The Skin Diary Pro Helix C Collagen Peptide Brightening Serum 30ml

The Skin Diary's first vitamin C. Moving beyond prevention into advanced skin science.

From the dermatologists behind Night Repair Therapy comes The Skin Diary's first ever vitamin C serum, built on 15% THDA vitamin C.

THDA (tetrahexyldecyl ascorbate) is a stable, oil soluble form of vitamin C that brightens without the sting often linked to traditional vitamin C. For decades, vitamin C has played a defensive role, protecting skin from environmental stressors and helping with dullness. Pro Helix C goes further.

Its patent pending complex combines 15% THDA vitamin C, 0.5% acetyl zingerone and 4.5% collagen signalling peptides, designed to target the pathways behind visible ageing: oxidative stress, collagen decline and the breakdown of the skin's support structure. It is formulated at a neutral pH, gentle enough for sensitive skin.

Key Benefits

• Visible radiance: 94% showed clinically proven brighter skin within 7 days¹
• Smoother looking skin: 84% showed a clinically proven visible reduction in fine lines and wrinkles at 8 weeks²
• Backed by independent science: a statistically significant increase in fibrillin, the scaffold for the skin's elastic fibres, in a University of Manchester skin biopsy study⁴
• Gentle on sensitive skin: dermatologically tested and approved, pH neutral formula
• 73% said they would switch from their current vitamin C product³

Key Ingredients

• 15% THDA vitamin C (tetrahexyldecyl ascorbate): a stable, oil soluble form of vitamin C for powerful brightening without irritation.
• 0.5% acetyl zingerone: a broad acting antioxidant that helps optimise vitamin C and helps defend against collagen breakdown.
• 4.5% collagen signalling peptides: a dual peptide complex that supports collagen and extracellular matrix synthesis, the network that keeps skin firm and supple.

How to Use

Every morning, apply 1 to 2 pumps to clean, dry skin. Massage gently over the face and neck. Follow with a moisturiser and a broad spectrum SPF. Vitamin C supports the skin's antioxidant defences but does not replace daily sun protection.

Complete Your Morning Routine

• Step 1: The Skin Diary Pro Helix C, to brighten and support firmness
• Step 2: EltaMD AM Restore, a lightweight, fragrance free moisturiser with hyaluronic acid
• Step 3: EltaMD UV Clear SPF 46, a calming mineral based sunscreen with niacinamide, suited to sensitive skin. For a sheer tint and extra antioxidant protection, choose EltaMD UV AOX Elements SPF 50.

Night & Day

Pair Pro Helix C in the morning with The Skin Diary Night Repair Therapy at night, for a complete routine from the same dermatologist team.

Suitable For

All skin types, including sensitive skin and anyone who has found vitamin C irritating before. No added fragrance. Clinically proven non comedogenic. Ideal for dullness, uneven tone, fine lines and loss of firmness.

¹ Independent instrumental clinical study, ADSL Ref. 41051, 32 participants, 28 days.
² Independent instrumental clinical study, ADSL Ref. 41053, 32 participants, 56 days.
³ Consumer perception study, ADSL Ref. 41054, 45 participants, 4 weeks.
⁴ University of Manchester, Manchester Patch Test Assay, in vivo skin biopsy study, double blind, vehicle controlled. Data on file, The Skin Diary.