Name: C-Tetra 30ml
Rating: 4.9 (871 reviews)

KEY BENEFITS

Increased Skin Youthfulness

Proven to simultaneously smooth the look of fine lines and wrinkles while visibly boosting skin glow and radiance.
Brighter, More Even Complexion

Proven to visibly brighten the skin tone, for a more even and healthy-looking skin appearance.
Lightweight Nourishment

This jojoba (pronounced 'huh-hoh-ba') seed oil-based formula delivers effective yet non-greasy nourishment for visibly softer and comforted skin.

PROVEN RESULTS

7 days to restored skin radiance and visibly brighter skin*
96% of sensitive skins agreed C-Tetra was gentle on the skin*
4 weeks to visibly reduced wrinkles & dark spots*
90% agree skin feels instantly softer*

*Proven via independent consumer study conducted over 4 weeks on 52 participants with sensitive skin.

HOW TO USE

STEP 1

After cleansing in the morning, massage 4 drops across the face, neck and décolletage.

STEP 2

Leave to absorb before applying sunscreen. We recommend Advanced Day Ultimate Protect.

LOVED & RECOMMENDED

Softens visible ageing concerns while being tolerable for all.

BRIDGET MARCH

Digital Beauty Director - Harper's Bazaar
My wrinkles have almost disappeared!

TATIANA S

Verified Medik8 Customer

KEY INGREDIENTS

7% Stabilised Vitamin C (tetrahexyldecyl ascorbate)

A low-irritation form of vitamin C that delivers exceptional antioxidant protection against harmful free radical damage while brightening for a visibly even, more youthful-looking complexion.
Vitamin E

A powerful antioxidant that provides additional antioxidant protection against the ageing effects of free radicals. It also helps to boost the power of vitamin C for optimum visible results.
Full Ingredients

THE SCIENCE BEHIND THE FORMULA

Ultra-gentle & perfect for visibly radiant skin

DANIEL ISAACS Chief Product Officer

It is exceptionally difficult to formulate a vitamin C serum that will retain its power over time. That's because vitamin C is notoriously unstable, meaning its effectiveness can be compromised when it comes into contact with light, heat or air.

That's why we have chosen to formulate C-Tetra with an extremely stable form of vitamin C (tetrahexyldecyl ascorbate), so you can be sure that your vitamin C is still as potent and effective 12 months after you first opened it.

GOOD TO KNOW

["NO ARTIFICIAL FRAGRANCE"
"NO SYNTHETIC COLOURS "
"PARABEN FREE"
; CERTIFIED BY THE VEGAN SOCIETY"]

FAQS

What's the difference between C-Tetra and C-Tetra Luxe?

+
C-Tetra is our original, best-selling vitamin C serum. It's the perfect option for those who are new to vitamin C or those with sensitive skin, who still want visible age-defying results. C-Tetra Luxe is our supercharged vitamin C serum - ideal for those looking for clinical brightening and nourishing power. Both serums are formulated with stabilised tetrahexyldecyl ascorbate.
Can I use C-Tetra alongside vitamin A?

+
Absolutely. In fact we recommend it as part of our pioneering CSA Philosophy which champions vitamin C plus sunscreen by day, vitamin A by night as the simple secret to glowing, youthful-looking skin.
Can I use C-Tetra if I'm pregnant or breastfeeding?

+
As a cosmetics company, we are unable to provide product advice in relation to medical conditions such as pregnancy. We would 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 to avoid during pregnancy, unless advised by your doctor.

C-Tetra 30ml

871 Reviews

DERMATOLOGIST RECOMMENDED

CLINICAL RESULTS

AGE-DEFYING EXPERTS

MADE IN THE UK

B CORP CERTIFIED

REVIEWS

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4.9 871 Reviews, 39 Q&As

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871 Reviews

Updating Results

05/17/25

J

Jade C.

05/15/25

Lovely product, feels really nice

Lovely product, feels really nice when applied to the skin and definitely makes my skin look brighter and my complexion look more even.
I wouldn’t use another product goods forward

E

Elena M.

