Stable daily Vitamin C. Freshly activated Vitamin C. One clean, performance-led system. No unnecessary fillers. No ingredient compromise. Real Results. Real People. 8 Weeks. Wendy · Advanced THD Vitamin C Serum · 8 weeks · No filters Dale · Advanced THD Vitamin C Serum · Week 6 · No filters Trial Participant · Advanced Vitamin C System · 8 weeks · No filters Trial Results 8-week independent trial What This System Does The Intrinsic Advanced Vitamin C System combines two complementary forms of Vitamin C in one complete skincare protocol — 8% Tetrahexyldecyl Ascorbate (THD) for stable daily antioxidant support, and freshly activated L-Ascorbic Acid for targeted use. Together, they help support collagen, brighter-looking skin, a smoother texture and a more even-looking skin tone, while helping improve the appearance of pigmentation, sun spots and fine lines over time. What Our Trial Participants Said "Brighter and smoother — my skin tone is so much more even and calmer. The redness I'd had for years just settled down."WendyAdvanced Vitamin C System · 8 weeks "Reduced sunspots, skin feels smoother. Very happy — easy to use, and some visible results."DaleAdvanced Vitamin C System · Week 6 (still using at Week 10) "Fine lines have softened — jaw and neck lines have improved."Trial ParticipantAdvanced Vitamin C System · 8 weeks What's Included Advanced THD Vitamin C Serum — 8% stable, oil-soluble Vitamin C in a water-free lipid serum Vitamin C Activation Booster — the lightweight vehicle for freshly activated Vitamin C Vitamin C Activation Powder — 100% L-Ascorbic Acid, kept dry until the moment of use Why This System Is Different Vitamin C comes in different forms, each with different formulation strengths. L-Ascorbic Acid is the most extensively studied form of Vitamin C, but it is less stable once dissolved in water. THD Vitamin C is oil-soluble and highly stable, making it particularly well suited to consistent daily use. The Intrinsic system brings both approaches together. The 8% THD Serum provides stable daily Vitamin C and antioxidant support, while the Activation System keeps L-Ascorbic Acid dry until use so it can be freshly mixed when needed. WHAT YOU MAY NOTICE WITH CONSISTENT USE Brighter, more even-looking skin tone Smoother-looking skin texture Softer appearance of fine lines Improved appearance of pigmentation and sun spots Support for collagen and firmer-looking mature skin Daily antioxidant support against environmental stressors THIS IS FOR YOU IF: You have mature skin and want to support collagen and the appearance of fine lines Pigmentation, sun spots or uneven skin tone are a concern You want brighter, smoother and more even-looking skin You want Vitamin C that remains stable in the bottle You care deeply about the ingredients in your skincare You want a complete Vitamin C skincare system, rather than just another serum WHY TWO FORMS OF VITAMIN C? L-Ascorbic Acid is the most extensively studied form of Vitamin C in skincare — but it is notoriously unstable in water-based formulas. The moment it is mixed with water, it begins to oxidise and lose potency. Many serums are already significantly degraded by the time they reach your skin. Tetrahexyldecyl Ascorbate (THD) is oil-soluble, highly stable and able to penetrate into the skin's lipid layers where it converts to active Vitamin C. It does not oxidise, does not irritate and does not turn orange in the bottle. The Activation Powder addresses the potency question by keeping 100% pure L-Ascorbic Acid completely dry until the moment of application — delivering Vitamin C at full potency, every time. Two forms. One clean system. No compromise.
