Medik8

Medik8 is a British skincare brand built on the philosophy of CSA: Vitamin C in the morning, Sunscreen every day, and Vitamin A at night. Every product is formulated with clinical-grade actives, backed by peer-reviewed research, and designed to deliver visible results without unnecessary irritation.

Practitioner-recommended. Evidence-led. No compromise.

now stocking medik8 at stratumclinic.co.uk

Medik8 — Advanced British Skincare Backed by Science

Medik8 is a British skincare brand built on one simple philosophy: CSA. That stands for vitamin C in the morning, Sunscreen every day, and vitamin A at night. It's a framework grounded in decades of dermatological research, and it forms the foundation of every effective anti-ageing and skin-health routine. Medik8's formulations are designed for maximum bioavailability — meaning the actives are delivered in forms your skin can actually use, at concentrations that make a measurable difference.

As an Independent Nurse Prescriber, I recommend Medik8 to patients who want a results-driven, evidence-based routine without the complexity of prescription-only systems. Their Crystal Retinal range (using retinaldehyde rather than retinol) is one of the most effective over-the-counter vitamin A options available in the UK. Combined with their stable vitamin C serums and lightweight SPFs, the full CSA routine delivers visible improvements in texture, tone, fine lines, and radiance — often within the first four to six weeks.

The Complete CSA Routine

Vitamin C Serum + Crystal Retinal + Daily SPF — Everything Your Skin Needs

Book a free written skin assessment and we'll build your personalised Medik8 CSA routine based on your skin type, concerns, and tolerance level. Purchase the full routine after your consultation to receive 10% off your entire order.

Book Free Skin Assessment

10% discount applied when purchasing the full CSA routine after consultation

Clinician's Recommendation

The standout range within Medik8 is Crystal Retinal. It uses retinaldehyde — a form of vitamin A that's up to 11 times more potent than standard retinol — and delivers it in a time-release system that minimises irritation. I recommend it to virtually every patient looking for anti-ageing, texture improvement, or overall skin quality. The strength progression system (1 through to 24) means you can start gently and build over time. For most patients, Crystal Retinal 3 or 6 is the ideal starting point.

— Mark Taylor, MSurg, INP, RMN

Key Ingredients in the Medik8 Range

  • Retinaldehyde (Crystal Retinal)

    Retinaldehyde is one step closer to retinoic acid than retinol on the vitamin A conversion pathway, making it significantly more effective without a prescription. Medik8's Crystal Retinal range stabilises retinaldehyde in a time-release system, delivering powerful anti-ageing and skin-renewal benefits with far less irritation than traditional retinoids. It accelerates cell turnover, boosts collagen synthesis, and improves texture and tone.

    Shop Crystal Retinal 

  • Vitamin C (Multiple Forms)

    Medik8 offers vitamin C in several bioavailable forms — from stable L-ascorbic acid to lipid-soluble tetrahexyldecyl ascorbate — so there's an option for every skin type and tolerance level. Vitamin C is a potent antioxidant that neutralises free radical damage, brightens skin tone, supports collagen production, and enhances the effectiveness of your SPF. It's the 'C' in the CSA philosophy and should be applied every morning.

    Shop Medik8 Vitamin C 

  • Hyaluronic Acid

    A naturally occurring molecule that can hold up to 1,000 times its weight in water. Medik8 uses multi-weight hyaluronic acid complexes that hydrate at multiple depths within the skin — from the surface to the deeper dermal layers. This plumps fine lines, improves skin texture, and creates a hydrated base that allows other actives (like vitamin C and retinaldehyde) to perform more effectively.

  • Advanced SPF Filters

    Medik8's sunscreens combine modern photostable UV filters with antioxidant-rich formulations that protect against both UVA and UVB radiation. Daily broad-spectrum SPF is the 'S' in the CSA philosophy — without it, the benefits of your vitamin C and vitamin A are compromised. Medik8's SPFs are lightweight, non-greasy, and designed to sit comfortably under makeup, so there's no excuse to skip this essential step.

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The CSA Philosophy — Your AM & PM Routine

AM (C + S): Cleanse → Vitamin C serum (e.g. C-Tetra or Super C Ferulic) → Hydrating serum if needed → Moisturiser → Broad-spectrum SPF 30–50. Vitamin C provides antioxidant protection throughout the day, and SPF prevents UV-induced damage and pigmentation.

PM (A): Double cleanse → Crystal Retinal (start on alternate nights, build to nightly use) → Hydrating night cream or barrier repair moisturiser. Retinaldehyde works overnight to accelerate cell turnover, stimulate collagen, and refine skin texture.

This three-product philosophy — vitamin C, sunscreen, vitamin A — is the most evidence-based approach to long-term skin health and anti-ageing. Start with the basics and build from there.

Book a Routine Consultation

Frequently Asked Questions About Medik8

What is the CSA philosophy?

CSA stands for vitamin C, Sunscreen, and vitamin A — the three most evidence-based actives in skincare. The idea is simple: vitamin C in the morning provides antioxidant defence and brightening, sunscreen protects against UV damage (the primary driver of premature ageing), and vitamin A at night accelerates cell turnover and stimulates collagen. Medik8 built their entire range around this philosophy, making it straightforward to build an effective routine without guesswork.

Why choose Medik8 over other skincare brands?

Medik8 stands out for three reasons: bioavailability, stability, and progressive formulation. They invest heavily in ensuring actives are delivered in forms your skin can actually absorb and use — not just impressive-sounding concentrations that sit on the surface. Their vitamin C serums are among the most stable on the market, and the Crystal Retinal range uses retinaldehyde (a more potent form of vitamin A than retinol) in a controlled-release system. As a UK-based brand, their formulations are developed for British skin types and climate conditions.

What strength Crystal Retinal should I start with?

If you're new to retinoids entirely, start with Crystal Retinal 1 or 3. If you've used retinol products before and tolerated them well, Crystal Retinal 6 is usually a good entry point. The strengths (1, 3, 6, 10, and 24) correspond to increasing concentrations of retinaldehyde. The goal is to start at a level your skin tolerates comfortably, use it consistently for 8–12 weeks, and then progress to the next strength. Jumping straight to a high strength typically causes unnecessary irritation without faster results. For patients seeking even stronger results, the r-Retinoate range offers a premium encapsulated option, or explore all our retinoids.

Can I use Medik8 products alongside Obagi?

Yes, with some planning. Many of our patients use Medik8 vitamin C serums in the morning alongside an Obagi system in the evening, or combine Medik8 SPF with an Obagi treatment protocol. The key is avoiding doubling up on strong actives — for example, using Crystal Retinal and a Advanced-Protocol Retinoid on the same night. During a consultation, we can build a combined routine that draws the best from both brands without overloading your skin.

Is Medik8 cruelty-free?

Yes. Medik8 is certified cruelty-free by Leaping Bunny and PETA. They do not test on animals at any stage of product development, and they require the same commitment from all their ingredient suppliers. The brand is also committed to sustainable packaging and has been progressively reducing plastic use across their range.

Learn More

Medik8 Crystal Retinal — The Complete UK Guide · Crystal Retinal Strengths & How to Progress · Vitamin C Serums: How to Choose the Right One

Not Sure Where to Start with Medik8?

Book a free written skin assessment with our clinician. We'll assess your skin, recommend the right CSA routine for your concerns, and help you choose the correct Crystal Retinal strength. Purchase your full routine after the consultation and receive 10% off your order.

Book Free Skin Assessment