While Crystal Retinal is my ride-or-die, Medik8’s newer launches have also impressed me recently. C-Tetra® Advanced is the brand’s upgraded vitamin C – lightweight, fast-absorbing and formulated to brighten and protect without messing with your skin barrier. It gives all the glow with none of the irritation some high-strength vitamin Cs can cause.

Then there’s Liquid Peptides Advanced Multi-Peptide – a clever, upgraded peptide serum that targets multiple signs of ageing at once, boosts collagen and supports the skin barrier. It’s designed to penetrate deeply for real results, and so far it’s been a solid addition to my routine on days when my skin needs extra love.

What the experts say:

To get the lowdown on why Medik8 Crystal Retinal is so loved — and how to use it properly — I put a few quick questions to Daniel Isaacs, Director of Research at Medik8. From the difference between retinal and retinol to who can actually use it (even if you have sensitive skin), here’s what he had to say…

What’s the difference between retinol and the retinal in this serum?

“There are three forms: Retinol, which is probably the most prevalent form in skincare. There are loads and loads of studies to support retinol, that’s the alcohol version of Vitamin A. Then you have Retinaldehyde, this is much less common than Retinol and only a few brands have it, but it is really well studied, and you get amazing results from this form in particular. Retinaldehyde is even more powerful than Retinol, it’s close to prescription strength but without the irritation associated with it. Finally, there is retinyl retinoate, this is a unique and exclusive form of Vitamin A, created by Medik8. It too has been proven in many independent studies. This form is truly special, as it is the only form of Vitamin A that can be used during the day because it doesn’t breakdown in sunlight. You get the benefits of the Vitamin A during the day and it’s also completely non irritating.”

Can someone with rosacea use retinol?

“Vitamin A is not off limits to sensitive skin, it just means you need to be more mindful of what you are using. In fact, vitamin A has some great benefits which can help sensitive and redness prone skin to increase its resilience. Vitamin A can help to strengthen the barrier function of the skin to minimise dryness and sensitivity and it can also be anti-inflammatory.”

What age should I start using retinaldehyde?

“There’s no set age, but many begin in their mid-20s to early 30s when early signs of ageing or skin concerns become noticeable. Starting early can help maintain skin health in the long run.”

Can I use retinaldehyde on sensitive skin?

“Medik8’s approach to laddering retinal is designed to help your skin gradually adjust to the potency of our iconic Crystal Retinal serum, which is available in six progressive strengths. Offering 0.01% to 0.24% retinaldehyde, there’s a strength for everyone, from beginners to expert users – even sensitive skin. This method allows users to ladder up their unique age-defying results over time. By starting with a lower concentration and slowly increasing over time, you can minimise irritation and achieve optimal age-defying results while supporting your skin’s tolerance. It ensures sustained, long-term benefits for smoother, firmer, and more youthful-looking skin.”

Medik8 Crystal Retinal: My verdict

The clinical claims for Medik8 Crystal Retinal speak for themselves: in an independent study on Crystal Retinal 6, 97% felt their skin looked more youthful, with a 20% reduction in visible wrinkles, and 100% said it felt gentle – all over just 12 weeks. So, does it live up to the hype in real life?

Despite my rookie error of jumping straight to strength 10 (my face did not thank me for that), this has become a constant repurchase for me – as you can see from my nearly empty tube in the pics. I’ve slowly worked my way up the strengths and the results have been worth every penny of the £69 price tag.

It sinks beautifully into my skin with no weird residue or cast, layers effortlessly with the rest of my routine and genuinely makes my skin look smoother and more even each morning. The harsh frown line that used to bother me? Gone. And my overall skin looks smoother and more balanced.

I apply it every evening, and it slots in so easily alongside my other favourites – it never pills or feels heavy, just does its thing quietly overnight.

In short; if you’re curious about retinal but nervous, start here, take it slow, pick your strength wisely and never, ever skip SPF. This little tube has earned its spot in my routine for good.

Up next, read our Associate Beauty Director’s Medik8 C-Tetra Advanced review.