Medik8's Crystal Retinal is a bestseller in the beauty industry, and it's currently on sale for Amazon Prime Day. Read on for our beauty writer's full review…
Since entering my late 20s, skincare has become my top priority. Gone are the days of roasting myself in the sun with nothing but carrot oil (cringe). Now, it’s all about religiously slathering on SPF 50, sticking to my carefully curated routine, and downing two litres of water from my emotional support Stanley bottle.
One of the perks of being a beauty journalist is testing an endless supply of cleansers, serums and SPFs - but one brand that’s taken up prime real estate on my bathroom shelf for years is Medik8. Known for its science-backed approach to skincare, focusing on formulations that deliver noticeable results, it’s no wonder why it’s built up such a huge fanbase, and the reason why my basket is always full with cult products, and new launches.
One product in particular which I rave about to anyone who will listen is Medik8’s Crystal Retinal (not to be mistaken for retinol). I started using this little tube of magic around two years ago, and haven’t looked back since. After noticing some fine lines and shadows creeping in around my forehead and frown area - I was recommended Medik’s Crystal Retinal to use as a preventive method before Botox even entered the chat.
Crystal Retinal is one of those products you try once… and then wonder how you ever did your routine without it. It’s the one that finally got me into vitamin A properly, thanks to its use of retinal (stronger than retinol but still gentle) and a clever patented delivery system that actually looks after your skin barrier. It’s part of Medik8’s signature CSA philosophy (vitamin C, sunscreen, vitamin A) and easily one of the brand’s most talked-about products - for good reason. The results genuinely speak for themselves.
Oh - and just in case you needed another sign to try it, Medik8’s Crystal Retinal is currently over 20% off for Amazon Prime Day. This stuff hardly goes on sale, so if you’ve been thinking about adding it to your routine (or upping your strengh), now’s the perfect time to go for it.
Medik8 Crystal Retinal: at a glance
- Tested by: Shani Cohen, GLAMOUR’s Beauty Commerce Writer.
- Price: Prices vary depending on the strength you choose. It starts at £45 full price, but for Prime Day, strength 1 (ideal for beginners) is down to £35. BUY NOW or browse more Prime Day beauty deals.
- Strengths: Available in a ladder system (from 1 to 20) so you can gradually build tolerance over time.
- Best for: Acne-prone skin or first-time retinal users.
- Key ingredients: Retinaldehyde, hyaluronic acid, glycerin, vitamin E.
- Pros:
- Ladder system helps you build up strength gradually.
- Perfect for sensitive skin or those new to retinal.
- Improves skin brightness and adds radiance. - Cons: May irritate if you start on too high a strength for your skin.
- Tube size: 30ml.
- Free from: Artificial fragrance, synthetic colours, parabens, alcohol.
How we test:
As a beauty journalist with six years’ experience (and a bathroom cabinet that could rival a Sephora stockroom), I’ve tested more skincare than I can count. But for me, testing doesn’t just mean slapping something on once and hoping for the best - I like to give products a proper road test. That means weeks, if not months, of consistent use. I look at everything: the ingredients, the texture, how it layers with other products, and how my skin responds over time.
When it comes to Medik8 Crystal Retinal, I’ve been using it for about two years now - long enough to know it’s not not just a fad. I’ll admit, I made the classic mistake of diving straight in with strength 10 (not my finest moment), and quickly learned why Medik8 recommends starting low and working your way up.
After a short break to rebuild my barrier, I switched to strength 3 and gradually built up tolerance, using it a few nights a week before making it a nightly staple. Now, I’m on a higher strength (6 to be exact) and my skin has fully adapted to it. It’s helped smooth fine lines, even out texture, and gives me that subtle brightness that makes everything - even makeup - sit better. I’ve recommended it to pretty much everyone I know, and even my brother, who used to splash his face with water and call it a day, is now converted. It’s that good.
What’s the difference between retinol and the retinal in this serum?
According to Daniel Isaacs, Director of Research at Medik8: “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.”
Medik8 Crystal Retinal: The sciencey bit
Not to be confused with retinol (trust me, they’re not the same), this clever serum uses retinaldehyde - a next-generation form of vitamin A that works up to 11 times faster than standard retinol. It speeds up cell turnover, fades fine lines, boosts radiance and makes you look like you've had a great night's sleep - even if that's not the case.
On top of retinal, the formula is loaded with hydrating hyaluronic acid, protective vitamin E (which also amps up the power of your vitamin C), and glycerin to keep everything soft and soothed.
Texture-wise, it’s a rich, creamy serum that sinks in quickly and layers like a dream under your night cream. Just remember; it’s for evenings only, and you must wear SPF the next morning. Non-negotiable.
Which Medik8 Crystal Retinal should I start with?
If you’re new to vitamin A (or have sensitive skin), it’s best to start with Medik8 Crystal Retinal 1 or 3. These lower strengths are designed to help your skin gradually build tolerance without irritation - and trust me, your skin barrier will thank you.
How I apply it:
I used two pumps on clean, dry skin a few nights a week to begin with, then built up to nightly use once my skin reacted well to it. I always follow with a good moisturiser (Charlotte Tilbury’s Magic Cream is my current go-to), and Supergoop! SPF the next morning is a must.
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…
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.
More Medik8 products to shop in the Amazon Prime Day sale:
- Medik8 Advanced Night Restore Cream - £45.60 (was £60)
- Medik8 C-Tetra Luxe Vitamin C Radiance Serum - £46.85 (was £59)
- Medik8 Hydr8 B5 Intense Hyaluronic Acid Serum - £47.20 (was £59)
- Medik8 Advance Day Ultimate Protect - £44.60 (was £59)
- Medik8 Total Moisture Daily Facial Cream - £36.48 (3was £48)
- Medik8 Lipid-Balance Cleansing Oil - £22 (was £29)
Up next, read our Associate Beauty Director's Medik8 C-Tetra Advanced review.
