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.
See more...
Rated 5 out of
5
by
Kelly-Dee from
Great Vit C
Love this vitamin c... I was dubious at first with such a watery texture, but soaks in really quick and really helps to brighten my skin.
Date published: 2026-10-30
Rated 5 out of
5
by
Stephanie T. from
I love this lightweight serum
[This review was collected as part of a promotion.] I've been using this serum for at least ten years and I love it. It isn't at all greasy and sinks into my skin within seconds, leaving it feeling smooth and silky. I've been told I have lovely skin for my age and I'm sure this serum has contributed to this.
Date published: 2026-10-28
Rated 5 out of
5
by
Shorlen C. from
Leave skin soft and complexion
[This review was collected as part of a promotion.] Leave skin soft and complexion radiant. Great addition to my skincare routine.
Date published: 2026-10-28
Rated 3 out of
5
by
Erin from
On the fence
[This review was collected as part of a promotion.] I’m on the fence with this one - I am reintroducing vitamin c to my routine after years of sensitivity/irritation due to rosacea, and this causes zero irritation which is brilliant. This is my first bottle so TBD on longterm effects.
However, this just doesn’t sit well under makeup - I am greasy within a few hours, no matter what foundation or how much setting powder I use; add any SPF on top, too, and it’s like a slip n’ slide. I’ve tried different products (medik8 and others) and it’s all the same, with varying levels of shine. Someone help?!
Also, the twist topper broke within a few weeks because I tightened it too hard. I’ve never had this happen and for the price, I expect better quality. Probably lessened the efficacy but still using it up anyway in a different container.
Date published: 2026-10-28
Rated 5 out of
5
by
Alex M. from
Lovely serum
[This review was collected as part of a promotion.] Velvet soft serum. Very pleased with this product and to incorporate it into my morning routine.
Date published: 2026-10-28
Rated 5 out of
5
by
Tatiana I. from
Seeing the difference
[This review was collected as part of a promotion.] Love this product so much. Must have in your routine
Date published: 2026-10-22
Rated 5 out of
5
by
Kate S. from
10/10 no complainants
[This review was collected as part of a promotion.] Great serum, smooth and silky texture without leaving residue.
Date published: 2026-10-18
Rated 5 out of
5
by
Tara K. from
Amazing product!
[This review was collected as part of a promotion.] Was recommended this product by my beatuy lady and I must say she was right it’s an amazing product it’s not heavy on my face and doesn’t leave it sticky like some other products do ! Would highly recommend it !!
Date published: 2026-10-14
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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