Peptide Skincare & BeautySkin science and ingredient guides

Skin science article

The INKEY List Retinol Serum Versus Neutrogena Rapid Wrinkle Retinol Regenerating Cream

The INKEY List Retinol Serum Versus Neutrogena Rapid Wrinkle Retinol Regenerating Cream This anti-aging serum is formulated around Retinyl Acetate and Palmitoyl Tetrapeptide-7 to soften the look of wrinkles and refine skin texture. This anti-aging moisturizer

The INKEY List Retinol Serum Versus Neutrogena Rapid Wrinkle Retinol Regenerating Cream

This anti-aging serum is formulated around Retinyl Acetate and Palmitoyl Tetrapeptide-7 to soften the look of wrinkles and refine skin texture.

This anti-aging moisturizer is formulated around Retinol and Ascorbic Acid to soften the look of wrinkles and refine skin texture.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Glycerin

Butylene Glycol

Propanediol

Dicaprylyl Carbonate

Retinyl Acetate

Dimethicone

Phenoxyethanol

Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer

Caprylyl Glycol

Phospholipids

Squalane

Glycine Soja Oil

Carbomer

Polysorbate 60

Tocopheryl Acetate

Glycolipids

Sodium Hydroxide

Sodium Phytate

Sorbitan Isostearate

Glycine Soja Sterols

Tetrahexyldecyl Ascorbate

Leuconostoc/Radish Root Ferment Filtrate

Hyaluronic Acid

Sodium Lactate

Tocopherol

Polysorbate 20

Palmitoyl Tetrapeptide-7

Palmitoyl Tripeptide-1

Water, Glycerin, Butylene Glycol, Propanediol, Dicaprylyl Carbonate, Retinyl Acetate, Dimethicone, Phenoxyethanol, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Caprylyl Glycol, Phospholipids, Squalane, Glycine Soja Oil, Carbomer, Polysorbate 60, Tocopheryl Acetate, Glycolipids, Sodium Hydroxide, Sodium Phytate, Sorbitan Isostearate, Glycine Soja Sterols, Tetrahexyldecyl Ascorbate, Leuconostoc/Radish Root Ferment Filtrate, Hyaluronic Acid, Sodium Lactate, Tocopherol, Polysorbate 20, Palmitoyl Tetrapeptide-7, Palmitoyl Tripeptide-1

Pentaerythrityl Tetraethylhexanoate

PPG-15 Stearyl Ether

Stearyl Alcohol

Cetearyl Alcohol

Glyceryl Behenate

Ceteareth-20

Isohexadecane

Dimethicone Crosspolymer

Cyclopentasiloxane

Cellulose

Sodium Polyacrylate

Sodium Acryloyldimethyltaurate/Vp Crosspolymer

Polyacrylamide

C13-14 Isoparaffin

Chlorphenesin

Hydrolyzed Myrtus Communis Leaf Extract

Retinol

BHT

Sodium Hyaluronate

Disodium EDTA

Laureth-7

Ascorbic Acid

Water, Pentaerythrityl Tetraethylhexanoate, Glycerin, Dimethicone, PPG-15 Stearyl Ether, Stearyl Alcohol, Cetearyl Alcohol, Butylene Glycol, Glyceryl Behenate, Ceteareth-20, Isohexadecane, Dimethicone Crosspolymer, Cyclopentasiloxane, Cellulose, Sodium Polyacrylate, Phenoxyethanol, Caprylyl Glycol, Sodium Acryloyldimethyltaurate/Vp Crosspolymer, Polyacrylamide, C13-14 Isoparaffin, Chlorphenesin, Polysorbate 20, Hydrolyzed Myrtus Communis Leaf Extract, Retinol, BHT, Sodium Hyaluronate, Disodium EDTA, Sodium Hydroxide, Laureth-7, Ascorbic Acid

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.

