The Medik8 brand was a pioneer in utilizing a fat-soluble, stable form of ascorbic acid—tetrahexyldecyl ascorbate (THD). This form is distinguished by its low irritant potential (making it suitable for sensitive skin) and its effectiveness in addressing uneven skin tone and loss of firmness. Over time, the brand expanded its range of vitamin C products, incorporating other forms of ascorbic acid and enhancing them with unique and potent antioxidants.
Currently, Medik8 uses the following forms of vitamin C in its products: tetrahexyldecyl ascorbate, ethyl ascorbic acid, and L-ascorbic acid. These are all variations of ascorbic acid or ascorbic acid itself, known for effectively targeting pigmentation, improving skin firmness, and minimizing the appearance of wrinkles and enlarged pores by stimulating collagen production. Additionally, vitamin C is an excellent antioxidant, crucial for protecting the skin against photo-damage and, more broadly, against aging.
Vitamin C is an all-season ingredient. It integrates well into skincare routines throughout the year and is most beneficial when applied in the morning (although applying vitamin C products in the evening is neither prohibited nor harmful).
Here’s how C-Tetra and C-Tetra Luxe serums differ and who they are suitable for:
C-Tetra Serum
This is the classic product that started it all. It was the first vitamin C product in the brand’s collection and has remained a bestseller for many years. The formula contains 7% THD—a significant amount, given that this form of vitamin C is effective at concentrations as low as 1%. It’s suitable for sensitive skin and non-irritating. Vitamin C in this product is stabilized with vitamin E, a well-known combination. The serum has an oil base, with a light, liquid oil texture. It is typically comfortable for dehydrated or slightly dry skin, but very oily skin may not find it as agreeable. It’s essential to pair C-Tetra with a moisturizer. We recommend Total Moisture, Balance Moisturiser, or Advanced Night Restore, depending on your skin’s oiliness and hydration levels.
C-Tetra Luxe Serum
This is a more powerful version of C-Tetra, also with an oil base. It contains 14% THD. However, the differences go beyond the concentration of the active ingredient; these products serve slightly different purposes. C-Tetra Luxe’s formula focuses on brightening pigmentation, with enhanced performance in addressing post-acne marks more effectively and quickly. Its additional ingredients include vitamin F, squalane, red ginseng extract, and Sopholiance™. The latter component makes the formula particularly beneficial for oily, acne-prone skin, as it has antimicrobial properties (P. acnes bacteria, which contribute to acne, strongly dislike it).
