Pro-Helix C
Collagen Peptide Brightening Serum

We have evidence of a measurable structural change within human skin, and that's where the story becomes quite different from a conventional vitamin C serum.
Dr. Clare Kiely
CONSULTANT DERMATOLOGIST
More Than Vitamin C.
15% THDA Vitamin C
The lipid-soluble form. Highly stable, well tolerated, and it penetrates properly rather than sitting on the skin's surface.
4.5% Collagen-Signalling Peptides
Two complementary signals telling your skin to build new collagen - not just protect the old.
0.5% Acetyl Zingerone
The bodyguard. Most antioxidants are depleted the moment they neutralise a free radical. This one keeps going; protecting your collagen for hours after you apply it.
View the full INCI
Aqua, Tetrahexyldecyl Ascorbate, Glycerin, Dipropylene Glycol, Simmondsia Chinensis (Jojoba) Seed Oil, Dicaprylyl Ether, Maltodextrin, Glycine Soja (Soybean) Seed Extract, Acetyl Zingerone, Palmitoyl Tripeptide-5, Collagen Amino Acids, Squalane, Tocopheryl Acetate, Sodium Hyaluronate, Lecithin, Ethylhexylglycerin[1], Sorbitan Isostearate, Hydroxyethyl Acrylate/Sodium, Acryloyldimethyl Taurate Copolymer, Sodium Acrylates Copolymer, Polysorbate 60, Phenoxyethanol, Citric Acid
Why Switch From Your Current Vitamin C Serum?
Pro-Helix C goes beyond glow alone.
Improves Brightness L-Ascorbic (Gold Standard): YesPro-Helix C: Yes
94% of Pro-Helix C clinical trial participants showed brighter skin within 7 days.
Protects Collagen L-Ascorbic (Gold Standard): YesPro-Helix C: Yes
Vitamin C contributes to normal collagen formation for the normal function of the skin.
Provides Antioxidant Protection L-Ascorbic (Gold Standard): YesPro-Helix C: Yes
Vitamin C is the most plentiful antioxidant in human skin. It protects against environmental stressors by donating electrons to neutralise free radicals. Pro-Helix C takes this further showing a 2.4x boost in key antioxidant defence signals created by the body.
Increases Elastic Fibres for Visibly Firmer Skin L-Ascorbic (Gold Standard): NoPro-Helix C: Yes
In a human skin biopsy study, Pro-Helix C showed a significant increase in elastic fibres, namely fibrillin.
Formulated for Sensitive Skin L-Ascorbic (Gold Standard): NoPro-Helix C: Yes
Pro-Helix C uses a combination of THDA vitamin C and acetyl-zingerone to create a lipid-soluble form of vitamin C that is stable. This means we have been able to formulate the product at a neutral pH with no added fragrance, which doesn't cause irritation to sensitive skin and doesn’t block pores.
Powered by Collagen-Signalling Peptides L-Ascorbic (Gold Standard): NoPro-Helix C: Yes
Pro-Helix C combines two peptides: one that signals collagen repair and another that switches on the growth-factor pathway directly for firmer, more elastic skin.
SWITCH ON MORE THAN GLOW
Proven Results
Rigorously tested across all three dimensions of our Cell-to-Surface™ standard
BEFORE
AFTER 8 WEEKS
BEFORE
AFTER 8 WEEKS
BEFORE
AFTER 8 WEEKS
BEFORE
AFTER 8 WEEKS
BEFORE
AFTER 4 WEEKS
BASELINE
PRO-HELIX C AFTER BIOPSY
SEE THE DIFFERENCE RESULTS BEYOND VITAMIN C
TESTED AT THE CELL
MEASURED AT THE SURFACE
PERCEIVED IN THE MIRROR
Pro-Helix C
1. Tested at the Cellular Level
The Manchester Patch Test Assay & Spatial Transcriptomics
The Process
Manchester Patch Test Assay:
Intra-subject controlled, double-blinded study on human volunteers with skin biopsies taken and biomarkers examined under microscope. Validated & bench-marked against prescription product.
Spatial Transcriptomics:
After the patch test, the skin biopsies from treated and untreated sites are sliced wafer-thin and placed in the Xenium machine. It tags and images the RNA for 300 genes to show which genes switched on, in which cells, and exactly where in the skin.
The Purpose
Manchester Patch Test Assay:
Rapidly models 6 months of use on live human skin.
Spatial Transcriptomics:
Provides a precise map of how the product changed skin biology at the cellular level.
The Result
- Scientifically proven to increase fibrillin deposition in human skin
- 32% higher relative P4HA2 transcript abundance in superficial fibroblasts; increased in 5/5 donors in spatial transcriptomics
- Approximately 2.4-fold higher expression of the antioxidant enzyme gene SOD3 in spatial transcriptomics.
