
Highlights
WHAT IS IT?
Day cream with 3% vitamin C
FEATURES
Silky and nourishing cream, restores skin radiance, improves skin texture, contains stabilized vitamin C and hyaluronic acid
BEST FOR
normal
CHECKS
FRAGRANCE-FREE, NO SYNTHETIC COLORS, PARABEN FREE, ALCOHOL FREE
Who Is It For?
Adults Looking To Improve Skin Radiance And TextureWhat Does It Help With?
Fine Lines Uneven Skin Tone Skin Radiance Skin Texture Skin Barrier ProtectionBudget
Mid-range ($30-$75)How To Use
Which routine should it be used in?
Instructions:
Key Information
What Medik8 Says
Product Description:
Start your morning with a visibly bright, dewy and energized complexion thanks to C-Tetra Day Cream. Harnessing the proven power of Medik8's original C-Tetra serum in a silky and nourishing cream, C-Tetra Day Cream works to restore the look of skin radiance while deeply nourishing to visibly improve skin texture. 3% stabilized antioxidant vitamin C helps to directly tackle the appearance of fine lines and uneven skin tone while hyaluronic acid supports the skin's natural protective barrier for more youthful-looking skin overall.
About the Brand:
Ingredients Overview
Ingredients List
Aqua (Water), Heptyl Undecylenate, Caprylic/Capric Triglyceride, Tetrahexyldecyl Ascorbate, Methylpropanediol, Cetearyl Olivate, Cetearyl Isononanoate, Distarch Phosphate, Tocopheryl Acetate, Sodium Polyacrylate, Sorbitan Olivate, Sodium Hyaluronate, Caprylyl Glycol, Glycerin, Disodium EDTA, Phenylpropanol, Citrus Grandis (Grapefruit) Peel Oil, Citrus Limon (Lemon) Peel Oil, Citrus Aurantium Bergamia (Bergamot) Fruit Oil, Pelargonium Graveolens (Geranium) Flower Oil, Sodium Hydroxide, Limonene, Citronellol, Linalool, Geraniol, Citral
Key Ingredients
tetrahexyldecyl ascorbate (vitamin C), hyaluronic acid
Ingredients Details
Caprylic/capric Triglyceride
Common Name(s): Mct oil,fractionated coconut oil,c8/c10 triglyceride
CAS Number: 73398-61-5
DESCRIPTION
What It Does: Lightweight, stable emollient that solubilizes oil-soluble actives for excellent delivery without greasy feel.
Why It's Used: Universal lightweight emollient base and solubilizer for oil-soluble actives in serums and low-viscosity formulations where mineral oil or petrolatum would be too heavy.
How It Works: Medium-chain length provides ideal balance of spreading coefficient, penetration rate, and barrier-sealing properties. excellent solubilizer for vitamin e, retinoids, and other lipophilic actives.
Typically Found In: Serums,facial oils,sunscreens,anti-aging products,hair products
TECHNICAL DETAILS
Primary Category: Active ingredient – medium-chain triglyceride emollient
Secondary Functions: Active solubilizer,spreading agent
Application Areas:
Facial Skincare
Body Care
Hair Care
Beard Care
Color Cosmetics (Makeup)
Dietary/Oral Supplements
Typical Concentration Range: 1%–50%
SOURCING & ETHICS
Vegan Status: Yes – from coconut/palm kernel oil
Halal Status: Yes
Source Notes: Fractionated by hydrolysis and re-esterification of coconut oil. only c8 and c10 fatty acids retained.
SKIN COMPATIBILITY
Irritancy Rating: 1/5 – very low
Comedogenicity Rating: 1/5 – very low; medium-chain length generally non-comedogenic
Sensitivity Concerns: Non-irritating.
Safe for Sensitive Skin: Yes
SAFETY & COMPATIBILITY
Safety Profile: Excellent safety profile. ewg score: 1.
Works Well With: Humectants,ceramides,actives as carrier
Avoid Combining With: No significant incompatibilities
SCIENTIFIC NOTE
Mct oil's medium-chain length (c8/c10) provides superior oxidative stability vs longer polyunsaturated chains and better skin aesthetics (lighter, less greasy) vs longer chain emollients (c16/c18). excellent solubilizer for retinoic acid, tocopheryl esters, and other lipophilic actives.
