Medik8C-Tetra
Product Description
Restore the look of skin radiance in just 7 days* with cult-favourite C-Tetra.
Formulated with a stabilised form of vitamin C (7%) called tetrahexyldecyl ascorbate (pronounced 'tetra-hexul-deckul as-CORR-bate'), this lightweight serum works to visibly brighten uneven skin tone and reduce the look of fine lines and wrinkles, while remaining gentle on sensitive skin.
Fortified with vitamin E, this antioxidant powerhouse also protects the skin against the ageing and damaging effects of free radicals for a more youthful and healthy-looking complexion overall. The perfect option for those who are new to vitamin C, or those with sensitive skin.
*Proven via independent consumer study conducted over 4 weeks on 52 participants with sensitive skin.
KEY BENEFITS
Increased Skin Youthfulness
Proven to smooth the appearance of fine lines and wrinkles and visibly boost skin's radiance in 7 days*
*Proven via independent consumer study conducted over 4 weeks on 52 participants with sensitive skin.
Brighter, More Even Complexion
Proven to visibly brighten the skin in 7 days* and reduce the appearance of wrinkles & dark spots in 4 weeks*
*Proven via independent consumer study conducted over 4 weeks on 52 participants with sensitive skin.
Gentle, Lightweight Nourishment
The jojoba seed oil-based formula delivers non-greasy yet effective nourishment for visibly comforted and softer skin.
87% of sensitive skins agree this is the most gentle vitamin C serum they have ever used*
96% of sensitive skins agreed C-Tetra was gentle on the skin*
*Proven via independent consumer study conducted over 4 weeks on 52 participants with sensitive skin.
KEY INGREDIENTS
Stabilised Vitamin C (tetrahexyldecyl ascorbate)
This stable, low-irritation form of vitamin C is incredibly effective on the skin; delivering exceptional protection against ageing free radicals. Supporting collagen production and brightening the skin tone, it leaves the complexion visibly more even, radiant and youthful-looking.
Vitamin E
Rich in antioxidants, vitamin E helps to protect the skin against ageing free radicals. It also helps to boost the power of vitamin C for maximum visible results.
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.
NO ARTIFICIAL FRAGRANCE
NO SYNTHETIC COLOURS
PARABEN FREE
CERTIFIED BY THE VEGAN SOCIETY
Formulated with a stabilised form of vitamin C (7%) called tetrahexyldecyl ascorbate (pronounced 'tetra-hexul-deckul as-CORR-bate'), this lightweight serum works to visibly brighten uneven skin tone and reduce the look of fine lines and wrinkles, while remaining gentle on sensitive skin.
Fortified with vitamin E, this antioxidant powerhouse also protects the skin against the ageing and damaging effects of free radicals for a more youthful and healthy-looking complexion overall. The perfect option for those who are new to vitamin C, or those with sensitive skin.
*Proven via independent consumer study conducted over 4 weeks on 52 participants with sensitive skin.
KEY BENEFITS
Increased Skin Youthfulness
Proven to smooth the appearance of fine lines and wrinkles and visibly boost skin's radiance in 7 days*
*Proven via independent consumer study conducted over 4 weeks on 52 participants with sensitive skin.
Brighter, More Even Complexion
Proven to visibly brighten the skin in 7 days* and reduce the appearance of wrinkles & dark spots in 4 weeks*
*Proven via independent consumer study conducted over 4 weeks on 52 participants with sensitive skin.
Gentle, Lightweight Nourishment
The jojoba seed oil-based formula delivers non-greasy yet effective nourishment for visibly comforted and softer skin.
87% of sensitive skins agree this is the most gentle vitamin C serum they have ever used*
96% of sensitive skins agreed C-Tetra was gentle on the skin*
*Proven via independent consumer study conducted over 4 weeks on 52 participants with sensitive skin.
KEY INGREDIENTS
Stabilised Vitamin C (tetrahexyldecyl ascorbate)
This stable, low-irritation form of vitamin C is incredibly effective on the skin; delivering exceptional protection against ageing free radicals. Supporting collagen production and brightening the skin tone, it leaves the complexion visibly more even, radiant and youthful-looking.
