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Defend against premature skin ageing and achieve accelerated skin brightening with a next-generation combination of 20% vitamin C and skin barrier science.

Clinically proven to brighten skin and visibly improve wrinkles in 7 days^[1]with 0% barrier disruption^[1], C-Tetra Advanced is engineered for high-performance visible brightening, skin smoothing, and daily antioxidant defence.

This intelligent ingredient complex combines potent, stabilised 20% vitamin C with restorative phyto exosomes for enhanced skin resilience and omni-antioxidant acetyl zingerone to neutralise the ageing effects of free radicals.

The result? A high-performance, age-defying vitamin C serum that works smarter, not harsher.

KEY BENEFITS

Dramatic Skin Brightening

Clinically proven to visibly brighten skin and even tone in 7 days for a radiant, luminous complexion.^[1]
Enhanced Skin Barrier Support

Powerful phyto exosomes deliver replenishing bioactives to skin cells rapidly & effectively, ensuring 0% barrier disruption.^[1]
Premature Skin Ageing Defence

Shields skin from damaging free radicals, pollution, and daily environmental stressors to help defend against premature skin ageing.
Smooth & Even Complexion

Clinically proven to visibly improve skin smoothness and texture in 7 days, leaving a soft, polished finish.^[1]
Lightweight Finish

The fast-absorbing gel-serum texture hydrates, smooths, and primes, leaving skin instantly refreshed and ready for the day ahead.

PROVEN RESULTS

7 days to visibly brighter skin^[1]
7 days to visibly reduced wrinkles^[1]
0% barrier disruption^[1]
7 days to visibly smoother skin texture^[1]
90% reduction of pollution damage to the skin’s surface^[2]

[1] Proven via independent clinical study conducted over 4 weeks on 32 participants. [2] Proven via in vitro protein carbonylation data against particulate matter pollution on the stratum corneum and epidermis. [3] Proven via in vitro protein carbonylation study using European standard reference environmental pollutants.

HOW TO USE

Apply as part of your morning skincare routine. Massage 2-3 pumps across the face, neck and décolletage. Follow with moisturiser and always finish with sunscreen.

LOVED & RECOMMENDED

With this kind of Vitamin C percentage, you're going to get maximum brightness to the skin in just 7 days.

Dr Ewoma Ukeleghe

Medical & Cosmetics Doctor & Medik8 Global Ambassador
It’s rare to see such a powerful brightening treatment that also strengthens and supports skin health from within - this does both.

Dr Bibi Ghalaie

Cosmetic Physician & Medik8 Global Ambassador
Love this new product! I have noticed a glow in just a few days and my skin's looking a lot brighter.

Danielle

Verified Medik8 Customer

KEY INGREDIENTS

20% Stabilised Vitamin C (Tetrahexyldecyl Ascorbate)

A highly potent yet gentle form of vitamin C for dramatic skin brightening and powerful antioxidant protection against premature skin ageing.
Phyto Exosomes

Encapsulated by nature, our phyto exosomes intelligently deliver proteins, lipids, and messenger molecules to skin cells. Together, alongside our supercharged vitamin C, they help prevent & reduce premature skin ageing by supporting healthier-looking, more resilient skin.
Acetyl Zingerone (pronounced ‘a-sea-tul’)

A super-antioxidant that works synergistically with vitamin C, enhancing its efficacy while neutralising ageing free radicals and shielding skin from environmental stressors.
Multi-Weight Hyaluronic Acid

Draws moisture into the skin to instantly plump and deeply hydrate for a soft, supple complexion.
N-Acetyl Glucosamine (NAG)

A barrier-supporting, gentle, skin-refiner that smooths the look of pores while helping to increase the skin’s own natural hyaluronic acid levels over time.
Full Ingredients

THE SCIENCE BEHIND THE FORMULA

C-Tetra Advanced combines the potent power of vitamin C with barrier-supporting phyto exosomes alongside superantioxidant acetyl zingerone, to protect against premature skin ageing. C-Tetra Advanced is scientifically proven to shield against the environmental stressors that cause premature skin ageing, reducing damage by up to 78%.^[3]

Daniel Isaacs Chief Product Officer

Traditional high-strength vitamin C serums can degrade before reaching the skin or cause irritation. C-Tetra Advanced is meticulously formulated with a 20% stabilised vitamin C complex, ensuring long-lasting potency from the first drop to the last.

