A brown bottle labeled "C-Tetra®" by Medik8, with a black dropper, is displayed on a white background alongside clear liquid drops. This vitamin C-rich antioxidant serum enhances skin radiance.
A woman with glowing skin applies Medik8 C-Tetra® vitamin C serum to her cheek, highlighting skincare benefits like radiance, brightness, youthfulness, and nourishment in just seven days.
A woman applies Medik8's C-Tetra® serum against an orange background. Text overlay highlights that 87% of users with sensitive skin find C-Tetra® the gentlest vitamin C serum, enhancing skin radiance.
Medik8's C-Tetra® serum is shown with details on its vitamin C concentration and lightweight texture, designed to enhance skin radiance and reduce fine lines and wrinkles.
Morning skincare graphic: Start with cleansing and toning, followed by Medik8's C-Tetra® for radiant skin, and then apply their sunscreen. Experts suggest using vitamin A at night for anti-aging benefits.
An infographic highlights Medik8's C-Tetra® and four other vitamin C skincare products, each offering unique benefits like enhanced radiance, sensitivity care, and sun protection. Discover how these antioxidant serums meet various skin needs for a glowing, healthy complexion.
Discover radiant skin with Medik8's C-Tetra® skincare set, featuring a Vitamin C serum for brightening, sunscreen for protection, and a Vitamin A cream for renewal. Address 90% of anti-aging needs in just three easy steps.
A brown glass bottle labeled with "C-Tetra®" from Medik8, renowned for its skin radiance-boosting vitamin C formula, comes with a white box featuring matching branding and product details.
A Medik8 C-Tetra® brown dropper bottle, a vitamin C-rich antioxidant serum for skin radiance, stands by its white box on a gray surface against a light background.
A brown bottle labeled "C-Tetra®" by Medik8, with a black dropper, is displayed on a white background alongside clear liquid drops. This vitamin C-rich antioxidant serum enhances skin radiance.
A woman with glowing skin applies Medik8 C-Tetra® vitamin C serum to her cheek, highlighting skincare benefits like radiance, brightness, youthfulness, and nourishment in just seven days.
A woman applies Medik8's C-Tetra® serum against an orange background. Text overlay highlights that 87% of users with sensitive skin find C-Tetra® the gentlest vitamin C serum, enhancing skin radiance.
Medik8's C-Tetra® serum is shown with details on its vitamin C concentration and lightweight texture, designed to enhance skin radiance and reduce fine lines and wrinkles.
Morning skincare graphic: Start with cleansing and toning, followed by Medik8's C-Tetra® for radiant skin, and then apply their sunscreen. Experts suggest using vitamin A at night for anti-aging benefits.
An infographic highlights Medik8's C-Tetra® and four other vitamin C skincare products, each offering unique benefits like enhanced radiance, sensitivity care, and sun protection. Discover how these antioxidant serums meet various skin needs for a glowing, healthy complexion.
Discover radiant skin with Medik8's C-Tetra® skincare set, featuring a Vitamin C serum for brightening, sunscreen for protection, and a Vitamin A cream for renewal. Address 90% of anti-aging needs in just three easy steps.
A brown glass bottle labeled with "C-Tetra®" from Medik8, renowned for its skin radiance-boosting vitamin C formula, comes with a white box featuring matching branding and product details.
A Medik8 C-Tetra® brown dropper bottle, a vitamin C-rich antioxidant serum for skin radiance, stands by its white box on a gray surface against a light background.
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Dullness

C-Tetra®

  • Brighten
  • |
  • Even
  • |
  • Smooth
Lipid 7% Vitamin C Radiance Serum

Restore the look of skin radiance in just 7 days* with cult-favourite C-Tetra.

Formulated with a stabilised form of vitamin C (7%) called tetrahexyldecyl ascorbate (pronounced 'tetra-hexul-deckul as-CORR-bate'), this lightweight serum works to visibly brighten uneven skin tone and reduce the look of fine lines and wrinkles, while remaining gentle on sensitive skin.