Vitamin E
Rich in antioxidants, vitamin E helps to protect the skin against ageing free radicals. It also helps to boost the power of vitamin C for maximum visible results.
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.
NO ARTIFICIAL FRAGRANCE
NO SYNTHETIC COLOURS
PARABEN FREE
CERTIFIED BY THE VEGAN SOCIETY
Directions
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.
How to Layer C-Tetra
AM: Apply C-Tetra after cleansing and toning in your morning skincare routine. Always follow with sunscreen.
More information
*Product packaging may vary by region\n\nIngredients
Simmondsia Chinensis (Jojoba) Seed Oil, Cyclopentasiloxane, Cyclohexasiloxane, Tetrahexyldecyl Ascorbate, Citrus Grandis (Grapefruit) Peel Oil, Tocopheryl Acetate, Limonene, PPG-12/SMDI Copolymer, Citral, Linalool, Geraniol.
This list of ingredients may be subject to change, please consult the packaging of the product purchased.
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Rated 5 out of
5
by
Magda W. from
Good quality and stable C
[This review was collected as part of a promotion.] Great skincare. Good for base before day cream moisturiser.
Date published: 2026-06-05
Rated 5 out of
5
by
Tetiana D. from
The ultimate glow booster!
[This review was collected as part of a promotion.] I’ve been using this advanced Vitamin C serum for a while now, and it has done wonders for my skin. The texture is beautiful—it feels silky, absorbs quickly, and doesn't leave any greasy film. It layers perfectly and a great combo under my daily sunscreen and makeup without causing any pilling or heaviness. Since adding it to my morning routine the surface of my skin is great, my complexion has become incredibly bright, even-toned, and radiant. It really helps to fade dark spots and gives that healthy, fresh glow. An absolute must-have for antioxidant protection!
Date published: 2026-06-05
Rated 5 out of
5
by
Mrs S. from
I’ve been using Medik8 C-Tetra
[This review was collected as part of a promotion.] I’ve been using Medik8 C-Tetra for a few weeks and love the results. It’s lightweight, absorbs quickly, and is gentle enough for daily use. It smells gorgeous, hasn’t caused any irritation, and fits perfectly into my morning skincare routine. A great vitamin C serum that I’d happily buy again.
Date published: 2026-06-05
Rated 5 out of
5
by
Shirlee S. from
Can’t be without
[This review was collected as part of a promotion.] Well this vitamin c speaks for itself, I actually had a few age marks on my face they are now almost completely gone, I feel it’s definately down to this c tetra, I just love it and my friends always ask me what I use I just tell them Medik 8 cos it’s the best, vitamin c is a must I believe and will never be without it
Date published: 2026-06-01
Rated 5 out of
5
by
Lorna U. from
Vitamin C serum
[This review was collected as part of a promotion.] Absolutely love this product. Tried a few different vitamin C serums and for me this is worth the price. Love it.
Date published: 2026-06-01
Rated 5 out of
5
by
Yasmin S. from
Gentle serum
[This review was collected as part of a promotion.] This was the first time I’ve purchased a vitamin C and this was an ideal start. There’s been minimal to no sensitivity. Long term, I feel my skin is softer and brighter, and I’m pleased.
The serum does not feel oily at all and absorbs quickly. For the colder months, I might try to use a richer formula as my skin tends to get drier .
Date published: 2026-05-31
Rated 4 out of
5
by
Andrea A. from
This serum has a watery,
[This review was collected as part of a promotion.] This serum has a watery, but still oily, texture. It does run well in the face and neck. As I am over 50 I really need a higher vitamin C concentration but started with this because I have sensitive skin. I make sure to apply it once my skin has dried from clearing and before moisturizer.
Date published: 2026-05-22
Rated 1 out of
5
by
Lee W. from
Cracking for all the wrong reasons
[This review was collected as part of a promotion.] Very disappointed as the lid cracked on the lid first time I used
Date published: 2026-05-22
Can I use this serum under eyes?
Yes absolutely!
Date published: 2023-05-24
What % vitamin c?
The tetrahexyldecyl ascorbate (Vitamin C) in C-Tetra serum is 7%.
Date published: 2023-05-24
What percentage of vitamin c does this contain?
30%
Date published: 2023-03-04
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