Last Verified: Cosing database,cir safety assessment,ewg skin deep
Primary Sources: 2026-03-12
Cetearyl Isononanoate
Common Name(s): Crodamol sts,light conditioning ester,cetearyl branched ester
CAS Number: 91219-76-2
DESCRIPTION
What It Does: Provides light silky emolliency combining isononanoate lightness with cetearyl conditioning.
Why It's Used: Light conditioning ester — uniquely combines the lightness of branched-acid esters with the skin conditioning of fatty alcohol esters in one ingredient, providing both feel attributes simultaneously.
How It Works: Cetearyl alcohol (c16+c18) + isononanoic acid (3,5,5-trimethylhexanoic) ester. light feel: branched acid. conditioning: cetearyl component. non-greasy. cosmos accepted. crodamol sts: commercial reference.
Typically Found In: Light emollient serums,skin care,body lotion
TECHNICAL DETAILS
Primary Category: Functional ingredient – emollient
Secondary Functions: Barrier sealing,softening
Application Areas:
Facial Skincare
Body Care
Hair Care
Beard Care
Color Cosmetics (Makeup)
Dietary/Oral Supplements
Typical Concentration Range: 1%–20%
SOURCING & ETHICS
Vegan Status: Yes
Halal Status: Yes
Source Notes: Plant-derived, synthetic or animal-derived. verify source.
SKIN COMPATIBILITY
Irritancy Rating: 1/5 – very low
Comedogenicity Rating: 1/5 – low; formulation-dependent
Sensitivity Concerns: Non-irritating.
Safe for Sensitive Skin: Yes
SAFETY & COMPATIBILITY
Safety Profile: Excellent safety profile. ewg score: 1.
Works Well With: Humectants,ceramides,actives as carrier
Avoid Combining With: No significant incompatibilities
SCIENTIFIC NOTE
Cetearyl isononanoate's dual feel profile from two molecular components: isononanoate acid branching provides lightness (prevents ordered surface film); cetearyl alcohol provides conditioning (long-chain skin interaction). same ester linkage delivering both properties — emollient design combining complementary components.
Last Verified: Cosing database,crodamol sts technical literature
Primary Sources: 2026-03-12
Cetearyl Olivate
Common Name(s): Nonionic emulsifier,o/w surfactant,emulsion stabiliser
CAS Number: N/a
DESCRIPTION
What It Does: Stabilises o/w emulsions by forming a molecular monolayer at the oil-water interface, provides co-emulsification synergy with other emulsifiers, and contributes to emulsion texture through interfacial film properties.
Why It's Used: Nonionic emulsifiers are preferred for sensitive skin and ph-extreme formulations — no ionic charge means no electrostatic interaction with skin proteins, no ph-dependent function loss, and compatibility with both anionic and cationic co-ingredients.
How It Works: Hlb determines emulsion type: hlb 8–12 for o/w emulsification; hlb 3–6 for w/o. the peg or glycoside head group provides hydrophilicity while the c16–c18 fatty chain provides lipophilicity. at the o/w interface, nonionic emulsifiers form a mixed monolayer reducing interfacial tension from ~35 mn/m (clean oil-water) to 5–10 mn/m, providing thermodynamic stabilisation.
Typically Found In: Creams,lotions,o/w emulsions
TECHNICAL DETAILS
Primary Category: Active ingredient – cosmetic active
Secondary Functions: Skin conditioning
Application Areas:
Facial Skincare
Body Care
Hair Care
Beard Care
Color Cosmetics (Makeup)
Dietary/Oral Supplements
Typical Concentration Range: 1%–10%
SOURCING & ETHICS
Vegan Status: Conditional
Halal Status: Yes
Source Notes: Commercially produced for cosmetic use. verify vegan/halal status with supplier.
SKIN COMPATIBILITY
Irritancy Rating: 1/5 – very low
Comedogenicity Rating: 0/5 – non-comedogenic
Sensitivity Concerns: Well-tolerated by most skin types.
Safe for Sensitive Skin: Yes
SAFETY & COMPATIBILITY
Safety Profile: Good safety profile at recommended concentrations. ewg score: 1–2.