Fortified with vitamin E, this antioxidant powerhouse also protects the skin against the ageing and damaging effects of free radicals for a more youthful and healthy-looking complexion overall. The perfect option for those who are new to vitamin C, or those with sensitive skin.

*Proven via independent consumer study conducted over 4 weeks on 52 participants with sensitive skin.
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Reasons to shop Medik8

Free ACS delivery in Cyprus
10% off your first order with newsletter signup
Easy 30 day returns
A white tube of Medik8's Advanced Day Ultimate Protect™ moisturizer SPF 50+, featuring DNA repair enzymes, sits elegantly against a swirled cream backdrop, promising a non-comedogenic finish.
Advanced Day Ultimate Protect™
  • Protect
  • |
  • Repair
  • |
  • Hydrate
 Age-Defying Moisturiser with Photolyase SPF 50+ | PA++++
Full Size (50ml)
Key Benefits
Increased Skin Youthfulness

Proven to simultaneously smooth the look of fine lines and wrinkles while visibly boosting skin glow and radiance.

Lightweight Nourishment

This jojoba (pronounced 'huh-hoh-ba') seed oil-based formula delivers effective yet non-greasy nourishment for visibly softer and comforted skin.

Brighter, More Even Complexion

Proven to visibly brighten the skin tone, for a more even and healthy-looking skin appearance.

Proven Results
7 days to restored skin radiance*
7 days to visibly brighter, smoother skin*
96% of sensitive skins agreed C-Tetra was gentle on the skin*
4 weeks to visibly reduced wrinkles & dark spots*
90% agree skin feels instantly softer*
*Proven via independent consumer study conducted over 4 weeks on 52 participants with sensitive skin.
How to Use

STEP 1

After cleansing in the morning, massage 4 drops across the face, neck and décolletage.

STEP 2

Leave to absorb before applying sunscreen. We recommend Advanced Day Ultimate Protect.

Guide to Layering
Step 1: Cleanse
Medik8
Morning
Evening
Surface Radiance Cleanse™
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Step 2: Tone
Clear bottle of Medik8
Morning
Evening
Press & Clear™
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Step 3: Brighten
A brown bottle labeled "C-Tetra®" by Medik8, with a black dropper, is displayed on a white background alongside clear liquid drops. This vitamin C-rich antioxidant serum enhances skin radiance.
Morning
C-Tetra®
Select a Size
Step 4: Sunscreen
A white tube of Medik8
Morning
Advanced Day Ultimate Protect™
Full Size (50ml)
Key Ingredients
7% Stabilised Vitamin C (tetrahexyldecyl ascorbate)

A low-irritation form of vitamin C that delivers exceptional antioxidant protection against harmful free radical damage while brightening and supporting collagen production for a visibly even, more youthful-looking complexion.

Vitamin E

A powerful antioxidant that provides additional antioxidant protection against the ageing effects of free radicals. It also helps to boost the power of vitamin C for optimum visible results.

Full List of Ingredients
C-Tetra®
Lipid 7% Vitamin C Radiance Serum

Simmondsia Chinensis (Jojoba) Seed Oil, Cyclopentasiloxane, Cyclohexasiloxane, Tetrahexyldecyl Ascorbate, Citrus Grandis (Grapefruit) Peel Oil, Tocopheryl Acetate, PPG-12/SMDI Copolymer, Limonene, Citral, Linalool, Geraniol.

*Although we try our best to ensure this list of ingredients is accurate there may be product upgrades from time to time, or slight variants between different regions based on local laws, meaning the only definitive ingredient list is that which is printed on the product packaging.
  • No synthetic colours
  • Certified by the vegan society
Experts Recommended

Softens visible ageing concerns while being tolerable for all.

BRIDGET MARCH
Digital Beauty Director - Harper's Bazaar

My wrinkles have almost disappeared!