2. Measured on the Surface
Clinical Trial
The Process
32 people have baseline professional Visioscan & Skin Gloss Metre in controlled conditions to measure wrinkle depth & brightness, images are taken before using the product, at 7 days, 28 days and 56 days. Computer-measurements are taken and compared to the baseline.
The Purpose
A good study to see if visual improvements are obtained from use of the product.
The Results
- Clinically proven to reduce the appearance of fine lines & wrinkles from day 7
- Clinically proven to deliver an immediate boost to skin radiance maintained at 56 days
3. Perceived in the Mirror
Consumer Trial
The Process
45 people are provided with the product to use for 28 days, volunteers are asked questions about their experience at 0, 7 days, and 28 days.
The Purpose
This study is useful to understand volunteers' experience from product use, while it lacks rigorous scientific credentials, it helps to ensure that a person's experience aligns with the scientific results.
The Results
- 91% experienced brighter skin within 7 days.
- 87% said skin appeared firmer and more plump after use.
- 73% said they would switch from their current vitamin C product.
The Full Cell-to-Surface Range
Everything your skin needs to protect, repair, and restore.
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Night Repair Therapy
Regular price £135.00 GBPRegular priceSale price £135.00 GBP -
Age Defence
Regular price £92.00 GBPRegular priceSale price £92.00 GBP -
Pro-Helix C
Regular price £98.00 GBPRegular priceSale price £98.00 GBP -
The Complete Skin Ageing Duo
Regular price £227.00 GBPRegular priceSale price £227.00 GBP
A Complete Routine in Two Steps
Everything your skin needs to protect, repair, and restore.
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Night Repair Therapy
4.78 / 5.0
(186) 186 total reviews
Regular price £135.00 GBPRegular priceSale price £135.00 GBP -
Age Defence
4.71 / 5.0
(87) 87 total reviews
Regular price £92.00 GBPRegular priceSale price £92.00 GBP -
Pro-Helix C
5.0 / 5.0
(18) 18 total reviews
Regular price £98.00 GBPRegular priceSale price £98.00 GBP -
The Complete Skin Ageing Duo
4.76 / 5.0
(280) 280 total reviews
Regular price £227.00 GBPRegular priceSale price £227.00 GBP
As Featured In
Our Standard
Cell-to-Surface™
Most skincare is only tested on the surface. We believe our testing should match the ambition of our formulas. We independently validate the final formulation across three distinct dimensions:
Tested at the Cell
Tested at the Cell
Biological Validation
We measure deep beneath the surface to ensure the formula actively supports your skin’s long-term structural health.
Measured on the Surface
Measured on the Surface
Clinical Proof
We use advanced skin measurement instruments in independent trials to objectively track and quantify visible improvements.
Perceived in the Mirror
Perceived in the Mirror
Consumer Validation
Science only matters if you can see the difference. We use independent user panels to confirm our deep cellular research translates into real-world, visible confidence.
Discover Your Cellular Profile
Tell us what you are seeing on the surface. We will tell you what is happening at the cellular level, and how to support your skin's long-term health.
The Experts in Skin Ageing
125+ Years
Combined dermatological expertise
900+
Peer-reviewed scientific publications
Globally Renowned
Experts in molecular skin ageing
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Prof. Chris Griffiths OBE
Chief Scientist & Founder
Meet Prof. Griffiths
Professor Chris Griffiths OBE is one of the world’s most distinguished dermatologists. As part of the pioneering medical team that first showed how topical retinoids can repair mature skin, his decades of research form the clinical foundation of The Skin Diary. He translates deep molecular science into profound formulations.
Full Bio
Chris Griffiths is Emeritus Professor of Dermatology, University of Manchester, Adjunct Professor, King’s College London and a Consultant Dermatologist, King’s College Hospital. He qualified in medicine from St Thomas’ Hospital Medical School, London and trained in dermatology at St Mary’s Hospital, London and the University of Michigan before appointment to the Foundation Chair of Dermatology at The University of Manchester
He has received many international awards including In 2015, he received the Sir Archibald Gray Medal for outstanding service to British Dermatology, in 2016 the Society for Cosmetic Chemists Medal and in 2019 the British Society for Investigative Dermatology Medal for contributions to research. He is honorary member of 10 International Dermatology Societies
Chris was appointed OBE “for services to dermatology” in the 2018 Queen’s New Year Honours. He is a former President of the European Society for Dermatological Research, the European Dermatology Forum, the British Association of Dermatologists, and the International Psoriasis Council, which he co-founded in 2004.
Chris has published more than 850 scientific papers and is Editor-in-Chief of Rook’s Textbook of Dermatology and Rook’s Dermatology Handbook. He received a lifetime achievement award from the American Skin Association in 2009.
