Medik8 C-Tetra 30ml

Lipid Vitamin C Radiance SerumL

A proven low-irritation formula, 96% of sensitive skins found C-Tetra to be gentle on their skin.*

Vitamin C minimises the appearance of fine lines and wrinkles over time, while helping to visibly balance and brighten the skin tone.

Tetrahexyldecyl Ascorbate (Vitamin C) & Vitamin E


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Key Benefits

Daily Glow
The silky jojoba oil-infused serum works to effortlessly give skin a boost of radiance, promoting a visible healthy-looking glow in as little as 7 days.*

Antioxidant Power
Vitamin C and E provide daily protection from harmful free radicals generated by sun exposure, which can cause visible signs of premature ageing.

Gentle yet Effective
Tetrahexyldecyl ascorbate is a stabilised, gentle form of vitamin C which makes it perfect for those new to vitamin C, or sensitive skins that don’t want to compromise on results.

Looking for more power?
Check out C-Tetra Luxe, with double the concentration of vitamin C as C-Tetra and additional brightening and nourishing ingredients for supercharged results.
*Proven via independent consumer study conducted over 4 weeks on 52 participants with sensitive skin.

How It Works
Your skin contains natural antioxidants that work to defend against free radicals from the environment. When these environmental free radicals outweigh your skin’s antioxidants, the skin can no longer protect itself. Free radicals latch onto the defenceless skin cells, causing irreparable damage, which ultimately leads to signs of premature skin ageing.

C-Tetra works to protect the skin from free radical damage, featuring vitamin C to boost the natural antioxidant defence levels in the skin. Vitamin C is a key pillar of our CSA Philosophy, due to being one of the most powerful vitamins for preventing the visible signs of premature skin ageing. Vitamin C helps to brighten the appearance of dark spots and uneven skin tone. The result? Visibly radiant, more youthful-looking skin. C-Tetra contains tetrahexyldecyl ascorbate, a form of vitamin C which is a stabilised modification of ascorbic acid (the purest form of vitamin C) that is gentle on the skin yet proven to deliver visible results.

Vitamin C and vitamin E work together synergistically as ‘network antioxidants’, boosting the serum’s overall antioxidant effect to keep skin protected throughout the day.

C-Tetra is based on jojoba seed oil, for lightweight nourishment and an instant glowing appearance. The natural emollient oil slips effortlessly into the skin barrier, delivering the vitamin C benefits with ease.

Perfect Pair
When combined, vitamin C and sun protection give skin the ultimate protection against the sun and environment throughout the day, to minimise visible signs of premature ageing. Shop our recommended day cream Advanced Day Ultimate Protect under our SPF range.

How To Use
After cleansing in the morning, massage 4 drops across the face, neck and décolletage
Leave to absorb before applying sun protection. We recommend Advanced Day Ultimate Protect.
Patch testing prior to use is advised.


Tetrahexyldecyl Ascorbate
A lipid-soluble form of vitamin C that provides exceptional antioxidant protection from harmful free radicals, while improving the visible signs of ageing for a youthful-looking complexion.

Vitamin E
A lipid-soluble antioxidant that is naturally present in the skin. Vitamin E protects the skin from free radicals and is regenerated by vitamin C for optimum power.

The Science Behind
“It is exceptionally difficult to formulate a long-lasting vitamin C serum that will keep its power over time. It is notoriously unstable, sensitive to oxidation and can often turn yellow in colour, which indicates that it has gone off. Medik8’s C-Tetra range utilises an extremely stable form of vitamin C, called tetrahexyldecyl ascorbate. This molecule is altered to make it less reactive to oxidation, meaning that even 6 months down the line you can be sure your vitamin C is still as potent as when you first opened it.”
Daniel Isaacs, Medik8 Director of Research