TATIANA S
Verified Medik8 Customer

The Vitamin C Serum Range

A brown bottle labeled "C-Tetra®" by Medik8, with a black dropper, is displayed on a white background alongside clear liquid drops. This vitamin C-rich antioxidant serum enhances skin radiance.
Morning
C-Tetra®
Full Size (30ml) | €56
Strength

7% Stabilised Vitamin C

Texture

Lightweight oil

Skin Types

New to Vitamin C, Sensitive skin

Benefits
  • Brightens
  • Ultra gentle
Key Ingredients
  • 7% Tetrahexyldecyl Ascorbate
  • Vitamin E
A brown bottle of Medik8 C-Tetra® Luxe serum with a dropper, liquid drops, an award badge, and "Dermatologist Recommended" text on a white background—formulated with vitamin C to enhance radiance and target fine lines.
Morning
C-Tetra® Luxe
Full Size (30ml) | €82
Strength

14% Stabilised Vitamin C

Texture

Rich oil

Skin Types

All skin types, First signs of ageing

Benefits
  • Brightens
  • Nourishes
  • Softens Look Of Wrinkles
Key Ingredients
  • 14% Tetrahexyldecyl Ascorbate
  • Squalane
  • Maracuja Oil
A bottle of Medik8 Cyprus C-Tetra® Advanced vitamin C serum with pump, product drops, an award badge, and a "0% Barrier Disruption" badge on a white background for skin brightening and anti-ageing.
Morning
C-Tetra® Advanced
| €89
Strength

20% Stabilised Vitamin C

Texture

Lightweight Gel-Serum

Skin Types

All skin types, Visible signs of ageing

Benefits
  • Brightens
  • Defends Against Premature Skin Ageing
  • Smooths Skin Texture
  • Visibly Improves Wrinkles
  • Advanced Pollution Protection
  • 0% Barrier Disruption
Key Ingredients
  • Phyto Exosomes
  • 20% Tetrahexyldecyl Ascorbate
  • Acetyl Zingerone
A brown bottle labeled "Medik8 Super C Ferulic™" with a dropper cap, lies on a white surface amidst spilled liquid. Text reads: "Dermatologist Recommended." Ideal for protecting against sun-induced aging and achieving skin-brightening results with its vitamin C serum.
Morning
Super C Ferulic™
Full Size (30ml) | €85
Strength

30% Stabilised Vitamin C

Texture

Rich, oil like serum

Skin Types

Advanced signs of sun induced ageing

Benefits
  • Brightens
  • Intense Dark Spot Reduction
  • Visibly Reduces Wrinkles
Key Ingredients
  • 30% Ethylated L-Ascorbic Acid
  • Ferulic Acid
  • Vitamin E
  • Turmeric Root Extract

Complete Your Regime

Reviews

Frequently Asked Questions

What's the difference between C-Tetra and C-Tetra Luxe?
C-Tetra is our original, best-selling vitamin C serum. It's the perfect option for those who are new to vitamin C or those with sensitive skin, who still want visible age-defying results. C-Tetra Luxe is our supercharged vitamin C serum - ideal for those looking for clinical brightening and nourishing power. Both serums are formulated with stabilised tetrahexyldecyl ascorbate.
Can I use C-Tetra alongside vitamin A?
Absolutely. In fact we recommend it as part of our pioneering CSA Philosophy which champions vitamin C plus sunscreen by day, vitamin A by night as the simple secret to glowing, youthful-looking skin.
Can I use C-Tetra if I'm pregnant or breastfeeding?
As a cosmetics company, we are unable to provide product advice in relation to medical conditions such as pregnancy. We would recommend discussing the ingredients with your GP or midwife before use. As general guidance, this product does not contain any ingredients which we would recommend to avoid during pregnancy, unless advised by your doctor.
C-Tetra®
Full Size (30ml)
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