Butylene Glycol (or BG) is used within cosmetic products for a few different reasons:

Overall, Butylene Glycol is a safe and well-rounded ingredient that works well with other ingredients.

Though this ingredient works well with most skin types, some people with sensitive skin may experience a reaction such as allergic rashes, closed comedones, or itchiness.

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).

Dimethicone is a type of synthetic silicone created from natural materials such as quartz. It is also known as polydimethylsiloxane.

What it does:

Dimethicone comes in different viscosities:

Depending on the viscosity, dimethicone has different properties.

Ingredients lists don't always show which type is used, so we recommend reaching out to the brand if you have questions about the viscosity.

This ingredient is unlikely to cause irritation because it does not get absorbed into skin. However, people with silicone allergies should be careful about using this ingredient.

Note: Dimethicone may contribute to pilling. This is because it is not oil or water soluble, so pilling may occur when layered with products. When mixed with heavy oils in a formula, the outcome is also quite greasy.

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.

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 20 is a gentle, water-soluble emulsifier and mild surfactant. It stops oil and water from separating to keep your formulas blended and stable.

It also acts as a mild penetration enhancer by helping active ingredients absorb slightly better.

The common safety discussion around this ingredient involves a manufacturing byproduct called 1,4-dioxane.

Trace amounts can form during production but the EU's Scientific Committee on Consumer Safety has concluded that levels at/below 10 ppm in finished products are safe (commercial products consistently fall within acceptable margins).

True allergic reactions are uncommon and the CIR Expert Panel has confirmed this ingredient to be safe as used in cosmetics.

Because it is derived from lauric acid, it may not be fungal acne safe.

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.

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. 03Butylene Glycol (or BG) is used within cosmetic products for a few different reasons:
  4. 04Overall, Butylene Glycol is a safe and well-rounded ingredient that works well with other ingredients.
  5. 05Though this ingredient works well with most skin types, some people with sensitive skin may experience a reaction such as allergic rashes, closed comedones, or itchiness.
  6. 06Ceramide NP (formerly known as Ceramide 3) is one of the skin's naturally occurring lipids.
  7. 07Since ceramides are the major lipid components of the skin, they are crucial for maintaining skin barrier and hydration. Ceramide NP most closely mirrors the dominant kind in human skin amongst ceramide subtypes.
  8. 08This ceramide works by slotting into gaps within the stratum corneum's lipid matrix to limit trans-epidermal water loss (TEWL) and shield the skin against external irritants.
  9. 09A study with 312 patients found that using a ceramide-containing routine for 4 weeks reduced the severity of atopic dermatitis by over 61%.
  10. 10Another clinical study in subjects aged 60 and older found that a ceramide body wash and moisturizer improved skin dryness and itchy skin in 15 days.
  11. 11Overall, ceramides are considered non-irritating and safety tests have found little to no observable adverse effects from using this ingredient.
  12. 12Ceramide NP is usually sourced from plants (like soybean or rice bran), or produced synthetically.
  13. 13Ethylhexylglycerin is created from glycerin. It is a multitasker ingredient that:
  14. 14The 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 …
  15. 15Industry-reported use ranges from 8% in rinse-off products and 2% in leave-on formulations.
  16. 16Glycerin (or glycerol) is a compound naturally found in your skin. It's a powerhouse humectant that pulls water into the stratum corneum.
  17. 17Topically, glycerin does several things at once:
  18. 18Your 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.
  19. 19Aquaporin-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.
  20. 20This 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.
Source · skinsort.com
02

Product index

Related product references

Product

The Inkey List Fulvic Acid Cleanser

The Inkey List Fulvic Acid Cleanser The Inkey List Fulvic Acid Cleanser ingredients explained: Aqua (Water), Coco-Glucoside, Glycerin, Butylene Glycol, Xanthan Gum, Phenoxyethanol, Benzyl A…

Source: incidecoder.comView reference →
03

Comparison edit

Read side by side