Best Medik8 Vitamin C Serum: The Full Range Ranked

Medik8 makes four vitamin C products, and they are not interchangeable. C-TETRA sits at 7% and is built for sensitive or first-time users; C-Tetra Luxe doubles that to 14% and adds nourishing oils; Super C Ferulic goes up to 30% for advanced brightening needs; and Daily Radiance Vitamin C bakes a lower strength into a moisturiser with SPF30 built in. This guide ranks all four by who they actually suit, using only the ingredient and formulation facts Medik8 publishes on each product.

This page covers Medik8's own vitamin C range specifically. If you want a cross-brand shortlist that includes vitamin C serums from outside Medik8, our wider guide to the best vitamin C serums in the UK covers that ground instead — this page won't repeat it.

Quick-facts: the Medik8 vitamin C range at a glance

1. Medik8 C-TETRA — best for beginners and sensitive skin

C-TETRA is Medik8's entry point into vitamin C, built around 7% Tetrahexyldecyl Ascorbate — a stabilised, lipid-soluble form of vitamin C that Medik8 formulates to resist oxidising once opened. It's paired with Vitamin E for extra antioxidant support and carried in a jojoba seed oil base, which gives the serum a silky, oil-like texture and a natural citrus scent from grapefruit peel oil rather than added fragrance.

On texture, it sinks in without leaving a greasy film, which is why Medik8 positions it as a layer that sits comfortably under moisturiser and SPF. Medik8 lists it as suitable for all skin types, and specifically calls out sensitive skin and people who are new to vitamin C as the audience it's designed for.

Skip this one if: you're already comfortable with stronger actives and want a more noticeable brightening step — in that case, Super C Ferulic (below) is the better fit.

2. Medik8 C-Tetra Luxe — best for dry or pigmentation-prone skin

C-Tetra Luxe takes the same Tetrahexyldecyl Ascorbate technology as C-TETRA but doubles the concentration to 14%, and builds it into a richer formula alongside Optimised Red Ginseng, Maracuja Oil, Squalane and Vitamin F. Medik8 markets it as the more nourishing option in the range — the squalane and Vitamin F are there for barrier support and hydration on top of the vitamin C's brightening role, and Vitamin E is included again for antioxidant support.

Texture-wise it's velvety rather than watery, with the same fast-absorbing, non-greasy finish as C-TETRA, just with more slip. Medik8 recommends it for dry, dehydrated and sensitive skin, and for anyone specifically dealing with hyperpigmentation or uneven tone who wants a serum that also addresses dryness at the same time. It comes in both a full 30ml size and a 15ml travel size.

Skip this one if: your skin runs oily or combination and doesn't need the extra richness — C-TETRA or Super C Ferulic will feel lighter.

3. Medik8 Super C Ferulic — the strongest option, for mature or sun-damaged skin

Super C Ferulic is Medik8's most concentrated vitamin C, formulated with 30% Ethylated L-Ascorbic Acid alongside a Vitamin C, Vitamin E and Ferulic Acid antioxidant complex, plus Turmeric Root Extract for additional brightening support. The ethylated form of ascorbic acid is included specifically for stability, so the serum is designed to hold its potency from the first use to the last rather than degrading in the bottle.

The texture is dry-touch and fast-absorbing rather than oily, and Medik8 notes that a gentle warming or tingling sensation on application is normal and typically settles within seconds — a sign of the higher-strength ascorbic acid. Medik8 positions this as the serum for mature skin and for those already showing more advanced signs of sun exposure, wanting a stronger vitamin C step than C-TETRA or C-Tetra Luxe provide.

Skip this one if: you have sensitive skin. Medik8's own product guidance is explicit that Super C Ferulic is not recommended for sensitive skin types, and points sensitive-skin users toward C-TETRA instead.

4. Medik8 Daily Radiance Vitamin C — best 2-in-1 with SPF30

Daily Radiance Vitamin C isn't a serum — it's a moisturiser that combines 7% Tetrahexyldecyl Ascorbate with broad-spectrum SPF30, plus Hyaluronic Acid, Glycerin and Vitamin E for hydration and antioxidant support. It's included here because it's the simplest way to get vitamin C into a morning routine without adding a separate serum step before sunscreen.

The texture is a lightweight, cashmere-soft cream rather than a fluid serum, and Medik8 describes it as absorbing without a greasy residue, making it workable under makeup. It's positioned for all skin types, including sensitive skin, and specifically for anyone who wants to simplify a morning routine into fewer steps.

Skip this one if: you already use a dedicated SPF you like and don't want to combine your vitamin C and sun protection into a single product — a standalone serum such as C-TETRA gives you more control over each step.

How to choose between them

• New to vitamin C, or sensitive skin: start with C-TETRA.
• Dry, dehydrated, or dealing with uneven tone and want extra nourishment: C-Tetra Luxe.
• Experienced with actives, mature skin, or addressing more advanced sun-related concerns: Super C Ferulic — but not if your skin is sensitive.
• Want to simplify your morning routine into fewer products: Daily Radiance Vitamin C.

Fitting a Medik8 vitamin C product into your routine

Medik8 builds its wider range around what it calls the CSA Philosophy — vitamin C and SPF applied in the morning, vitamin A (retinoid) products applied at night. In practice, that means any of the three serums here are designed to go on cleansed skin in the morning, before moisturiser and sunscreen (Daily Radiance Vitamin C combines the moisturiser and SPF steps into one, so it's applied as your final morning step rather than under a separate SPF). As with any new active, it's worth patch testing and introducing a new vitamin C product gradually rather than starting daily use straight away.

Frequently asked questions

What's the difference between Medik8's vitamin C serums?

Mainly strength and format. C-TETRA (7%) and C-Tetra Luxe (14%) both use the same stabilised, oil-soluble Tetrahexyldecyl Ascorbate but at different concentrations, with Luxe adding richer oils. Super C Ferulic (30% Ethylated L-Ascorbic Acid) is a different, stronger form of vitamin C paired with ferulic acid. Daily Radiance Vitamin C uses the same 7% form as C-TETRA but built into a moisturiser with SPF30, rather than a standalone serum.

Which Medik8 vitamin C serum should a beginner start with?

C-TETRA. Medik8 formulates it specifically as the gentler entry point for people who are new to vitamin C, at the lowest concentration in the range.

Can I use a Medik8 vitamin C serum if I have sensitive skin?

C-TETRA and C-Tetra Luxe are both positioned by Medik8 as suitable for sensitive skin. Super C Ferulic is the exception — Medik8's own guidance says it isn't recommended for sensitive skin, and points toward C-TETRA instead. As with any new product, patch test first and introduce it gradually to see how your skin responds.

Is Medik8 Daily Radiance Vitamin C a replacement for a vitamin C serum?

It can be, if your priority is simplicity. It carries the same 7% vitamin C form as C-TETRA, built into a moisturiser with SPF30, so it covers the vitamin C and sun protection steps of a morning routine in one product rather than two.

Can I use Medik8 vitamin C if I'm pregnant or breastfeeding?

If you're pregnant or breastfeeding, please contact our team for advice before use.

Do I still need SPF if I'm using a Medik8 vitamin C serum?

Yes. C-TETRA, C-Tetra Luxe and Super C Ferulic are all serums, not sunscreens, and are designed to be followed by a separate SPF. Daily Radiance Vitamin C is the exception, since it includes broad-spectrum SPF30 in the same product.