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The Complete Vitamin C System

The Complete Vitamin C System

Most Vitamin C serums are already degrading before they reach your skin. We fixed that.

Regular price £49.00 GBP
Regular price £59.00 GBP Sale price £49.00 GBP
Introductory offer Sold out
Free UK shipping on orders over £30 · £4 under
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Stable daily Vitamin C. Freshly activated Vitamin C. One clean, clinical system.

No fillers. No irritants. No 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 forms of Vitamin C into one integrated daily protocol — stable THD Ascorbate for consistent daily protection, and freshly activated L-Ascorbic Acid for periodic potency. The result is brighter, smoother, more even-looking skin without a single ingredient you would want to avoid.


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."
Wendy
Advanced Vitamin C System · 8 weeks

"Reduced sunspots, skin feels smoother. Very happy — easy to use, and some visible results."
Dale
Advanced Vitamin C System · Week 6 (still using at Week 10)

"Fine lines have softened — jaw and neck lines have improved."
Trial Participant
Advanced Vitamin C System · 8 weeks


What's Included

  • Advanced THD Vitamin C Serum — daily stable Vitamin C in a water-free oil base
  • Vitamin C Activation Booster — the lightweight vehicle for fresh activation
  • Vitamin C Activation Powder — 100% L-Ascorbic Acid, kept dry until the moment of use

Why This System Is Different

Most Vitamin C serums ask you to choose between stability and potency. L-Ascorbic Acid is the most researched form but degrades the moment it is mixed with water. Stable alternatives like THD are gentler and longer-lasting but traditionally lack the clinical backing of L-Ascorbic Acid.

The Intrinsic system does not make you choose. The THD Serum gives you stable daily Vitamin C that works with your skin barrier. The Activation System gives you freshly mixed L-Ascorbic Acid — at full potency, every time — when your skin needs more.

Two forms. One clean system. No compromise.


WHAT YOUR SKIN WILL FEEL

  • Brighter and more even-looking skin tone
  • Smoother skin texture from consistent use
  • Softer appearance of fine lines over time
  • Daily antioxidant protection against environmental stressors
  • Confident that your Vitamin C is stable, clean and actually working

THIS IS FOR YOU IF:

  • You want Vitamin C that doesn't oxidise in the bottle
  • You have ingredient-conscious skin and won't compromise on what you apply
  • You want visible results without aggressive formulations
  • You prefer clean, clinical skincare that works progressively over time
  • You want a complete Vitamin C protocol, not just another serum

WHY THD OVER TRADITIONAL 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.

View full details

Product Details

Key Ingredients

Tetrahexyldecyl Ascorbate (THD)

A highly stable, oil-soluble form of Vitamin C that penetrates into the skin's lipid layers and converts to active Vitamin C. Unlike traditional L-Ascorbic Acid, THD does not oxidise in formula, does not cause irritation and remains effective throughout the product's shelf life. Supports collagen production, protects against oxidative damage and improves skin tone and texture with consistent daily use.

Squalane

A lightweight, highly stable emollient that mimics the skin's natural lipids. Supports a comfortable, non-greasy finish and enhances the delivery of active ingredients into the skin.

Tocopherol (Vitamin E)

Antioxidant support that works synergistically with Vitamin C to protect the skin against environmental stressors and oxidative damage.

L-Ascorbic Acid (Activation Powder)

100% pure L-Ascorbic Acid — the most extensively researched form of Vitamin C in skincare. Kept completely dry and separate until the moment of use, ensuring maximum potency at every application.

Propanediol (Activation Booster)

A lightweight, skin-compatible solvent that dissolves the Activation Powder efficiently and supports seamless delivery to the skin.

Why Intrinsic

Most skincare products are formulated with fillers, stabilisers and synthetic ingredients that pad out the formula and dilute results. At Intrinsic Skincare we believe you should never have to choose between clean ingredients and visible results.

Every Intrinsic formula is naturopath-developed and built on a simple principle — only ingredients that genuinely serve your skin make it into the bottle. No fillers. No compromise. No hidden nasties.

This means higher concentrations of active botanicals and clinical ingredients, products that last longer, and results you can actually see and feel.

Clean. Clinical. Uncompromising.

Directions for use

Directions for Use — Daily

  1. Apply Hyaluronic Acid Serum
  2. Apply 1–2 pumps of Advanced THD Vitamin C Serum
  3. Follow with moisturiser and sunscreen

Directions for Use — Booster Days (2–3 mornings per week)

  1. Apply Hyaluronic Acid Serum
  2. Mix 3 pumps of Vitamin C Activation Booster with 1 slightly rounded scoop of Vitamin C Activation Powder until fully dissolved
  3. Apply to face and neck
  4. Wait 30–60 seconds
  5. Apply 1–2 pumps of Advanced THD Vitamin C Serum
  6. Follow with moisturiser and sunscreen

Full Ingredient List

Ingredients — Advanced THD Vitamin C Serum
Coco-Caprylate/Caprate, C13-15 Alkane, Squalane, Tetrahexyldecyl Ascorbate, Tocopherol

Ingredients — Vitamin C Activation Booster
Aqua, Propanediol, Gluconolactone, Sodium Benzoate, Calcium Gluconate

Ingredients — Vitamin C Activation Powder
Ascorbic Acid

Shipping & Delivery

United Kingdom
We ship to all UK mainland addresses via Royal Mail Tracked 48. Orders are processed within 1-2 business days.

Standard tracked delivery: 2-3 business days — £4.00

Free shipping on all orders over £30.

Returns
We want you to love your Intrinsic Skincare products. If you are not completely satisfied please contact us within 14 days of receiving your order.

Contact us at info@intrinsic-sc.com for all shipping and returns queries.