CSA: vitamin C and sunscreen by day, vitamin A by night

Medik8

Shop by rangeAll 66 products

Medik8 is British skincare built on a simple philosophy it calls CSA: vitamin C and sunscreen every morning, vitamin A every night. Its Crystal Retinal serums pioneered stabilised retinaldehyde for faster results with less irritation, and every formula is designed to be introduced gradually so skin gets stronger, not sensitised.

Flawless Body is an authorised UK stockist. Every product is genuine, sourced direct from Medik8, and dispatched from our Stamford warehouse.

Authorised Medik8 stockist
Sourced direct, guaranteed genuine
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All things skin & hair since 2006
Based in Stamford, Lincolnshire

YOUR ROUTINE, MADE PERSONAL

Find your Medik8 routine

Answer a few questions about your skin, choose your budget and see your personalised product shortlist.

Flawless Body · Your routine

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Shop by range

Pick the step or concern you are shopping for, or use the finder further down if you are not sure.

Serums

Vitamin C, retinal and peptides

Serums

C-Tetra vitamin C by day, Crystal Retinal by night, Liquid Peptides and Hydr8 B5 in between: the heart of the Medik8 routine.

27 products Shop range
Moisturisers

Day and night

Moisturisers

Total Moisture Daily Facial Cream, Advanced Night Restore and Daily Radiance Vitamin C: hydration matched to the serum underneath.

17 products Shop range
Cleansers & Toners

Step one

Cleansers & Toners

Surface Radiance Cleanse, Clarifying Foam, Lipid-Balance Cleansing Oil and Daily Refresh Balancing Toner for every skin type.

13 products Shop range
Eyes & Lips

Delicate areas

Eyes & Lips

Crystal Retinal Ceramide Eye, Advanced Night Eye and Illuminating Eye Balm: retinal and peptide care for the eye area.

9 products Shop range
Direct Acids

Exfoliating tonics

Direct Acids

Press & Glow PHA tonic for daily use, Sleep Glycolic for overnight resurfacing and Press & Clear BHA for blemish-prone skin.

3 products Shop range
Sunscreen

The S in CSA

Sunscreen

Advanced Day Total Protect and Physical Sunscreen: high-factor daily protection with skincare benefits built in.

4 products Shop range

Routine duos

Complete your Medik8 routine

Pair proven Medik8 favourites in one simple routine.

Not sure where to start?

Find your Medik8 step by what your skin needs.

Lines and loss of firmness

Crystal Retinal at night, stepped up gradually from 1 to 24. Shop Serums →

Dullness and pigmentation

C-Tetra vitamin C every morning brightens and protects. Shop Serums →

Dehydrated skin

Hydr8 B5 hyaluronic serum under any moisturiser. Shop Serums →

Blemishes and congestion

Press & Clear BHA tonic and Clarifying Foam cleanser. Shop Direct Acids →

Tired eyes and fine lines

Retinal and peptide eye care in the same gradual system. Shop Eyes & Lips →

Daily protection

High-factor sunscreen that completes CSA. Shop Sunscreen →

Still unsure? Every product page lists the skin type and concern it suits under Key Benefits.

Medik8 buying guide: how to choose

Medik8 is a British skincare brand built around one routine, which it calls CSA: vitamin C and sunscreen in the morning, vitamin A at night. Almost every product in the range fits one of those steps, or supports them with hydration, peptides, gentle exfoliation or cleansing, so you can build a routine one product at a time.

Start with your skin concern

  • Fine lines and uneven texture: Crystal Retinal is an evening serum-cream with retinaldehyde, a form of vitamin A. We stock strengths 1, 3, 6, 10 and 20. Medik8 recommends strength 3 for new vitamin A users; strength 1 is the lowest, worth considering if your skin is sensitive.
  • Dullness: C-Tetra, with 7% stabilised vitamin C, is Medik8's introduction to vitamin C, including for sensitive skin. Super C Ferulic is its highest-strength vitamin C serum, with 30% vitamin C.
  • Dehydration: Hydr8 B5 Intense combines multi-weight hyaluronic acid with vitamin B5 and suits morning and evening use.
  • Expression lines: Liquid Peptides Advanced MP is Medik8's peptide serum, built on its Dual MiniProteins technology.
  • Blemishes and congestion: Press & Clear is a 2% BHA daily toner. For an everyday glow, Press & Glow uses a gentle PHA suitable for twice-daily use, even on sensitive skin.
  • Daily protection: Advanced Day Total Protect (SPF 30) and Advanced Day Ultimate Protect (SPF 50+) complete the morning step.

Introduce vitamin A slowly

Medik8 advises a patch test first, then two nights a week for two weeks, alternate nights for two weeks, and nightly use once your skin is comfortable. Wear sunscreen every morning, and avoid vitamin A during pregnancy or breastfeeding. Our guide to choosing a Crystal Retinal strength explains each step up.

Why buy Medik8 from Flawless Body

Flawless Body is an authorised UK Medik8 stockist, run alongside an aesthetic skin clinic established in 2006. Every product is genuine, sourced direct from Medik8 and dispatched from our warehouse in Stamford, Lincolnshire, with free standard UK delivery on orders from £30. Our customers rate us Excellent on Trustpilot.

Frequently asked questions

What makes Medik8 different from other skincare brands?
Created by scientists, this professional skincare line focuses on high-performance ingredients that deliver visible results while being gentle on the skin. The range is designed to tackle common concerns such as ageing, blemishes, and uneven tone.

Can Medik8 products be used on sensitive skin?
Yes, many formulas are suitable for sensitive or reactive skin. They're balanced with soothing ingredients like niacinamide and hyaluronic acid to minimise irritation and maintain hydration.

How long does it take to see results?
Results depend on your skin type and routine, but most people notice smoother, clearer skin within four weeks. Continued use improves tone, brightness, and overall texture.

What is the best way to include these products in my routine?
Start with a gentle cleanser, then apply serums or treatments before moisturiser and SPF. Introduce active ingredients like retinol slowly to allow your skin to adjust.

Is Medik8 cruelty free?
Yes, the company does not test on animals and is committed to ethical, sustainable, and vegan-friendly skincare practices.

You can read more about this in our blog post here.

Where can I buy genuine Medik8 in the UK?
Flawless Body is an authorised UK stockist of Medik8. Every product is sourced direct from Medik8, guaranteed genuine and dispatched from our warehouse in Stamford, Lincolnshire, with free standard UK delivery on orders from £30.

Which Crystal Retinal strength should I start with?
Medik8 recommends Crystal Retinal 3 if you are new to vitamin A. Crystal Retinal 1 (0.01% retinal) is the lowest strength and worth considering if your skin is sensitive. Build up slowly: two nights a week for two weeks, alternate nights for two weeks, then nightly as your skin allows, and only move up a strength once your skin is comfortable. Wear sunscreen every morning.

Our guide explains each strength: which Medik8 Crystal Retinal strength should I use?

What is the Medik8 CSA routine?
CSA is Medik8's routine in three letters: vitamin C and sunscreen in the morning, vitamin A at night. A simple version is C-Tetra vitamin C serum and Advanced Day Total Protect SPF 30 each morning, then Crystal Retinal at night followed by a moisturiser such as Advanced Night Restore, which is designed to work alongside retinol and retinal.
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