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C-Tetra

Medik8 C-Tetra 30ml

%0 4.74 | 1044 reviews
Box

£45.00 (£1.50 per ml)

In stock

If you like we can let you know when we have some more.

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

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\n

Ingredients

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 2 out of 5 by from Not for me. [This review was collected as part of a promotion.] This product didn’t work for my skin type. I have sensitive combination skin, and my pores can easily become blocked. I’m not sure if it’s down to a particular ingredient, but after using it as directed, it gradually caused my pores to become severely blocked and led to a breakout. To avoid throwing it away, I’m now using it on my neck and hands.
Date published: 2026-06-08
Rated 5 out of 5 by from Love the smell! Spa! [This review was collected as part of a promotion.] I have been coming back to this for years! Wonderful product and smell is beautiful!
Date published: 2026-06-08
Rated 5 out of 5 by from C-Tetra is a stable in [This review was collected as part of a promotion.] C-Tetra is a stable in my morning routine. Sinks in to my skin beautifully, love it !!!
Date published: 2026-06-06
Rated 5 out of 5 by from I have been using Medik8 [This review was collected as part of a promotion.] I have been using Medik8 C-Tetra for years and it is the first vitamin C serum that hasn’t broken me out or irritated my skin. It layers perfectly under my morning moisturiser and SPF without any pilling. My skin looks noticeably brighter, plumper, and has a healthy, subtle glow.
Date published: 2026-06-06
Rated 4 out of 5 by from C tetra [This review was collected as part of a promotion.] I love Medik8 products, but unfortunately the top squeeze part of this bottle came away from the lid. The product is great, but the packaging was faulty.
Date published: 2026-06-05
Rated 5 out of 5 by 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 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 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
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Can I use this serum under eyes?

Asked by: Anonymous
Yes absolutely! 
Answered by: Anonymous
Date published: 2023-05-24

What % vitamin c?

Asked by: Anonymous
The tetrahexyldecyl ascorbate (Vitamin C) in C-Tetra serum is 7%.
Answered by: Anonymous
Date published: 2023-05-24

What percentage of vitamin c does this contain?

Asked by: Anonymous
30%
Answered by: Anonymous
Date published: 2023-03-04
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