Peptide Skincare & BeautySkin science and ingredient guides

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The INKEY List Caffeine Eye Cream Versus Simple Skincare Protect 'N' Glow Brightening Eye Gel

The INKEY List Caffeine Eye Cream Versus Simple Skincare Protect 'N' Glow Brightening Eye Gel This anti-aging eye moisturizer is formulated around Caffeine and Palmitoyl Tetrapeptide-7 to soften the look of wrinkles. This brightening eye moisturizer is formula

The INKEY List Caffeine Eye Cream Versus Simple Skincare Protect 'N' Glow Brightening Eye Gel

This anti-aging eye moisturizer is formulated around Caffeine and Palmitoyl Tetrapeptide-7 to soften the look of wrinkles.

This brightening eye moisturizer is formulated around Niacinamide and Sodium Ascorbyl Phosphate to brighten dull-looking skin.

What's inside

Key Ingredients

Benefits

Concerns

No concerns

Ingredients Side-by-side

Water

Glycerin

Dicaprylyl Carbonate

Propanediol

Polyglyceryl-6 Distearate

Cetyl Alcohol

Glyceryl Behenate

Phenoxyethanol

Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer

Jojoba Esters

Albizia Julibrissin Bark Extract

Squalane

Caffeine

Polyglyceryl-3 Beeswax

Phospholipids

Ethylhexylglycerin

Xanthan Gum

Glycine Soja Oil

Polysorbate 60

Sodium Phytate

Glycolipids

Sorbitan Isostearate

Butylene Glycol

Citric Acid

Glycine Soja Sterols

Leuconostoc/Radish Root Ferment Filtrate

Hyaluronic Acid

Sodium Benzoate

Tocopherol

Carbomer

Darutoside

Sodium Lactate

Polysorbate 20

Palmitoyl Tetrapeptide-7

Palmitoyl Tripeptide-1

Water, Glycerin, Dicaprylyl Carbonate, Propanediol, Polyglyceryl-6 Distearate, Cetyl Alcohol, Glyceryl Behenate, Phenoxyethanol, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Jojoba Esters, Albizia Julibrissin Bark Extract, Squalane, Caffeine, Polyglyceryl-3 Beeswax, Phospholipids, Ethylhexylglycerin, Xanthan Gum, Glycine Soja Oil, Polysorbate 60, Sodium Phytate, Glycolipids, Sorbitan Isostearate, Butylene Glycol, Citric Acid, Glycine Soja Sterols, Leuconostoc/Radish Root Ferment Filtrate, Hyaluronic Acid, Sodium Benzoate, Tocopherol, Carbomer, Darutoside, Sodium Lactate, Polysorbate 20, Palmitoyl Tetrapeptide-7, Palmitoyl Tripeptide-1

Niacinamide

Tetrahydroxypropyl Ethylenediamine

Caprylyl Glycol

Saccharide Isomerate

Hydrolyzed Lupine Protein

Disodium EDTA

Medicago Sativa Seed Extract

Tocopheryl Acetate

Sodium Ascorbyl Phosphate

Sodium Citrate

Zingiber Officinale Root Juice

Water, Propanediol, Niacinamide, Glycerin, Tetrahydroxypropyl Ethylenediamine, Caprylyl Glycol, Phenoxyethanol, Carbomer, Saccharide Isomerate, Citric Acid, Hydrolyzed Lupine Protein, Disodium EDTA, Medicago Sativa Seed Extract, Tocopheryl Acetate, Sodium Ascorbyl Phosphate, Sodium Citrate, Ethylhexylglycerin, Zingiber Officinale Root Juice

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.

Carbomer is a synthetic thickening and gelling agent. It's basically the ingredient that gives a lot of serums, gels, creams, and sunscreens their smooth, non-sticky texture.

Although legally permitted at very high levels, carbomers are normally used at concentrations below 1%.

It also needs to be neutralized to actually thicken, and because it is a large molecule, it doesn't really penetrate the skin barrier.

Allergy-wise, the risk is very low. Clinical studies show carbomers have low potential for skin irritation/sensitization even at concentrations up to 100%.

A 2024 UK study patch-tested 1,302 patients and found true allergy to the parent group of carbomer to be rare with no confirmed relevant reactions.

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.

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.

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.

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

The Inkey List Niacinamide SerumIngredients explained

  1. 01Good old water, aka H2O. The most common skincare ingredient of all. You can usually find it right in the very first spot of the ingredient list, meaning it’s the biggest thing out of all the stuff that makes up the product.
  2. 02It’s mainly a solvent for ingredients that do not like to dissolve in oils but rather in water.
  3. 03Expand to read more
  4. 04Once inside the skin, it hydrates, but not from the outside - putting pure water on the skin (hello long baths!) is drying.
  5. 05One more thing: the water used in cosmetics is purified and deionized (it means that almost all of the mineral ions inside it is removed). Like this, the products can stay more stable over time.
  6. 06A multi-functional skincare superstar with several proven benefits for the skin
  7. 07Great anti-aging, wrinkle smoothing ingredient used at 4-5% concentration
  8. 08Fades brown spots alone or in combination with amino sugar, acetyl glucosamine
  9. 09Increases ceramide synthesis that results in a stronger, healthier skin barrier and better skin hydration
  10. 10Can help to improve several skin conditions including acne, rosacea, and atopic dermatitis
  11. 11A natural moisturizer that’s also in our skin
  12. 12A super common, safe, effective and cheap molecule used for more than 50 years
  13. 13Not only a simple moisturizer but knows much more: keeps the skin lipids between our skin cells in a healthy (liquid crystal) state, protects against irritation, helps to restore barrier
  14. 14Effective from as low as 3% with even more benefits for dry skin at higher concentrations up to 20-40%
  15. 15High-glycerin moisturizers are awesome for treating severely dry skin
  16. 16Propanediol is a natural alternative for the often used and often bad-mouthed propylene glycol. It's produced sustainably from corn sugar and it's Ecocert approved.
  17. 17It's quite a multi-tasker: can be used to improve skin moisturization, as a solvent, to boost preservative efficacy or to influence the sensory properties of the end formula.
  18. 18Butylene glycol, or let’s just call it BG, is a multi-tasking colorless, syrupy liquid. It’s a great pick for creating a nice feeling product.
  19. 19BG’s main job is usually to be a solvent for the other ingredients. Other tasks include helping the product to absorb faster and deeper into the skin (penetration enhancer), making the product spread nicely over the skin (slip agent), and attracting…
  20. 20It’s an ingredient whose safety hasn’t been questioned so far by anyone (at least not that we know about). BG is approved by Ecocert and is also used enthusiastically in natural products. BTW, it’s also a food additive.
Source · incidecoder.com
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Product index

Related product references

Product

The Inkey List Multi-Biotic

The Inkey List Multi-Biotic The Inkey List Multi-Biotic ingredients explained: Water (Aqua/Eau), Inulin, Glycerin, Isoamyl Laurate, Propanediol, Squalane, Cetearyl Olivate, Sorbitan Olivate…

Source: incidecoder.comView reference →
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Comparison edit

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