Medik8 C-Tetra Advanced - 30ml

Does your skin look dull and tired, with fine lines, dark circles and enlarged pores becoming more noticeable? Your skin faces environmental stressors every day that accelerate premature ageing. C-Tetra Advanced (the advanced vitamin C serum from Medik8) is made for all skin types looking for powerful antioxidant protection and visible brightening, without disrupting the skin barrier. Clinically proven to brighten skin and visibly improve wrinkles within 7 days.

How it works

The formula combines 20% stabilised vitamin C (tetrahexyldecyl ascorbate, an oil-soluble form that penetrates the skin gently) with innovative phyto exosomes from green tea leaf vesicles and acetyl zingerone, an advanced antioxidant. Together they neutralise the ageing effects of free radicals and support skin recovery after exposure to environmental stressors. Tocopherol (vitamin E) boosts antioxidant performance, while sodium hyaluronate and squalane keep skin supple and hydrated. The serum works smarter, not harsher.

Texture and where it fits in your routine

A lightweight, fast-absorbing serum with a subtle citrus character (grapefruit peel oil). C-Tetra Advanced is the C step in the Medik8 CSA philosophy: vitamin C and sun protection in the morning, vitamin A at night. Apply it in the morning before your moisturiser and always under an SPF such as Advanced Day Ultimate Protect SPF 50+. Want extra hydration? Layer it with Hydr8 B5. In the evening, use Crystal Retinal in the strength that suits your experience level.

Frequently asked questions

Which step of the CSA routine is this?

C-Tetra Advanced is the morning vitamin C step: after cleansing, before moisturiser and SPF. Vitamin C can make skin more sensitive to UV, so daily sun protection is essential.

Can I combine it with retinal?

Yes. Use vitamin C in the morning and Crystal Retinal in the evening. You get daytime protection and overnight renewal without layering the two active steps together.

Is it suitable for sensitive skin?

The formula suits all skin types and does not disrupt the skin barrier. If you are new to vitamin C or your skin reacts easily, build up gradually, for example every other day.

C-Tetra Advanced delivers 20% stabilised vitamin C as tetrahexyldecyl ascorbate, an oil-soluble form that penetrates the skin gently. Combined with phyto exosomes from green tea leaf vesicles and acetyl zingerone, the serum neutralises the ageing effects of free radicals and supports skin recovery after exposure to environmental stressors. Tocopherol strengthens antioxidant performance, while sodium hyaluronate and squalane keep skin supple and comfortable. Clinically proven to brighten skin and visibly improve wrinkles within 7 days, without disrupting the skin barrier.

In the morning, apply a small amount (2 to 3 drops) to cleansed skin before your moisturiser. Allow it to absorb and always finish with a sunscreen, as vitamin C can make skin more sensitive to UV. Use daily for optimal results. If your skin is sensitive to vitamin C, start gradually, for example every other day, and build up.

Clinically proven: brighter skin and visibly improved wrinkles within 7 days. With daily use, the complexion looks more even and radiant, while skin feels supple and better protected against environmental stressors. Fine lines are less noticeable, all without compromising your skin barrier.

• Hyaluronic acid – Can hold up to 1000 times its weight in moisture and provides intensive hydration
• Vitamin C – Stimulates collagen production, protects against free radicals, and brightens the complexion.

Aqua (Water), Tetrahexyldecyl Ascorbate, Isododecane, Propanediol, Acetyl Glucosamine, Squalane, Tocopherol, Acetyl Zingerone, Camellia Sinensis (Green Tea) Leaf Vesicles, Hydroxyacetophenone, Sodium Hyaluronate, Cellulose, Avena Sativa (Oat) Kernel Extract, Glycerin, Hydroxyethyl Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Citrus Grandis (Grapefruit) Peel Oil, Sucrose Stearate, Tetrasodium Glutamate Diacetate, Ethylhexylglycerin, Acrylates/C10-30 Alkyl Acrylate Crosspolymer, Xanthan Gum, Sodium Benzoate, Cellulose Gum, 2-Hexanediol, Polysorbate 60, Sorbitan Isostearate, Citric Acid, Phenoxyethanol, Citral, Linalool, Limonene

The manufacturer is responsible for the composition of the product. As the composition may change, we recommend always checking the ingredients on the packaging.