C-Tetra®

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. | Please Note: Product packaging shown may be different to the product received due to regional variations. 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 sunscreen. We recommend Advanced Day Ultimate Protect . Uses per bottle 200 Guide to Layering Step 1: Cleanse Surface Radiance Cleanse™ Select a Size Full Size (150ml) Full Size (150ml) Travel Size (40ml) Add to Bag £25 Step 2: Tone Press & Clear™ Select a Size Full Size (150ml) Full Size (150ml) (150ml) (30ml) Add to Bag £35 Step 3: Brighten C-Tetra® Select a Size Full Size (30ml) Full Size (30ml) Travel Size (8ml) Add to Bag £45 Step 4: Sunscreen Advanced Day Ultimate Protect™ Full Size (50ml) Add to Bag £59 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. View all No artificial fragrance No synthetic colours 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 Is C-Tetra suitable for sensitive skin? Yes, C-Tetra was designed with gentleness in mind. It has been formulated using a very gentle form of vitamin C called THDA (tetrahexyldecyl ascorbate) that is suitable for all skin types, even if you’re new to vitamin C. C-Tetra has also been tested on an independent consumer panel of sensitive skins, of which 93% agreed it is gentle on their skin. [3] Do I have to use C-Tetra before I can try any of Medik8’s stronger vitamin C serums? No, you do not have to use C-Tetra before trying our other vitamin C products. Our vitamin C products have been created to provide options for different strengths and textures to suit all preferences, so you can choose the one that best fits your needs. If you have sensitive skin and would prefer to try a lower-strength vitamin C, C-Tetra is the right one for you. Does C-Tetra Advanced contain fragrance/essential oils? C-Tetra Advanced contains a natural, uplifting citrus fragrance derived from grapefruit essential oil. Why do you use essential oils/fragrance in your day products - are they safe? To create a beautiful product which we know our customers will want to use every day, we use "low-fragrance" in some products as experience is absolutely key to Medik8. For example, we sometimes use a low level of essential oils to imbue a formula with a subtle and elegant aroma. The fragrances themselves are at low levels and with reduced allergens; at these tiny percentages they are extremely unlikely to irritate the skin. If you have any specific concerns about sensitivities, we always recommend doing a patch test before applying the serum to your face or more sensitive areas. This simple step can help ensure the product is right for you. Help Products About Resources Kelly F. 🇬🇧 Verified Buyer 15/05/26 HA N. 🇺🇸 Verified Buyer 12/05/26 Maiia T. 🇺🇦 Verified Buyer 29/03/26 Catherine M. 🇬🇧 Verified Buyer 27/03/26 Yulia L. 🇺🇸 Verified Buyer 10/03/26 Svetlana Y. 🇩🇪 Verified Buyer 10/01/26 Brighten and protect with Medik8’s C-Tetra, a lightweight vitamin C face serum that boosts radiance, fights free radicals, and supports a youthful glow. 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.