Medik8 C-Tetra Luxe Review

Medik8 C-Tetra Luxe is a richer, oil-based vitamin C serum built for dry, dehydrated and sensitive skin. It contains 14% Tetrahexyldecyl Ascorbate — double the concentration found in the original C-Tetra — blended with squalane, vitamin E and antioxidant plant extracts in a velvety, non-greasy base designed to sit comfortably even on reactive complexions.

What is C-Tetra Luxe?

C-Tetra Luxe sits at the top of Medik8's vitamin C range as the richer sibling to the brand's original C-Tetra serum. Both use Tetrahexyldecyl Ascorbate, a lipid-soluble, stabilised form of vitamin C chosen because it tends to be gentler on skin than pure L-ascorbic acid while still delivering antioxidant support. C-Tetra Luxe carries this ingredient at 14% concentration, which Medik8 states is double the level used in the standard C-Tetra formula, and pairs it with Squalane, Maracuja Oil, Vitamin F and Optimised Red Ginseng in a lightweight but nourishing oil-serum base. The product comes in a 30ml bottle and is designed to be applied as part of a daily morning routine, layering under moisturiser, SPF and make-up.

Key ingredients

• Tetrahexyldecyl Ascorbate (14%) — a stable, oil-soluble vitamin C derivative that helps improve the appearance of uneven tone and dullness, and supports the skin's antioxidant defences against everyday environmental stress.
• Squalane — a lightweight emollient that helps reinforce the skin barrier and lock in moisture, which is part of why this formula reads as more comfortable on dry or dehydrated skin than a watery vitamin C serum.
• Maracuja Oil and Vitamin F — plant-derived lipids that contribute to the serum's nourishing, velvety texture and support barrier comfort.
• Optimised Red Ginseng and Vitamin E — included alongside the vitamin C to bolster the formula's overall antioxidant profile.

C-Tetra Luxe vs the original C-Tetra

The core difference is concentration and texture rather than a different active. C-Tetra Luxe uses double the Tetrahexyldecyl Ascorbate of the standard C-Tetra, carried in a richer, oil-forward base with added squalane and plant oils. That makes it the better starting point for dry, dehydrated or sensitive skin, while the original C-Tetra suits those who want a lighter daily vitamin C without the extra richness. Skintique's guide to Medik8's vitamin C serums compares the full range, including where Daily Radiance Vitamin C and Super C Ferulic fit alongside C-Tetra and C-Tetra Luxe.

Who should use it

C-Tetra Luxe is aimed at people with dry, dehydrated or sensitive skin who have found standard vitamin C serums too sharp, tight-feeling or irritating. It also suits anyone layering vitamin C into a cooler-weather or barrier-focused routine, where the extra squalane and plant oils are useful rather than excessive. It is a less obvious fit for oily or acne-prone skin, where a lighter, oil-free vitamin C formula is likely to feel more comfortable and less occlusive.

How to use it

Apply in the morning to cleansed skin, before moisturiser and SPF. As with any vitamin C serum, daily SPF is worth pairing it with, since vitamin C's antioxidant support works alongside — not instead of — sun protection.

Our verdict

C-Tetra Luxe does what its name suggests: it takes the proven Tetrahexyldecyl Ascorbate base of C-Tetra and reworks it into something noticeably richer and more comfortable for skin that struggles with drier, thinner vitamin C serums. If your skin is dry, dehydrated or easily irritated and you have found other vitamin C products too sharp, it is one of the more forgiving options in Medik8's range. If you have oily or combination skin, the standard C-Tetra or a lighter formula such as Daily Radiance Vitamin C is likely to suit better. You can view current pricing and buy C-Tetra Luxe on the Skintique product page.