He was part of the team in Michigan that demonstrated that topical retinoids are efficacious in the management of ageing skin.
Professor Chris Griffiths and his team have provided strong support to the success of all generations of Boots No7 anti-ageing serums and the No7 skincare range as a whole.
Other Projects
Prof. Griffiths remains a leading, active voice in global dermatological health, dedicating his expertise to both academic research and humanitarian initiatives:
- The 2035 Psoriasis Mission: Having been part of the team that showed psoriasis to be an immune-mediated disease, he is actively leading research efforts with the ambition of finding a cure for the condition by 2035.
- Global Health & WHO Advocacy: As the Director of the Global Psoriasis Atlas, he played a pivotal role in successfully advocating for the World Health Organization (WHO) to add vital psoriasis biologic therapies to its Essential Medicines List, expanding access to care for thousands of people worldwide.
- The Burma Skincare Initiative: Driven by deep clinical empathy, he co-founded the Burma Skincare Initiative charity. This global partnership provides essential research, education, and clinical services to dermatologists and other healthcare workers in Myanmar, aiming to improve access to skincare for underserved populations, including children in orphanages.
- A Pillar of Medical Literature: He serves as the Editor-in-Chief of Rook's Textbook of Dermatology, the most authoritative medical reference book used by dermatologists globally. His profound impact on medical science is reflected in his status as the third most cited dermatologist in the world.
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Dr. Clare Kiely
Chief Medical Officer & Founder
Meet Dr. Kiely
Dr. Clare Kiely is a leading Consultant Dermatologist and highly specialised skin cancer surgeon. As a co-founder and the Chief Medical Officer of The Skin Diary, she brings together expertise in skin cancer science & clinically informed daily skincare. Her deep clinical understanding of how environmental damage impacts cellular health drives our mission to protect and fortify your skin for the long haul.
Full Bio
Clare Kiely is a Consultant Dermatologist, Dermatological and Laser surgeon in London. She is highly specialised in a wide range of dermatological issues, with a specific interest in photodamage, skin cancer, mohs micrographic surgery, acne, acne scarring, and aesthetic dermatology. She has completed fellowships in Dermato-oncology and Mohs surgery in St Johns institute of Dermatology where she is an Honorary consultant. She is also an honorary lecturer in skin ageing and aesthetics in the University of Manchester where she completed the her masters degree. She is current Chair of the Cosmetic Practice Standards Authority and is on the executive committee of the British Cosmetic Dermatology Group. Dr Kiely is an active researcher in skin cancer with numerous peer-reviewed publications. She is an expert in squamous cell carcinoma & has led the supra-specialty non-melanoma skin cancer team at Guys Hospital.She is an invited speaker nationally & internationally on skin cancer treatment, Mohs surgery, lasers, photo ageing treatments and aesthetics.
Other Projects
Dr. Kiely remains an active, leading voice in clinical practice, patient safety, and dermatological research:
- Patient Safety & Leadership: She is the current Chair of the Cosmetic Practice Standards Authority and serves on the Executive Board of the British Cosmetic Dermatology Group, working tirelessly to uphold the highest standards of clinical care across the industry.
- Surgical Excellence: She maintains a highly specialised clinical practice at prestigious institutions, including as a director of Skin Associates at The Lister Hospital and Spire Harpenden Hospital, focusing on the surgical management of complex skin cancers and advanced laser treatments.
- Academic Innovation: An active researcher with numerous peer-reviewed publications, she presents internationally on skin cancer treatment, photo-ageing, and lasers. She continues to pioneer gene-expression research and clinical trials in partnership with the University of Manchester.
- Medical Education: She has been directly responsible for the advanced training of national and international medical fellows in Mohs Micrographic
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Dr. Tamara Griffiths
Head of Innovation & Founder
Meet Dr. Griffiths
Dr Tamara Griffiths is a world-renowned Senior Consultant Dermatologist and the current President of the British Association of Dermatologists. As Head of Product Innovation at The Skin Diary, she leverages her unmatched expertise in skin ageing and aesthetic medicine to engineer formulations that deliver clinical-grade results while fiercely protecting the skin's barrier. She is a leading global advocate for patient safety and rigorous standards in the cosmetic sector.
Full Bio
Dr Griffiths has acted as advisor to the Department of Health’s Review of the Regulation of Cosmetic Interventions led by Sir Bruce Keogh published in 2013. She was instrumental in developing the Health Education England curricula and training frameworks for non-surgical cosmetic interventions (2015) and is a founding member and trustee of the Cosmetic Practice Standards Authority (CPSA), which launched in partnership with the Joint Council for Cosmetic Practitioners (JCCP) at the House of Lords in 2018. She is Medical Programme Director for the University of Manchester MSc in Skin Ageing and Aesthetic Medicine, which she founded in 2013 and now recognised as the gold standard in the UK and internationally, and is the Cosmetic Dermatology section editor for Rook’s Textbook of Dermatology.