Encapsulated by nature and sourced from green tea leaves, phyto exosomes are rich in proteins, lipids, and messenger molecules. Acting as intelligent micro-carriers they carry key signalling molecules, like peptides and nutrients, to send signals to skin cells to help reinforce the skin barrier for optimal skin tolerance and comfort.

Further fortified by omni-antioxidant acetyl zingerone, the next-generation formula helps shield skin from pollution-induced damage by neutralising free radicals, blocking harmful pollution particles, and strengthening the skin’s natural defences for increased skin resilience.

SUSTAINABILITY CLAIMS

Provenance provides confidence for sustainability claims; helping to prevent ‘green-washing’ and empowering conscious consumers to purchase in line with their values. Provenance ‘Proof Points’ are all third party verified and evidenced through supply chains.

GOOD TO KNOW

CLINICALLY PROVEN
ARTIFICIAL FRAGRANCE FREE
DERMATOLOGICALLY TESTED
PROVEN GENTLE FORMULA
CERTIFIED BY THE VEGAN SOCIETY
NON-COMEDOGENIC
TESTED ON ALL SKIN TYPES & TONES

FAQS

What strength vitamin C is C-Tetra Advanced?

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C-Tetra Advanced contains 20% stabilised vitamin C (tetrahexyldecyl ascorbate).
Can I use C-Tetra Advanced alongside Crystal Retinal (vitamin A)?

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Absolutely. We recommend it as part of our pioneering CSA Philosophy^Ⓡ which champions vitamin C plus sunscreen by day, and vitamin A by night as the simple secret to glowing, youthful-looking skin.
Can I use C-Tetra Advanced if I am pregnant or breastfeeding?

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As a cosmetics company, we are unable to provide product advice for medical conditions such as pregnancy or breastfeeding. We strongly recommend discussing the ingredients with your GP or midwife before use. As general guidance, this product does not contain any ingredients which we would recommend avoiding during pregnancy unless advised by your doctor.
Can I layer C-Tetra Advanced with Liquid Peptides Advanced MP in the morning?

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Yes, you can. C-Tetra Advanced and Liquid Peptides Advanced MP are both emulsion-based serums however C-Tetra Advanced is slightly thicker in texture. We recommend applying serums in order of thinnest to thickest consistency. Therefore apply Liquid Peptides Advanced MP first and then apply C-Tetra Advanced.
Does C-Tetra Advanced contain fragrance/essential oils?

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C-Tetra Advanced is free from artificial fragrances but does contain a natural, uplifting citrus fragrance derived from essential oils. The scent is refreshing and is designed to enhance your experience and offer an energising start to your morning skincare routine. If you are familiar with our C-Tetra and C-Tetra Luxe serums, you can expect to smell the same scent.
Where do I layer C-Tetra Advanced in my routine?

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C-Tetra Advanced should be applied in the morning, after cleansing and toning, but before moisturiser and sunscreen. If you are using multiple serums, we recommend applying them in order of thinnest to thickest in texture. Since C-Tetra Advanced is an emulsion, it should be layered on top of water and oil-based serums. This ensures your skin gets the full benefits of each product.
Can I use C-Tetra Advanced if I’ve never used vitamin C before?

