylglycerin to Phenoxyethanol damages bacterial membranes as effectively as doubling the Phenoxyethanol concentration on its own.

Typical use concentrations range from 0.3-1% depending on the formula, and this ingredient is capped at 1% int the EU.

Safety-wise, the fear mongering does not hold up to the evidence. The EU's Scientific Committee on Consumer Safety and FDA consider it safe as a preservative at up to 1%, including for children of all ages.

Adverse systemic effects only showed up in animal studies at exposures roughly 200x higher than what people get from cosmetics. And despite its very widespread use, this ingredient is a rare sensitizer and allergic reactions are uncommon.

Polysorbate 60 is used to help stabilize products. It is a surfactant and emulsifier. These properties help keep ingredients together in a product. Surfactants help reduce surface tension between ingredients with different states, such as liquids and solids. Emulsifiers help prevent oils and waters from separating.

Polysorbate 60 is sorbitol-based and created from the ethoxylation of sorbitan. Ethoxylation is a chemical reaction used to add ethylene oxide. Sorbitan is a the dehydrated version of sorbitol, a sugar found in fruits.

In this case, the 60 comes from reacting 60 units of ethylene oxide with sorbitan.

Polysorbates are commonly used in medicine and foods.

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.

Sorbitan Isostearate is an emulsifer. It is created from isostearic acid and sorbitol.

As an emulsifier, it keeps the water and oil ingredients from separating. This keeps formulas stable and smooth.

In a 24 hour occlusive patch test on 56 subjects, 10% sorbitan isostearate was completely non-irritating. Most formulas use less than 10%.

Because it's a fatty acid ester, it may not be fungal acne safe since the Malassezia yeast can utilize it as a nutrient source.

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.

01

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. 03Caprylic/Capric Triglyceride (aka MCT Oil) is a lightweight emollient, solvent, and texture enhancer. It is considered a skin-softener by helping to prevent moisture loss.
  4. 04Though it behaves like an oil, it is not technically one due to its chemical composition. One perk of this ingredient is that it is very stable, resistant to oxidation, and unlikely to go rancid.
  5. 05In practice, that translates to a long shelf life and a consistently elegant skin feel.
  6. 06While there is an assumption Caprylic Triglyceride can clog pores due to it being derived from coconut oil, there is no research supporting this. Just patch test if you have concerns.
  7. 07Fractionated coconut oil and MCT Oil are both listed as Caprylic/Capric Triglyceride according to INCI. This is because INCI names are based on the ingredient’s final chemical composition and not its marketing name or source.
  8. 08This ingredient is treated as the gold standard fungal acne safe oil. Even though it is coconut derived, the problematic lauric acid is stripped out.
  9. 09This leaves just caprylic (C8) and capric (C10) acid. These chain lengths actually trend antifungal; a 2020 study found caprylic acid was enough to disrupt Malassezia furfur cell membrane, with a caprylic acid derivative damaging membrane structures…
  10. 10Ethylhexylglycerin is created from glycerin. It is a multitasker ingredient that:
  11. 11The 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 …
  12. 12Industry-reported use ranges from 8% in rinse-off products and 2% in leave-on formulations.
  13. 13Glycerin (or glycerol) is a compound naturally found in your skin. It's a powerhouse humectant that pulls water into the stratum corneum.
  14. 14Topically, glycerin does several things at once:
  15. 15Your 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.
  16. 16Aquaporin-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.
  17. 17This 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.
  18. 18Just know very high concentrations (>40%) can feel tacky in low humidity.
  19. 19Glycerin is the name for this ingredient in American English. British English uses Glycerol/Glycerine.
  20. 20Phenoxyethanol is one of the most widely used preservatives in skincare (and for good reason!).
Source · skinsort.com
02

Product index

Related product references

Product

The Inkey List Retinol

The Inkey List Retinol The Inkey List Retinol ingredients explained: Water (Aqua/Eau), Glycerin, Butylene Glycol, Propanediol, Dicaprylyl Carbonate, Tocopherol, Hydroxyethyl Acrylate/Sodium…

Source: incidecoder.comView reference →

Product

The Inkey List PHA Body Water Cream

The Inkey List PHA Body Water Cream The Inkey List PHA Body Water Cream ingredients explained: Aqua (Water/Eau), C15-19 Alkane, Gluconolactone, Polyacrylate Crosspolymer-6, Phenoxyethanol, …

Source: incidecoder.comView reference →
03

Comparison edit

Read side by side