Medik8 was founded in 2009 by two brothers in the back of their father's pharmacy. Crystal Retinal is now the number one retinal serum worldwide. It is widely available in Ireland across Brown Thomas, Arnotts, McSharrys, and Meaghers. This guide covers what makes it different from standard retinol, how to start the Crystal Retinal ladder without irritation, and whether the price is justified for Irish shoppers.
Who Makes Medik8 and What Makes It Different
Medik8 was founded in 2009 by brothers Elliot and Daniel Isaacs — the first product was made in a small lab at the back of their father's pharmacy in the UK. That origin matters because it shaped the brand's philosophy from the start: pharmaceutical rigour applied to consumer skincare. Elliot and Daniel are scientists, not marketers, and the brand has consistently prioritised formulation over aesthetics.
Today Medik8 is one of only 66 beauty manufacturers worldwide to hold B Corp certification — a demanding social and environmental impact standard that covers supply chain, labour practices, carbon footprint, and community impact. The brand manufactures virtually everything in its own ISO-certified Innovation Centre outside London. It is 100% vegan and cruelty-free across its full retail and professional range.
What distinguishes Medik8 from other clinical skincare brands is the Crystal Retinal range — specifically the use of retinaldehyde rather than retinol as its vitamin A molecule. This distinction, while technical, has significant practical implications for how quickly Irish shoppers see results.
Retinal vs Retinol — Why It Matters for Irish Shoppers
All forms of vitamin A must convert to retinoic acid before the skin can use them. The number of conversion steps a molecule requires determines how efficient — and how fast-acting — it is. Retinol requires two conversion steps. Retinaldehyde (retinal) requires only one.
Research published in the Biochemical Journal by Siegenthaler et al. in 1990 — the study Medik8 cites for its 11x claim — demonstrated that retinaldehyde converts to retinoic acid significantly more efficiently than retinol, with results up to 11 times faster. This is not marketing language. It is the underlying biochemistry of the vitamin A pathway.
The practical result for Irish shoppers: you can expect to see improvements in skin texture, fine lines, and tone in a shorter timeframe with retinaldehyde than with retinol, at the same level of gentleness. Retinaldehyde is also the only form of vitamin A with direct antibacterial properties, making it effective for blemish-prone skin as well as anti-ageing concerns.
The reason retinaldehyde is not used by more brands is that it is notoriously unstable — it degrades quickly on exposure to light and air, losing potency before it can be effective on skin. Medik8's Crystal Retinal uses a patented crystal-shaped encapsulation system that stabilises the retinaldehyde molecule and releases it gradually on contact with skin, preserving potency to the last drop.
The Crystal Retinal Ladder — Which Strength to Start With in Ireland
Crystal Retinal comes in six progressive strengths from 0.01% to 0.24% retinaldehyde. The ladder system is one of Medik8's most sensible design decisions — for a market like Ireland where sensitive skin is common and retinoid-induced irritation is the most frequent reason people abandon vitamin A entirely, the ability to start at the gentlest possible concentration and build gradually is genuinely valuable.
| Product | Retinaldehyde % | Best For | Irish Price (approx.) |
|---|---|---|---|
| Crystal Retinal 1 | 0.01% | Very sensitive skin, rosacea-prone, first-time retinoid users | €48–€55 |
| Crystal Retinal 3 | 0.03% | New vitamin A users, sensitive skin, recommended starting point | €52–€58 |
| Crystal Retinal 6 | 0.06% | Regular vitamin A users, stepping up from CR3 | €58–€65 |
| Crystal Retinal 10 | 0.1% | Experienced vitamin A users, established tolerance | €65–€75 |
| Crystal Retinal 20 | 0.2% | Expert users, significant anti-ageing concern | €75–€85 |
| Crystal Retinal 24 | 0.24% | Clinic consultation only — highest strength available | Clinic pricing |
Medik8's recommended introduction protocol: use twice per week for the first two weeks, every other night for the next two weeks, then nightly. Finish each strength before moving to the next. This phasing approach reduces the irritation risk and allows the skin to build tolerance before increasing concentration.
For the majority of Irish first-time buyers, Crystal Retinal 3 is the right starting point. Crystal Retinal 1 is specifically for very sensitive skin types — rosacea-prone, post-procedure, or anyone who has previously experienced significant irritation with retinol. Jumping to CR6 or CR10 without prior vitamin A experience is the most common mistake and the most common reason for unnecessary irritation.
The Medik8 CSA Philosophy — Simplest Effective Skincare Routine
Medik8 built its entire product range around a three-step daily philosophy: C (Vitamin C) and S (Sunscreen) by day, A (Vitamin A) by night. Every product in the range maps onto one of these steps. It is the most evidence-based simplified routine framework in mainstream skincare — vitamin C, broad-spectrum SPF, and retinoid are the three categories with the strongest clinical backing for both prevention and correction of skin ageing.
In practice, the CSA routine for an Irish shopper looks like:
- Morning: Medik8 C-Tetra vitamin C serum (stable lipid-soluble form, suits most skin types) + Medik8 Advanced Day Total Protect SPF 50
- Evening: Gentle cleanser + Crystal Retinal at appropriate strength + moisturiser
This is genuinely minimalist for a clinical skincare brand and avoids the complexity of multi-step routines that many Irish shoppers find unsustainable to maintain long-term.
Other Medik8 Products Worth Considering for Irish Shoppers
Beyond Crystal Retinal, several other Medik8 products have strong reputations in the Irish skincare community:
- C-Tetra Advanced — A stable vitamin C serum using tetrahexyldecyl ascorbate, a lipid-soluble vitamin C form that penetrates more effectively than standard L-ascorbic acid and is better tolerated by sensitive skin. At around €62 for 30ml, it is priced within the premium vitamin C category but competes well with SkinCeuticals on formulation quality at a lower price point.
