C-Tetra Luxe

The ester in its element

Tetrahexyldecyl ascorbate is an oil-soluble vitamin C, and here it lives entirely in oil: a waterless base of squalane and jojoba, the two plant lipids closest to skin’s own, where the ester is at its most stable and needs no preservative system to protect it. It converts to active vitamin C within the skin, sparing the surface any acidity.

The lipid bench

Passion fruit, sunflower, olive, ginseng, sweet almond and apricot kernel oils bring a spectrum of fatty acids with ethyl linoleate, the essential fatty acid skin cannot make, and vitamin E as the antioxidant partner. A biosurfactant ferment keeps the blend spreading as a fine, fast-absorbing film rather than a slick.

Who the format serves

Dry, mature and barrier-worn skin gets vitamin C and its facial-oil step in one; the grapefruit note keeps it from feeling medicinal.

The trade, stated

Ester chemistry trades raw L-ascorbic speed for gentleness and stability, the same trade as C-Tetra Advanced, here with maximum comfort.

Dry, mature and seasonally parched skin wanting daily vitamin C folded into a facial oil; retinoid users needing the most cushioned morning half; and Advanced users who want a winter-weight alternative.

Worth knowing

Contains sweet almond and apricot kernel oils, avoid with a tree-nut allergy, and grapefruit peel oil with four declared fragrance allergens; patch test if citrus- or fragrance-sensitive. Oilier or congestion-prone skin will be happier with C-Tetra Advanced’s lighter format.

Mornings on clean, dry skin: 3–4 drops warmed between fingertips and pressed over face and neck, followed by moisturiser (or nothing, if skin is happy) and SPF.

In deep winter it doubles as the evening facial-oil step on non-retinoid nights.

Use alongside

The richest seat in the vitamin C row: Advanced is the everyday lotion-serum, Luxe the oil for dry skin and cold months, some keep both and swap seasonally, but never wear two C serums at once. Pairs with an evening retinoid as the morning half of the CSA routine, and sits over water-based serums (HA Densimatrix, Hydra-Cool) if layering, since oil goes last before moisturiser.