The INKEY List 1% Retinol Serum Versus ISDIN Isdinceutics Retinal Intense Serum

The INKEY List 1% Retinol Serum Versus ISDIN Isdinceutics Retinal Intense Serum

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

This anti-aging serum is formulated around Retinal and Bakuchiol to soften the look of wrinkles and refine skin texture.

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Glycerin

Prunus Armeniaca Kernel Oil

Persea Gratissima Oil

Caprylic/Capric Triglyceride

Squalane

Cetearyl Alcohol

Glyceryl Stearate Se

Retinol

Phenoxyethanol

Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer

Benzyl Alcohol

Phospholipids

Tocopherol

Polyacrylate Crosspolymer-6

Glycine Soja Oil

Ethylhexylglycerin

Glycolipids

Dehydroacetic Acid

Polysorbate 60

Sorbitan Isostearate

Trisodium Ethylenediamine Disuccinate

Glycine Soja Sterols

T-Butyl Alcohol

Water, Glycerin, Prunus Armeniaca Kernel Oil, Persea Gratissima Oil, Caprylic/Capric Triglyceride, Squalane, Cetearyl Alcohol, Glyceryl Stearate Se, Retinol, Phenoxyethanol, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Benzyl Alcohol, Phospholipids, Tocopherol, Polyacrylate Crosspolymer-6, Glycine Soja Oil, Ethylhexylglycerin, Glycolipids, Dehydroacetic Acid, Polysorbate 60, Sorbitan Isostearate, Trisodium Ethylenediamine Disuccinate, Glycine Soja Sterols, T-Butyl Alcohol

Dimethicone

Dibutyl Adipate

Niacinamide

Isoamyl Laurate

Lauryl PEG/PPG-18/18 Methicone

Propanediol

Dimethicone/Vinyl Dimethicone Crosspolymer

Alcohol Denat.

Bakuchiol

1,2-Hexanediol

Pentylene Glycol

Ethylcellulose

Hydroxyacetophenone

Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate

4-T-Butylcyclohexanol

Caprylyl Glycol

Parfum

Sodium Acrylates Crosspolymer-2

Vigna Aconitifolia Seed Extract

Tocopheryl Acetate

Citric Acid

Xanthan Gum

Maltodextrin

Melatonin

Retinal

Silica

Disodium EDTA

Synthetic Fluorphlogopite

CI 77891

Ascorbic Acid

Rosmarinus Officinalis Leaf Extract

Palmitoyl Tetrapeptide-7

Tin Oxide

Chrysin

Water, Dimethicone, Dibutyl Adipate, Niacinamide, Isoamyl Laurate, Lauryl PEG/PPG-18/18 Methicone, Glycerin, Propanediol, Dimethicone/Vinyl Dimethicone Crosspolymer, Alcohol Denat., Bakuchiol, 1,2-Hexanediol, Pentylene Glycol, Caprylic/Capric Triglyceride, Ethylcellulose, Hydroxyacetophenone, Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate, 4-T-Butylcyclohexanol, Caprylyl Glycol, Parfum, Sodium Acrylates Crosspolymer-2, Polyacrylate Crosspolymer-6, Vigna Aconitifolia Seed Extract, Tocopheryl Acetate, Tocopherol, Citric Acid, Xanthan Gum, Maltodextrin, Melatonin, Retinal, Silica, Disodium EDTA, Phospholipids, Synthetic Fluorphlogopite, CI 77891, Ascorbic Acid, T-Butyl Alcohol, Rosmarinus Officinalis Leaf Extract, Palmitoyl Tetrapeptide-7, Tin Oxide, Chrysin

Alternatives

Ingredients Explained

These ingredients are found in both products.

Ingredients higher up in an ingredient list are typically present in a larger amount.

Caprylic/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.

Though 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.

In practice, that translates to a long shelf life and a consistently elegant skin feel.

While 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.

Fractionated 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.

This ingredient is treated as the gold standard fungal acne safe oil. Even though it is coconut derived, the problematic lauric acid is stripped out.

This 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 at concentrations as low as 0.2%.

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.

Phospholipids are a family of skin-identical lipids that makeup the structural backbone of every cell membrane in your body.

In cosmetics, they function as skin conditioning agents with emulsifier and surfactant properties. They're typically sourced from soybean or sunflower lecithin (or sometimes egg yolk or marine sources).

Because they mirror the lipids naturally found in the deeper layers of your skin, topical phospholipids help reinforce the lipid matrix, reduce transepidermal water loss, and leave skin feeling conditioned.

They're also used to form liposomes, or tiny self-assembling vesible used to stabilize actives like vitamin c or retinol. This helps these ingredients integrate into the upper layers of skin more easily.

Phospholipids are compatible with everything and the CIR Expert Panel has concluded them to be safe at current use levels.

Some types of phospholipids include:

Polyacrylate Crosspolymer-6 is a texture enhancer and pH adjuster.

It is be used to thicken water-based products and create a gel-texture with a velvet feel.

One manufacturer claims this ingredient to have a pH range of 2-8 and to be biodegradable.

This ingredient is also known as Sepimax Zen.

T-Butyl Alcohol (aka tert-butanol) is a small, clear, camphor-smelling alcohol.

It has two main jobs:

On the safety side, it's well-studied and has a solid track record. Human repeat-insult patch testing showed no skin irritation or sensitization even at 100%.

Typical use levels are pretty tiny, usually less than 1%.

You might see some fear-mongering around this ingredient:

Studies in male rats showed kidney effects but that's because of a rat-specific protein that humans don't make. So this study isn't really relevant to humans.

Though it's not a typical fragrance like parfum, it does have a natural scent. That's why the official COSIng database lists it as 'perfuming' ingredient. It can be used to modify the scent of a formula.

Tocopherol is a fat-soluble antioxidant known as Vitamin E.

You'll find this ingredient in the vast majority of skincare (for good reason). It works to neutralize free radicals, or unstable molecules generated by UV exposure, pollution, and other environmental stressors, before they can cause oxidative damage to your skin cells.

Topically applied tocopherol has been shown to protect against UV damage by ramping up the skin's own natural defense enzymes.

It also acts as a skin conditioning agent; some studies show that regular topical use can improve the skin's water-binding capacity over 2-4 weeks.

This ingredient is especially loved for being a team player. When combined with Vitamin C, the photoprotective effect of both ingredients roughly doubles and the combo also helps reduce UV-induced DNA damage.

This ingredient has some brightening potential but it's more of a prevention ingredient than spot-fader. Cell studies show it can slow down melanin production but it's worth noting that it's not the most powerful brightener out there.

In formulations, it also serves as a stabilizer that helps protect other oxidation-prone ingredients from degrading.

Concentrations usually range from 0.1-1% in most leave-on products.

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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