Paula's Choice Resist Triple Active Total Repair Serum Versus Medik8 Crystal Retinal 10

Paula's Choice Resist Triple Active Total Repair Serum Versus Medik8 Crystal Retinal 10

This anti-aging serum is formulated around Niacinamide and Retinyl Propionate to soften the look of wrinkles and fade the look of dark spots.

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

What's inside

Key Ingredients

Benefits

Concerns

Ingredients Side-by-side

Water

Isopropyl Myristate

Caprylic/Capric Triglyceride

Glycerin

Niacinamide

Hydroxystearic Acid

Oryza Sativa Bran Oil

Tocotrienols

Retinyl Propionate

Hexylresorcinol

Acrylates/C10-30 Alkyl Acrylate Crosspolymer

Cetyl Alcohol

Castanea Sativa Leaf Extract

Hydroxyacetophenone

Ceramide AP

1,2-Hexanediol

Caprylyl Glycol

Sodium Hydroxide

Dilauryl Thiodipropionate

Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate

Sodium Phytate

BHT

Water, Isopropyl Myristate, Caprylic/Capric Triglyceride, Glycerin, Niacinamide, Hydroxystearic Acid, Oryza Sativa Bran Oil, Tocotrienols, Retinyl Propionate, Hexylresorcinol, Acrylates/C10-30 Alkyl Acrylate Crosspolymer, Cetyl Alcohol, Castanea Sativa Leaf Extract, Hydroxyacetophenone, Ceramide AP, 1,2-Hexanediol, Caprylyl Glycol, Sodium Hydroxide, Dilauryl Thiodipropionate, Pentaerythrityl Tetra-Di-T-Butyl Hydroxyhydrocinnamate, Sodium Phytate, BHT

Isododecane

Cetearyl Olivate

Sodium Acrylate/Sodium Acryloyldimethyl Taurate Copolymer

Cetearyl Alcohol

PPG-12/Smdi Copolymer

Sorbitan Olivate

Tocopheryl Acetate

Titanium Dioxide

Eclipta Prostrata Extract

Cyclodextrin

Squalane

Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer

Phenoxyethanol

Melia Azadirachta Leaf Extract

Hydroxypropyl Methylcellulose

Sodium Hyaluronate

Tetrahexyldecyl Ascorbate

Rubus Chamaemorus Seed Oil

Alumina

Isostearic Acid

Lecithin

Polyglyceryl-3 Polyricinoleate

Polyhydroxystearic Acid

Stearic Acid

Pentylene Glycol

Retinal

Moringa Oleifera Seed Oil

Sodium Polyaspartate

Climbazole

Disodium EDTA

Lonicera Japonica Flower Extract

Lonicera Caprifolium Flower Extract

Daucus Carota Sativa Seed Oil

Ethylhexylglycerin

3-O-Ethyl Ascorbic Acid

Dipteryx Odorata Bean Extract

Polysorbate 60

Sorbitan Isostearate

Vanilla Planifolia Fruit Extract

Decylene Glycol

Coumarin

Water, Caprylic/Capric Triglyceride, Glycerin, Isododecane, Cetearyl Olivate, Sodium Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Cetearyl Alcohol, PPG-12/Smdi Copolymer, Sorbitan Olivate, Tocopheryl Acetate, Titanium Dioxide, Eclipta Prostrata Extract, Cyclodextrin, Squalane, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Phenoxyethanol, Melia Azadirachta Leaf Extract, Hydroxypropyl Methylcellulose, Sodium Hyaluronate, Tetrahexyldecyl Ascorbate, Rubus Chamaemorus Seed Oil, Alumina, Isostearic Acid, Lecithin, Polyglyceryl-3 Polyricinoleate, Polyhydroxystearic Acid, Stearic Acid, Pentylene Glycol, Retinal, Moringa Oleifera Seed Oil, Sodium Polyaspartate, Climbazole, Disodium EDTA, Lonicera Japonica Flower Extract, Lonicera Caprifolium Flower Extract, Daucus Carota Sativa Seed Oil, Ethylhexylglycerin, 3-O-Ethyl Ascorbic Acid, Dipteryx Odorata Bean Extract, Hydroxyacetophenone, Polysorbate 60, Sorbitan Isostearate, Vanilla Planifolia Fruit Extract, Decylene Glycol, 1,2-Hexanediol, BHT, Coumarin

Reviews

Be the first to review

Alternatives

Ingredients Explained

These ingredients are found in both products.

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

1,2-Hexanediol is a synthetic liquid and another multi-functional powerhouse.

It is a:

Humectant, drawing moisture into the skin

Emollient, helping to soften skin

Solvent, dispersing and stabilizing formulas

Preservative booster, enhancing the antimicrobial activity of other preservatives

BHT is a synthetic antioxidant and preservative.

As an antioxidant, it helps your body fight off free-radicals. Free-radicals are molecules that may damage your skin cells.

As a preservative, it is used to stabilize products and prevent them from degrading. Specifically, BHT prevents degradation from oxidation.

The concerns related to BHT come from oral studies; this ingredient is currently allowed for use by both the FDA and EU.

However, it was recently restricted for use in the UK as of April 2024.

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.

Hydroxyacetophenone is a small phenolic molecule that earns its place in a formulas as an antioxidant and preservative booster.

As a phenol, it is able to neutralize free radicals to protect both the product and the skin from oxidative stress.

Though it can't kill microbes on its own, it works as a good supporting agent when combined with other preservatives like Phenoxyethanol or 1,2-Hexanediol.

This ingredient naturally occurs as piceol in Norwegian spruce needles (~0.4-1.1% dry weight and in cloudberries). Though the cosmetic-grade material is synthesized for purity and consistency.

You'll usually see it used at low levels and suppliers recommend up to 1% added to a water phase.

Safety testing was done at concentrations like 0.05% in SPF products and 0.5% in a Human Repeated Insult Patch Test. The safety evidence is assuring; this ingredient is safe for cosmetics in current use and also holds safety status as a food flavoring as well.

An honest caveat: the "soothing" and "anti-inflammatory" claims come mostly from supplier marketing rather than published clinical trials. The Cosmetic Ingredient Review's own literature search found no useful efficacy studies on this ingredient.

So the antioxidant and preservative-boosting roles are the well supported ones while the calming benefit is plausible but thinly evidenced.

Overall, this is a well-tolerated, low-irritation multitasker that quietly helps a formula stay fresh and stable.

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