- Liquid Peptides — A multi-peptide treatment serum targeting multiple signs of ageing simultaneously. Well regarded by Irish facialists and clinic therapists as an addition to the CSA routine for more mature skin.
- Press & Glow PHA Toner — A gentle polyhydroxy acid exfoliating toner suited to sensitive skin. PHAs are the gentlest acid family, suitable for reactive and rosacea-prone skin types where AHAs or BHAs may be too irritating.
- Advanced Night Restore — A richer night cream that pairs with Crystal Retinal for dry or mature skin types that need more emollient support overnight alongside the retinaldehyde treatment.
Where to Buy Medik8 in Ireland and What It Costs
Medik8 has strong Irish distribution across both physical retail and online pharmacy channels:
- Brown Thomas — full range in-store and online, trained skincare consultants available at counter
- Arnotts — Henry Street Dublin, in-store and online
- McSharrys Pharmacy — full Medik8 range online, free delivery over €50
- Meaghers Pharmacy — strong Medik8 selection online with Irish delivery
- SkinShop.ie — 20% off first order, good range including Crystal Retinal
- Eden Skinstore — authorised Medik8 retailer, fast Irish delivery
- Space NK Ireland — full range online
Irish pricing for Crystal Retinal ranges from approximately €48 for CR1 to €85 for CR20. At this price point, the comparison is with SkinCeuticals, Paula's Choice, and premium pharmacy vitamin A treatments. For the retinaldehyde technology and the B Corp manufacturing standards, the pricing is competitive within the clinical skincare tier.
Is Medik8 Crystal Retinal Worth It for Irish Skin?
For anyone who has tried standard retinol and either not seen results quickly enough or experienced irritation that stopped them continuing, Crystal Retinal is a genuinely logical upgrade. The retinaldehyde molecule is more efficient, the encapsulation system is more stable than most competitor retinol products, and the graduated ladder system makes it the most sensibly structured vitamin A introduction programme available to Irish shoppers without a prescription.
Irish skin types that benefit most: those with dry or sensitive skin who found retinol too irritating in the past (start CR1 or CR3), those over 40 looking for measurable anti-ageing results from a vitamin A product, and those with blemish-prone skin who have not yet tried vitamin A (retinaldehyde's antibacterial properties add a specific benefit in this category).
The honest caveat: Medik8 is not the most affordable option in the vitamin A category. If budget is the primary consideration, a well-formulated 0.3% retinol product from The Inkey List at €12 will still deliver genuine results. Medik8 is the better science and the better formulation — but the baseline of "any good retinoid used consistently" is what matters most.
“The first Medik8 product was created in a tiny lab in the back of their father's pharmacy. Since then, Medik8 has had many more award-winning products to help maintain a youthful complexion.” — Medik8 brand history
Looking at clinical skincare more broadly? See our full guide to the best skincare brands available in Ireland.
Best Skincare Brands IrelandFrequently Asked Questions
Medik8 is available in Ireland from Brown Thomas (in-store and online), Arnotts, McSharrys Pharmacy, Meaghers Pharmacy, SkinShop.ie (20% off first order), Eden Skinstore, and Space NK Ireland. The full Crystal Retinal range is stocked at most of these retailers. Brown Thomas and Arnotts offer in-store consultations with trained skincare advisors.
Crystal Retinal uses retinaldehyde rather than retinol. Retinaldehyde requires only one conversion step to become retinoic acid — the biologically active form of vitamin A — while retinol requires two. Peer-reviewed research published in the Biochemical Journal demonstrates that retinaldehyde acts up to 11 times faster than retinol as a result. Both are equally gentle, but retinaldehyde delivers results significantly faster.
Crystal Retinal 3 (0.03% retinaldehyde) is the recommended starting point for new vitamin A users. Very sensitive or rosacea-prone skin should start with Crystal Retinal 1 (0.01%). Use twice per week for the first two weeks, every other night for two weeks, then nightly. Finish the full tube before considering moving to the next strength.
Yes. Medik8 is 100% vegan and cruelty-free across its complete retail and professional range — one of the few clinical skincare brands to achieve this across the full product portfolio. It is also B Corp certified, one of only 66 beauty manufacturers worldwide to hold this certification.
Yes, with appropriate starting strength and introduction protocol. Crystal Retinal 1 (0.01% retinaldehyde) was specifically developed for sensitive and reactive skin types. Start twice weekly, build slowly, and use a barrier-supporting moisturiser alongside. Many users with rosacea-prone skin find retinaldehyde better tolerated than retinol because of its faster conversion to retinoic acid — meaning less unconverted molecule sits on the skin causing potential irritation.
Beauty Shop Ireland
Beauty Shop Ireland is an independent editorial guide for Irish consumers. We research skincare brands, makeup, beauty devices, and red light therapy products available in Ireland — giving you honest, straightforward buying advice without the influencer spin.
Clinical References
- Siegenthaler G, Saurat JH, Ponec M. Retinol and retinal metabolism. Biochem J. 1990;268(2):371–378. Retinaldehyde to retinoic acid conversion efficiency vs retinol. PubMed 2363706
- Mukherjee S, Date A, Patravale V, et al. Retinoids in the treatment of skin aging: an overview of clinical efficacy and safety. Clin Interv Aging. 2006;1(4):327–348. PubMed 18046911
- Zasada M, Budzisz E. Retinoids: active molecules influencing skin structure formation in cosmetic and dermatological treatments. Postepy Dermatol Alergol. 2019;36(4):392–397. Retinoid mechanisms and clinical applications. PubMed 31616213