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C-Tetra™

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

Clinically proven to brighten skin and restore visible skin radiance.*

Formulated with 7% tetrahexyldecyl ascorbate, a stabilized, low-irritation form of vitamin C, this lightweight serum targets visibly uneven skin tone and the look of fine lines. Enhanced with soothing centella asiatica to ensure a comfortable application for even the most sensitive skin.

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

 
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C-Tetra™ Day Cream
C-Tetra™ Day Cream
  • Brighten
  • |
  • Smooth
  • |
  • Hydrate
 Lipid 3% Vitamin C Moisturizing Cream
Full Size
Key Benefits
Boost Skin Radiance

89% agree their skin has a visible healthy glow in 7 days**

Brighter, More Even Complexion

Clinically proven to visibly brighten and improve eveness of skin tone*

Gentle On Skin

95% agreed C-Tetra is gentle on their skin**. Rich in soothing properties, it contains centella asiatica to help comfort and support all skin types, including sensitive.

Lightweight Nourishment

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

Proven Results
Before
After
Before
After
4 weeks to visibly brighten skin*
4 weeks to visibly improve evenness of skin tone*
4 weeks to visibly improve skin radiance*
*Proven via independent consumer study conducted over 4 weeks on 52 participants with sensitive skin.
How to Use

First-Time Use

If you're new to C-Tetra we recommend a patch test at least 24 hours before first use. Learn how to patch test here.

Step 1

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

Step 2

Leave to absorb before applying a sunscreen.

Uses per bottle

200
Guide to Layering
Cleanse
Surface Radiance Cleanse
Morning
Evening
Surface Radiance Cleanse
Full Size (5.0 FL. OZ. (150 mL))
Tone
Press & Clear
Morning
Evening
Press & Clear
Select a Size
Brighten
C-Tetra™
Morning
C-Tetra™
(0)
Moisturize
Total Moisture Daily Facial Cream
Morning
Total Moisture Daily Facial Cream
Select a Size
Key Ingredients
7% Stabilized 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 the skin's natural collagen levels for a visibly even, more youthful-looking complexion.

Vitamin E

A powerful antioxidant, vitamin E works to deeply nourish and soften the complexion.

Centella Asiatica

Rich in soothing properties, centella asiatica helps to soothe and support all skin types, especially sensitive skins. .

Centella Asiatica

Rich in soothing properties, centella asiatica helps to soothe and support all skin types, especially sensitive skins. .

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 artificial fragrance
  • No synthetic colors
  • Paraben free
  • Certified by the vegan society
Experts Recommended

Ultra-gentle & perfect for visibly radiant skin

DANIEL ISAACS
Chief Product Officer

I like everything that Medik8 does and this is no exception.

EVE CAMERON
Beauty Director - Red Online

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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 stabilized tetrahexyldecyl ascorbate.
Can I use C-Tetra alongside retinoids?
Absolutely. In fact we recommend the daily use of these 2 powerful actives as our proven pairing for more youthful-looking skin. Apply vitamin C in the morning and vitamin A at night for proven age-defying results.
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 physician or obstetrician before use. As general guidance, this product does not contain any ingredients which we would recommend to avoid during pregnancy, unless advised by your physician.
C-Tetra™