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Absolutely. Although C-Tetra Advanced contains a potent 20% vitamin C, it has been formulated using a very gentle form of vitamin C called THDA (Tetrahexyldecyl Ascorbate) that is suitable for all skin types, even if you’re new to vitamin C. Alongside this, it contains many gentle actives such as phyto exosomes, which offer soothing properties to support the skin barrier. C-Tetra Advanced is also proven to be gentle on all skin types in independent clinical and consumer testing. This means anyone can enjoy C-Tetra Advanced without fear of irritation.
I think there’s product left in my bottle that I can’t access with the pump. What do I do?

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As C-Tetra Advanced is a lightweight emulsion, it is a little thicker than water-based serums and therefore may flow more slowly, however, it was designed for use with a pump so it should still dispense with ease. If there is any residue that the pump is not dispensing, you can unscrew the pump and turn the bottle upside down to pour out any remaining product. This should not be required unless you have used up nearly all of the product.

C-Tetra® Advanced

Name: C-Tetra® Advanced
Brand: Medik8
SKU: P11807
Price: 69.00 GBP
Availability: InStock
Rating: 4.8 (657 reviews)

20% Vitamin C Gel-Serum With Phyto Exosomes Full Details

Size: 30ml

Product variants

C-Tetra® Advanced

The Vitamin C Serum Range

Strength
	AM C-Tetra®	AM C-Tetra® Luxe	NEWAM C-Tetra® Advanced	AM Super C Ferulic™
Strength	Strength 7% Stabilised Vitamin C	Strength 14% Stabilised Vitamin C	Strength 20% Stabilised Vitamin C	Strength 30% Stabilised Vitamin C
Texture
Texture	Texture Lightweight oil	Texture Rich oil	Texture Lightweight Gel-Serum	Texture Rich, oil like serum
Skin Types
Skin Types	Skin Types New to Vitamin C, Sensitive skin	Skin Types All skin types, First signs of ageing	Skin Types All skin types, Visible signs of ageing	Skin Types Advanced signs of sun induced ageing
Benefits
Benefits	Benefits Brightening Nourishing	Benefits Brightening Nourishing Antioxidant Protection	Benefits Brightening Defends Against Premature Skin Ageing Visibly Improves Wrinkles Smooths Skin Texture 0% Barrier Disruption	Benefits Brightening Age Reversal Dark Spot Reduction
Key Ingredients
Key Ingredients	Key Ingredients 7% Tetrahexyldecyl Ascorbate Vitamin E	Key Ingredients 14% Tetrahexyldecyl Ascorbate Squalane Maracuja Oil	Key Ingredients Phyto Exosomes 20% Tetrahexyldecyl Ascorbate Acetyl Zingerone	Key Ingredients 30% Ethylated L-Ascorbic Acid Ferulic Acid Vitamin E Turmeric Root Extract

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KEY BENEFITS

Dramatic Skin Brightening

Enhanced Skin Barrier Support

Premature Skin Ageing Defence

Smooth & Even Complexion

Lightweight Finish

PROVEN RESULTS

HOW TO USE

LOVED & RECOMMENDED

KEY INGREDIENTS

THE SCIENCE BEHIND THE FORMULA

SUSTAINABILITY CLAIMS

GOOD TO KNOW

FAQS

What strength vitamin C is C-Tetra Advanced?

Can I use C-Tetra Advanced alongside Crystal Retinal (vitamin A)?

Can I use C-Tetra Advanced if I am pregnant or breastfeeding?

Can I layer C-Tetra Advanced with Liquid Peptides Advanced MP in the morning?

Does C-Tetra Advanced contain fragrance/essential oils?

Where do I layer C-Tetra Advanced in my routine?

Can I use C-Tetra Advanced if I’ve never used vitamin C before?

I think there’s product left in my bottle that I can’t access with the pump. What do I do?

C-Tetra® Advanced

20% Vitamin C Gel-Serum With Phyto Exosomes Full Details

The Vitamin C Serum Range

Crystal Retinal®

Crystal Retinal

Crystal Retinal®

Crystal Retinal®

Crystal Retinal®

Crystal Retinal®

Crystal Retinal®

Crystal Retinal®

Crystal Retinal®

Crystal Retinal®

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