Works Well With: Standard skincare actives
Avoid Combining With: No known significant incompatibilities
SCIENTIFIC NOTE
Mixed emulsifier systems (e.g., glyceryl stearate + peg-100 stearate, or cetearyl glucoside + cetearyl alcohol) provide better emulsion stability than single emulsifiers — synergistic packing of different molecular geometries creates a more cohesive, mechanically robust interfacial film.
Last Verified: Cosing database,nonionic emulsifier hlb system review
Primary Sources: 2026-03-12
Distarch Phosphate
Common Name(s): Distarch phosphate,natural biopolymer,film-former texture absorbent
CAS Number: N/a
DESCRIPTION
What It Does: Distarch phosphate absorbs surface sebum and cosmetic oils through its porous granule structure, provides a silky soft-focus powdery finish on skin from the biopolymer particle's low friction coefficient, forms a breathable protective film on skin and hair, and acts as an excipient carrier or encapsulation matrix for actives in powder formulations.
Why It's Used: Formulators choose distarch phosphate as a biodegradable, renewable alternative to synthetic polymers (ptfe, nylon, polyethylene) in powder cosmetics — providing equivalent or superior absorbency and skin feel without microplastic regulatory concerns under eu regulation 2023/2055. natural starch granules have an intrinsically soft, semi-crystalline structure (mohs hardness ~1) that spreads smoothly on skin without abrasion, making them preferred over silica or talc when maximum gentleness is required. modified versions (cross-linked, esterified) extend the range of performance from pure powder through gel-forming to film-forming applications.
How It Works: Distarch phosphate works through the physical properties of its semicrystalline polysaccharide granule architecture: (1) oil absorption — starch granules are semicrystalline spheres (amylose crystalline domains surrounded by amorphous amylopectin matrix) with a porous surface and internal channels. surface sebum and oil penetrate the granule via capillary action into these channels and are immobilised by van der waals forces with the polysaccharide chains — providing oil-mattifying at the skin surface; (2) soft-focus texture — granule diameter (5–50 μm, depending on source) and smooth spherical morphology provide low-friction glide between skin surface and the applying finger/brush, with the semicrystalline granule structure being soft enough to deform without sharp edges; (3) film formation — when wetted, starch granules gelatinise (crystalline structure melts to amorphous hydrogel) above 60°c during processing, cooling to form a continuous film. modified starches with crosslinks maintain film integrity without complete gelatinisation; (4) biodegradation — amylase enzymes in soil rapidly hydrolyse the α-1,4 and α-1,6 glycosidic bonds, providing complete mineralisation to co₂ and water — zero environmental persistence compared to synthetic polymer particles.
Typically Found In: Powders,dry shampoos,biodegradable cosmetics
TECHNICAL DETAILS
Primary Category: Active ingredient – cosmetic active
Secondary Functions: Skin conditioning
Application Areas:
Facial Skincare
Body Care
Hair Care
Beard Care
Color Cosmetics (Makeup)
Dietary/Oral Supplements
Typical Concentration Range: 0.5%–30%
SOURCING & ETHICS
Vegan Status: Yes
Halal Status: Yes
Source Notes: Commercially produced for cosmetic use. verify vegan/halal status with supplier.
SKIN COMPATIBILITY
Irritancy Rating: 1/5 – very low
Comedogenicity Rating: 0/5 – non-comedogenic
Sensitivity Concerns: Well-tolerated by most skin types.
Safe for Sensitive Skin: Yes
SAFETY & COMPATIBILITY
Safety Profile: Good safety profile at recommended concentrations. ewg score: 1–2.
Works Well With: Standard skincare actives
Avoid Combining With: No known significant incompatibilities
SCIENTIFIC NOTE
Starch granule oil absorption capacity: oil absorption capacity (oac) of biopolymer powders correlates with granule porosity and internal surface area. rice starch (3–8 μm granules, high surface area) oac ~1.0 g oil/g; tapioca starch (15–35 μm, lower surface area) oac ~0.8 g/g; corn starch (10–25 μm) oac ~0.9 g/g. cross-linked modified starches maintain granule integrity under mechanical stress providing higher effective oac in use conditions. silica (oac ~2.5 g/g) outperforms starches on pure absorbency but the skin feel advantage of the softer biopolymer — particularly the non-abrasive, cushioned texture — justifies the lower oac for sensitive skin powders.
Last Verified: Cosing database,starch biopolymer cosmetic application review
Primary Sources: 2026-03-12