05/14/25

The best serum

I'm in. love with the vit C serum. It leaves my skin so soft and i can see the change which is better than before.

A

Agata N.

05/13/25

Really good!

Feels lovely on the skin and I've noticed a difference in my skin, it looks less dull!

M

Menisha K.

05/12/25

I have been using this

I have been using this product for 4 months now I can see a difference in my face and neckline
Less visible sun damage and more clear and soft skin

G

Gemma M.

05/11/25

Clearer, softer skin

Absolutely love this product. My skin is a lot clearer, softer and feels more moisturised. Would highly recommend.

E

Emma

11/22/24

Q: Hi there, can you use the C-Tetra with the Hyrd8 B5? If so, which should go on first? Thanks.

Medik8

12/06/24

A: Hi Emma, thank you for your question! Yes, you can absolutely apply the Hydr8 B5 serum, before your C-Tetra serum to provide your skin with an extra boost of hydration. This layering ensures your skin stays hydrated while reaping the benefits of vitamin C. Thanks, Medik8 Team

J

Jane

09/05/24

Q: How much C-Tetra should Ii use (I put it on in the morning after cleansing and before moisturiser)? It says the bottle should last up to 6 months but mine lasts about 6 weeks (full size) so I'm wondering if I'm using too much?

Medik8

10/07/24

A: Hi Jane, thanks for your question about our C-Tetra! For best results, we recommend around 4-6 drops applied to the face, neck and decolletage (avoiding the eye area directly) and slightly less if you aren't applying to the decolletage for example. Each bottle when used as directed contains up to 200 applications. We hope this helps! Thanks, Medik8.

A

Amanda

03/17/24

Q: Can you wear this in the sun?

Medik8

06/21/24

A: Hi Amanda, thanks for your question! Stabilised vitamin C (as you will find in all Medik8 vitamin C products) will not cause photosensitivity! In fact, vitamin C can actually boost your skin's protection against the sun when applied underneath a sunscreen. Thanks, Medik8.

V

Victoria

01/11/24

Q: How do I use this with hydr8 b5 please.

Medik8

06/22/24

A: Hi Victoria, for best results apply Hydr8 B5 (water-based serum) before C-Tetra (oil-based serum) followed by your moisturiser and sunscreen. Thanks, Medik8.

M

Mariia

12/05/23

Q: Hi! Can I use Daily Radiance Vit C moisturizer over the top of C/Terra serum? Whether it can be used during breastfeeding?

Medik8

10/08/24

A: Hello Mariia,

We do not recommend applying two Vitamin C products in the same regimen as this may cause irritation to the skin. Also Unfortunately, as a cosmetic brand, we are unable to provide specific medical advice relating to our products. We would strongly advise speaking with your GP or Midwife so that they can give you an accurate recommendation. The full ingredients list for each of our products can be found on the product pages of the Medik8 website.

However, for general guidance, the main ingredient we recommend avoiding during pregnancy or nursing is vitamin A; found in Intelligent Retinol, Crystal Retinal, any r-Retinoate and Intelligent Retinol Smoothing Night Cream. We also recommend avoiding using Smooth Body Lotion during pregnancy/nursing.

Please let us know if you have any further questions.

Thanks, Medik8

C-Tetra 30ml

Lipid 7% Vitamin C Radiance Serum Full Details

Sorry, this product is currently out of stock

KEY BENEFITS

Increased Skin Youthfulness

Brighter, More Even Complexion

Lightweight Nourishment

PROVEN RESULTS

HOW TO USE

STEP 1

STEP 2

LOVED & RECOMMENDED

KEY INGREDIENTS

THE SCIENCE BEHIND THE FORMULA

GOOD TO KNOW

FAQS

What's the difference between C-Tetra and C-Tetra Luxe?

Can I use C-Tetra alongside vitamin A?

Can I use C-Tetra if I'm pregnant or breastfeeding?

Complete Your Regime

REVIEWS

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