Her clinical team was awarded BMJ Dermatology Team of the Year in 2018, and in 2021 she was recognised by the British Association of Dermatologists as Clinician of the Year. In July 2024 she commenced her two year term as President of the British Association of Dermatologists. In 2026, she was awarded the American Academy of Dermatology's Presidential Citation for her leadership, education and advocacy serving the profession and patients.
Other Projects
Dr Griffiths is a formidable force in dermatological education and has been instrumental in driving vital patient-safety regulations across the UK aesthetic arena:
- Pioneering Aesthetic Regulation: She acted as a key advisor to the Department of Health’s Review of the Regulation of Cosmetic Interventions (the Keogh Review) in 2013. Following this, she developed the Health Education England curricula and training frameworks for non-surgical cosmetic interventions in 2015.
- Setting the Gold Standard: To further protect the public, she is a founding member and trustee of the Cosmetic Practice Standards Authority (CPSA), which launched in partnership with the Joint Council for Cosmetic Practitioners (JCCP) at the House of Lords in 2018.
- Educational Leadership: She is the Medical Programme Director for the University of Manchester MSc in Skin Ageing and Aesthetic Medicine, aprogramme she founded in 2013 that is now recognised globally as the educational gold standard in the field. Additionally, after launching the BAD's British College of Dermatology in 2021, she was appointed as its inaugural Education Vice President in 2023
- National and International Leadership: In July 2024, she commenced her two-year term as President of the British Association of Dermatologists, guiding the future of the profession and championing standards in research, education and clinical practice across the UK.She was awarded the Presidential Citation by the American Academy of Dermatology, for her contribution to leadership in dermatology practice, education and advocacy work in cosmetic dermatology regulation.
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Dr. Richard Barlow
Chair of Advisory Board & Founder
Meet Dr. Barlow
Dr Richard Barlow is a Consultant Dermatologist with over 25 years of clinical expertise. As a sub specialist in skin cancer management and cosmetic dermatology, he brings a profound understanding of how to protect, preserve, and renew the skin's structural integrity. His decades of surgical and clinical experience ensure that The Skin Diary formulations meet the highest possible medical standards, delivering exceptional care without compromise.
Full Bio
With over 25 years of experience, he has been a Consultant Dermatologist at St John’s Institute of Dermatology since 1996 and during this time served on the Joint Tumour Service at Moorfields Eye Hospital.
Specialising in skin cancer management, including Mohs’ surgery, cutaneous laser surgery, and cosmetic dermatology, he is a distinguished figure in the field. He was the Founding President of the British Cosmetic Dermatology Group and President of St John's Dermatology Society in 2009/10.
His contributions include representing the BAD and BCDG at what was then the British Academy of Cosmetic Practice 2007 to 2016.
Other Projects
Dr Barlow is a recognised pioneer and leader within the UK's dermatological and aesthetic communities, having dedicated much of his career to elevating clinical standards:
- Founding Leadership: He was the Founding President of the British Cosmetic Dermatology Group (BCDG), playing a vital role in shaping the standards of safe, effective aesthetic medicine across the UK.
- Clinical Governance: He served as the President of the St John's Dermatology Society in 2009/10, guiding and representing one of the most respected dermatological associations in the country.
- National Representation: Showcasing his influence at a national level, he represented the British Academy of Cosmetic Practice as a joint representative for both the BAD (British Association of Dermatologists) and the BCDG from 2007 to 2016, ensuring that clinical safety always remains at the forefront of cosmetic care.
Pure Science. Proven Results
Real Results
3.7x Reduction in Collagen Damage
3.7x Reduction in Collagen Damage
Our Age Defence day cream demonstrated a 3.7x reduction in collagen damage and a 3.8x reduction in inflammation markers when exposed to UV in an independent gene expression study.
2x Increase in Collagen
2x Increase in Collagen
Night Repair Therapy was independently tested via the Manchester Patch Test Assay showing a 2x Increase in collagen and fibrillin.
20x More Effective Cellular Support
20x More Effective Cellular Support
In the Manchester Patch Test Assay Night Repair Therapy outperformed the gold standard (prescription control). Equivalent of 20x more effective than retinol.
98% Agreed our Formulas were Gentle on Skin
98% Agreed our Formulas were Gentle on Skin
We formulate each product with a synergy of ingredients designed to provide profound results without compromising the skin barrier. Night Repair Therapy is a prime example, the outperforming results came without irritation.
Invest in Your Skin. Get Rewarded.
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