BurgerClosechevronBagSearchUser
  • Delivery country: United Kingdom
  • servicesStores & services
    Belfast, Victoria Square
    Stores
    Sephora Belfast, Victoria Square
    Victoria Square, Bridge St, Belfast, BT1 4QG
    View All Hours +
    Cycle
    Change your store

    Your favourite store allows you to see services available and book appointments

    In-Store Services
    Make-up and skincare services, Benefit BrowBar, gifting and personalisation workshop, Sephora offers you a whole range of services to come and discover in store Make an appointment
    (Belfast, Victoria Square)
    See Belfast, Victoria Square store servicesView all stores
  • Wishlist
  • Cart0
C-Tetra®

Medik8 C-Tetra® 30ml

%0 4.74 | 1025 reviews
Box

£45.00 (£1.50 per ml)

Free UK delivery

In stock

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

Product Description

Restore the appearance of skin radiance in just 7 days* with Medik8’s cult favourite C-Tetra serum.

Expertly formulated by their skincare experts with a stabilised form of vitamin C (tetrahexyldecyl ascorbate ), this lightweight serum reduces the appearance of fine lines and wrinkles and visibly brightens uneven skin tone - all while remaining gentle on sensitive skin.

The addition of antioxidant-rich vitamin E protects the skin against the damaging and ageing effects of free radicals for a more healthy, youthful-looking complexion overall. The perfect daily serum for those who are new to vitamin C, or have 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.

Proven Results:
7 days to restored skin radiance*
7 days to visibly brighter
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.

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.

Good to Know:
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.

Ingredients

Simmondsia Chinensis (Jojoba) Seed Oil, Cyclopentasiloxane, Cyclohexasiloxane, Tetrahexyldecyl Ascorbate, Citrus Grandis (Grapefruit) Peel Oil, Tocopheryl Acetate, PPG-12/SMDI Copolymer, Limonene, Citral, Linalool, Geraniol.

This list of ingredients may be subject to change, please consult the packaging of the product purchased.

See more...

Rated 3 out of 5 by from Good but. . . [This review was collected as part of a promotion.] I love serums with vitamin C and I have tried many different brands. This serum has a very unique consistency due to its oiliness. I should be able to use my serum underneath my cream. This however is too heavy and it takes a long time to sink in before I can apply moisturiser and my skin is very dry. I would not recommend this to someone with an oily skin.
Date published: 2026-05-13
Rated 4 out of 5 by from Impressed so far [This review was collected as part of a promotion.] I'm new to vitamin C serums and this one seems to be doing a decent job of brightening my complexion. It's non drying on my sensitive and dehydrated skin, however it does leave a slight residue and adds a little shine. The good news is that it sits well under my matte SPF which means I can continue using it. Next time I'll probably go for the Luxe version since I had no adverse reactions to this weaker formula.
Date published: 2026-05-13
Rated 5 out of 5 by from An extra layer of sun protection [This review was collected as part of a promotion.] I find this one the best for my skin, without being too strong. My skin looks more radiant and I like to use it as an extra layer of protection against the sun.
Date published: 2026-05-13
Rated 3 out of 5 by from Good product but doesn’t suit my skin [This review was collected as part of a promotion.] A nice serum that leaves your skin feeling hydrated without residue. I have very sensitive skin so find that it can leaves my face looking flushed and slightly red.
Date published: 2026-05-12
Rated 5 out of 5 by from Beautiful Glow and Amazing Scent [This review was collected as part of a promotion.] I use this serum every morning after toner and absolutely love it. It needs a minute or two to fully absorb, but after that my skin feels comfortable, smooth and never greasy. There’s no heavy film at all. The scent is amazing — fresh, uplifting and honestly gives me such a nice mood boost in the morning. After it absorbs, I apply my SPF and everything layers beautifully. My skin looks healthy, radiant and glowing.
Date published: 2026-05-11
Rated 5 out of 5 by from Long time user [This review was collected as part of a promotion.] Been using this for several years ,just another great product that works.
Date published: 2026-05-10
Rated 5 out of 5 by from Great [This review was collected as part of a promotion.] Gentle and effective. I am very happy with this product.
Date published: 2026-05-08
Rated 5 out of 5 by from 10/10 [This review was collected as part of a promotion.] Medik8 C-Tetra has quickly become a staple in my skincare routine. The lightweight, silky formula absorbs into my skin without leaving any greasy residue but leaves me with a lovely glow. After a few weeks of consistent application, I noticed a visible improvement in my skin’s brightness - it looked radiant, even-toned, and healthy. I’ve also received several compliments on how fresh and glowing my skin looks. It has been gentle on my skin with no irritation following daily use.
Date published: 2026-05-05
  • y_2026, m_5, d_15, h_13
  • bvseo_bulk, prod_bvrr, vn_bulk_3.0.43
  • cp_1, bvpage1
  • co_hasreviews, tv_60, tr_961
  • loc_en_GB, sid_92833, prod, sort_[SortEntry(order=SUBMISSION_TIME, direction=DESCENDING)]
  • clientName_sephora-uk
  • bvseo_sdk, p_sdk, 3.2.0
  • CLOUD, getReviews, 28.43ms
  • REVIEWS, PRODUCT

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
  • y_2026, m_5, d_15, h_13CST
  • bvseo_bulk, prod_bvqa, vn_bulk_3.0.43
  • cp_1, bvpage1
  • co_hasquestionsanswers, tq_3
  • loc_en_GB, sid_92833, prod, sort_[SortEntry(order=LAST_APPROVED_ANSWER_SUBMISSION_TIME, direction=DESCENDING)]
  • clientName_sephora-uk
  • bvseo_sdk, p_sdk, 3.2.0
  • CLOUD, getContent, 27.95ms
  • QUESTIONS, PRODUCT