I still remember my first dalliance with retinoids in my mid-twenties. It was a time marked by blind optimism and, evidently, a complete lack of research. With the confidence of someone who had probably skimmed half an article at the time, I dove headfirst into an aggressively potent serum I had found online, and what followed over the next fortnight can only be described as dermatological chaos. 

Yes, I'm talking about the dreaded purging stage. 

My skin peeled erratically, erupted in rashes, and my face began to erupt with blemishes I hadn't had since puberty. Unsurprisingly, I spent the next couple of years giving retinoids a very wide berth. 

But that was over a decade ago, and the retinoids landscape has since undergone quite a massive renaissance. Today's formulas are more sophisticated: graduated strengths, smoother textures, and far fewer opportunities to accidentally antagonise your own face. So when I decided to re-enter the arena, I did so with a little more humility and significantly better judgement, starting with Medik8's Crystal Retinal Serum. 

The truth is, it isn't about pushing your skin to its limits. Vitamin A use requires patience and understanding what your skin actually needs. I've been using retinoids for eight years, starting at the very lowest strength and gradually working my way up over time. The results have been undeniable: a more refined texture, a noticeable glow and a visible softening of the fine lines around my eyes. 

More recently, formulas like Medik8's Crystal Retinal collection, recently named the No.1 Retinal Serum Worldwide*, have redefined what retinoids can look like.  

Powered by retinaldehyde, a next-generation form of vitamin A proven to work 11x faster than traditional retinol**, and combined with a patented stability technology and thoughtful step-up system, they take much of the guesswork out of choosing the right strength. Effective vitamin A does not have to come at the cost of comfort. 

What is Retinal and What Does it Do? 

Retinal is a vitamin A derivative that works beneath the surface of the skin to help accelerate skin turnover and support collagen production. In practice, that means a smoother texture, brighter tone, reduced appearance of dark spots and a gradual softening of fine lines, making it one of the most effective long-term ingredients in any skincare routine. 

The Medik8 Crystal Retinal System 

What sets the Crystal Retinal range apart is its ladder of progressive strengths, from beginner to expert, allowing you to build tolerance gradually without overwhelming your skin. Each step increases in retinaldehyde concentration. For the full breakdown, see the guide at the bottom of this article. 

How to Progress Safely 

Only move up strengths once your skin feels fully comfortable with your current level and you have used a full tube consistently. When you are ready to increase, introduce the new strength gradually: twice a week for the first two weeks, then every other night for two weeks, then every night once your skin feels settled. 

Buffer your retinal with a hydrating, barrier-supporting moisturiser. Medik8's Advanced Night Restore cream, a ceramide-rich formula specifically designed to be used alongside vitamin A, works well here. SPF during the daytime is non-negotiable. 

It is also worth resisting the urge to rush. Skin that is pushed too quickly often reacts, setting you back further than if you had simply been patient. 

What If I Have Sensitive Skin? 

If you have sensitive skin, take an even slower approach. Start with Crystal Retinal 1 and limit use to once or twice a week, allowing your skin time to adjust. Apply a nourishing moisturiser before and after to support your skin barrier. 

Simplify the rest of your routine. Avoid layering retinal with other potent actives such as strong vitamin C or exfoliating acids until tolerance is established, and focus instead on hydrating, calming ingredients like ceramides, hyaluronic acid and niacinamide. SPF remains non-negotiable. 

If my first encounter with retinoids taught me anything, it is that good skincare is very much about restraint. The desire for overnight results is understandable, but with vitamin A, impatience is rarely rewarded. So whether you are a hesitant beginner or a returning sceptic, the takeaway is simple: start low, go slow and listen carefully to your skin.  

To begin your Vitamin A journey, find your Crystal Retinal match using Medik8's quiz.

*This piece is a paid partnership with Medik8.

The Ladder 

Crystal Retinal 1 (0.01%), Sensitive Starters
The gentlest entry point in the range, formulated specifically for sensitive or reactive skin types. Ideal if you are nervous about irritation or entirely new to retinoids. 

Crystal Retinal 3 (0.03%), Beginners
A step up, but still firmly beginner-friendly. Often considered the ideal starting point for most first-time users. 

Crystal Retinal 6 (0.06%), Regular Use
A gentle boost in results, ideal for those who have built up a tolerance to vitamin A. 

Crystal Retinal 10 (0.1%), Advanced Use
Works more rapidly on more visible signs of ageing such as deep lines and pigmentation. 

Crystal Retinal 20 (0.2%), Experienced Use
Best suited to those who have worked through the lower levels. Delivers accelerated results for more stubborn skin concerns such as uneven skin tone. 

Crystal Retinal 24 (0.24%), Expert Use
The highest strength in the range, reserved for seasoned users who have fully acclimatised their skin. Maximum potency for intense skin concerns. 

*Source: independent market research by Kline & Company analysing manufacturer-level retinal serum sales for 2025. To verify, visit medik8.com/claims  

**Source for 11x claim: G. Siegenthaler et al., Retinol and retinal metabolism, Biochemical Journal, 1990, 268, pp 371-378 

This article is part of a paid partnership with Medik8.