Medik8 C-Tetra Eye™

Medik8 C-Tetra Eye is a stabilised vitamin C eye serum that targets the visible signs of ageing around the delicate eye area. It works to smooth the appearance of fine lines and wrinkles, brighten dark circles and discolouration, and provide antioxidant protection against environmental free radical damage. The lightweight oil-serum formula absorbs rapidly, leaving the eye area looking revitalised and youthful.

Medik8 C-Tetra Eye is widely regarded as one of the best vitamin C eye serums for tackling dark circles. It uses lipid-soluble tetrahexyldecyl ascorbate, a stable form of vitamin C that penetrates the skin's barrier effectively to brighten under-eye discolouration. Combined with vitamin E for enhanced antioxidant power, it delivers visible brightening results while being gentle enough for even the most sensitive eye areas.

After cleansing in the morning, use the spatula-style applicator to sweep a small amount of C-Tetra Eye across the under-eye area and brow bone, avoiding the eyelids. Gently pat and blend into the skin using your ring finger. Follow with your regular facial vitamin C serum, moisturiser, and SPF. For best results, use daily as part of your morning skincare routine.

C-Tetra Eye is specifically formulated for the delicate skin around the eyes, while C-Tetra is designed for the wider facial area. Both use the same stabilised form of vitamin C (tetrahexyldecyl ascorbate), but C-Tetra Eye is tailored to be ultra-gentle for the thinner, more sensitive eye contour. Medik8 recommend using both together — C-Tetra Eye around the eyes and C-Tetra or C-Tetra Luxe across the rest of the face — for complete vitamin C coverage.

Yes, C-Tetra Eye is formulated with a low-irritation form of vitamin C that is gentle enough for all skin types, including sensitive skin. Tetrahexyldecyl ascorbate is one of the most well-tolerated forms of vitamin C available, making it ideal for use around the delicate eye area. If you are new to the product, Medik8 recommend completing a patch test at least 24 hours before first use.

Absolutely. C-Tetra Eye fits perfectly into the Medik8 CSA Philosophy — vitamin C and sunscreen by day, vitamin A by night. In the morning, apply C-Tetra Eye around the eyes first, then follow with your C-Tetra or C-Tetra Luxe facial serum, moisturiser, and SPF. In the evening, switch to your vitamin A treatment such as Crystal Retinal, reserving C-Tetra Eye for morning use only.

Vitamin C is notoriously unstable — it can lose its effectiveness when exposed to light, heat, or air. Medik8 formulate C-Tetra Eye with tetrahexyldecyl ascorbate, an extremely stable form of vitamin C that retains its full potency from the first drop to the last. This means your eye serum is just as effective six months after opening as it was on day one, giving you consistent brightening and anti-ageing results throughout its use.

Yes, C-Tetra Eye is specifically designed to smooth the appearance of fine lines and wrinkles around the eye area. The lipid-soluble vitamin C supports collagen production while providing antioxidant defence against the environmental stressors that contribute to premature ageing. With regular daily use, the eye contour appears visibly firmer, smoother, and more youthful-looking.

Medik8 state that C-Tetra Eye does not contain any ingredients they would recommend avoiding during pregnancy. However, as a cosmetics company, they are unable to provide medical advice relating to pregnancy or breastfeeding. They strongly recommend discussing the full ingredients list with your GP or midwife before introducing any new skincare products during this time.