Medik8 Crystal Retinal - 3 Versus Medik8 C-Tetra Eye
Updated on June 18, 2025
Overview
What they are
These products are both vegan, cruelty-free, and reef safe . They have a total of 2 ingredients in common
Cool Features
They both contain Vitamin C and Vitamin E
Suited For
They're both likely to be good for dry skin, brightening skin, reducing pores, scar healing and better texture
Free From
They both do not contain any harsh alcohols, parabens or sulfates
What's Inside
They both contain common allergens, fragrances and oils
We independently verify ingredients, and our claims are backed by peer-reviewed research. Spot a product that needs an update? Let us know.
Ingredient Info
Medik8 Crystal Retinal 43 ingredients
Medik8 C-Tetra Eye 10 ingredients
What's inside (and what isn't)
What's inside (and what isn't)
At a glance
Click on any of the items below to learn more
Medik8 Crystal Retinal 43 ingredients
Medik8 C-Tetra Eye 10 ingredients
Key Ingredients
Benefits
Concerns
Key Ingredients
Benefits
Concerns
Ingredients Side-by-side
Water
Skin ConditioningCaprylic/Capric Triglyceride
Masking
Glycerin
Humectant
Isododecane
EmollientCetearyl Olivate
Sodium Acrylate/Sodium Acryloyldimethyl Taurate Copolymer
Emulsion StabilisingCetearyl Alcohol
Emollient
PPG-12/Smdi Copolymer
EmollientSorbitan Olivate
Emulsifying
Tocopheryl Acetate
Antioxidant
Cyclodextrin
AbsorbentSqualane
Emollient
Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer
Emulsion StabilisingHydroxyacetophenone
Antioxidant
3-O-Ethyl Ascorbic Acid
Skin Conditioning
Hydroxypropyl Methylcellulose
Emulsion StabilisingSodium Hyaluronate
Humectant
Phenoxyethanol
Preservative
Tetrahexyldecyl Ascorbate
Antioxidant
Daucus Carota Sativa Seed Oil
Emollient
Retinal
Skin Conditioning
Rubus Chamaemorus Seed Oil
Skin Conditioning
Alumina
Abrasive
Isostearic Acid
Cleansing
Lecithin
Emollient
Polyglyceryl-3 Polyricinoleate
Emulsifying
Lonicera Japonica Flower Extract
Skin ConditioningLonicera Caprifolium Flower Extract
Perfuming
Polyhydroxystearic Acid
Emulsifying
Stearic Acid
Cleansing
Sodium Polyaspartate
HumectantPentylene Glycol
Skin ConditioningCitric Acid
Buffering
Polysorbate 60
Emulsifying
Disodium EDTA
Ethylhexylglycerin
Skin ConditioningBHT
Antioxidant
Sorbitan Isostearate
Emulsifying
Vanilla Planifolia Fruit Extract
Skin Conditioning
Dipteryx Odorata Bean Extract
Masking
Coumarin
Perfuming
CI 14700
Cosmetic ColorantCI 77891
Cosmetic ColorantWater, Caprylic/Capric Triglyceride, Glycerin, Isododecane, Cetearyl Olivate, Sodium Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Cetearyl Alcohol, PPG-12/Smdi Copolymer, Sorbitan Olivate, Tocopheryl Acetate, Cyclodextrin, Squalane, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Hydroxyacetophenone, 3-O-Ethyl Ascorbic Acid, Hydroxypropyl Methylcellulose, Sodium Hyaluronate, Phenoxyethanol, Tetrahexyldecyl Ascorbate, Daucus Carota Sativa Seed Oil, Retinal, Rubus Chamaemorus Seed Oil, Alumina, Isostearic Acid, Lecithin, Polyglyceryl-3 Polyricinoleate, Lonicera Japonica Flower Extract, Lonicera Caprifolium Flower Extract, Polyhydroxystearic Acid, Stearic Acid, Sodium Polyaspartate, Pentylene Glycol, Citric Acid, Polysorbate 60, Disodium EDTA, Ethylhexylglycerin, BHT, Sorbitan Isostearate, Vanilla Planifolia Fruit Extract, Dipteryx Odorata Bean Extract, Coumarin, CI 14700, CI 77891
Ingredients Explained
These ingredients are found in both products.
Ingredients higher up in an ingredient list are typically present in a larger amount.
Tetrahexyldecyl Ascorbate (THD) is a stable and oil-soluble form of Vitamin C.
THD is special in that it has the ability to travel deeper into skin than traditional ascorbic acid while maintaining the same skin benefits (double win!).
Because it’s oil-soluble, THD dives deep into your skin’s fatty layers (think ceramides and cholesterol) to fight off the kind of free radicals that mess with your skin barrier. This makes it a great pair with water-based vitamin C (ascorbic acid) that mainly works on the surface.
Even at just 0.1%, THD is already showing great antioxidant activity. When used up to 2%, it helps keep your skin happy and calm, especially when it’s stressed from pollution or sun.
Want to fade dark spots or tackle hyperpigmentation? You’ll want 5% or more. Pairing it with brightening buddies like niacinamide or licorice root gives even better results. One study even used 30% THD with other brighteners and saw real results on stubborn discoloration, even in melasma-prone skin.
A note on THD: It’s has a slightly silky, oily texture and usually shows up colorless or pale yellow (though the exact shade can vary by supplier).
While you can sneak it into water-based formulas, it really shines when paired with silicones or oils, which help your skin soak it up better.
THD is pretty stable, but it’s still vulnerable to degradation like ascorbic acid. Too much light or heat (above 113°F / 45°C) can break it down over time. Go for dark and opaque packaging that keeps it safe and shady!
Read more about other types of Vitamin C:
Learn more about Tetrahexyldecyl AscorbateTocopheryl Acetate is AKA Vitamin E. It is an antioxidant and protects your skin from free radicals. Free radicals damage the skin by breaking down collagen.
One study found using Tocopheryl Acetate with Vitamin C decreased the number of sunburned cells.
Tocopheryl Acetate is commonly found in both skincare and dietary supplements.
Learn more about Tocopheryl AcetateIngredient Ratings
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When to use
Medik8 Crystal Retinal 43 ingredients
Medik8 C-Tetra Eye 10 ingredients
Reviews
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