Crystal Retinal 1 vs 3 vs 6 vs 10 vs 20 vs 24 — Which Strength Is Right for You?
If you've discovered Medik8's Crystal Retinal range, you're already ahead of most. Retinaldehyde (the active form of vitamin A used in Crystal Retinal) is one of the most effective retinoids available without a prescription — faster-acting than retinol, and better tolerated than cosmeceutical retinoid for most skin types.
But with six strengths to choose from — 1, 3, 6, 10, 20, and 24 — knowing where to start can feel overwhelming. This guide breaks it down clearly.
What Makes Crystal Retinal Different?
Crystal Retinal uses retinaldehyde, which sits one conversion step closer to retinoic acid (the active form your skin uses) than standard retinol. This means it works faster and more efficiently, with less irritation than clinically reviewed retinoid. The encapsulated delivery system also releases the active gradually, reducing sensitivity further.
The Six Strengths Explained
Crystal Retinal 1
The gentlest entry point into the range. Ideal for complete beginners to retinoids, those with very sensitive or reactive skin, or anyone who has experienced irritation with retinol products in the past. Starting here builds tolerance gradually and sets the foundation for progression.
Crystal Retinal 3
A step up from 1, still suitable for sensitive skin types. A good starting point if you've used low-strength retinol before without issues, or if you want to build tolerance a little faster than starting at 1.
Crystal Retinal 6
The most popular entry point for those new to retinaldehyde specifically. If you've used retinol regularly without irritation and want to step up to a more effective active, Crystal Retinal 6 is the natural starting point. Suitable for most skin types.
Crystal Retinal 10
For experienced retinoid users who have built tolerance and are ready for more visible results. At this strength, you'll see more pronounced improvements in fine lines, skin texture, and cell turnover. Not recommended as a starting point unless you have significant prior retinoid experience.
Crystal Retinal 20
A high-strength option for those who have worked up through the range and want to push results further. Expect faster cell turnover, more significant anti-ageing effects, and a higher likelihood of an initial adjustment period. Introduce slowly.
Crystal Retinal 24
The most potent in the range. Reserved for experienced retinoid users with well-established tolerance. At this strength, results are comparable to low-dose prescription retinoids. Not a starting point — this is where you progress to after consistent use at lower strengths.
How to Choose Your Starting Strength
Never used a retinoid before? Start at Crystal Retinal 1 or 3.
Used retinol occasionally without issues? Start at Crystal Retinal 6.
Regular retinol user, no irritation? Crystal Retinal 6 or 10.
Experienced retinoid user, ready to progress? Crystal Retinal 10 or 20.
Long-term retinoid user with high tolerance? Crystal Retinal 20 or 24.
How to Introduce Crystal Retinal
Regardless of which strength you start with, introduce retinaldehyde gradually. Begin using it every third night for the first two weeks, then every other night, then nightly as tolerated. Always apply to dry skin, follow with a good moisturiser, and use SPF every morning — retinoids increase photosensitivity.
Related Reading
- Medik8 Crystal Retinal: The Complete UK Guide
- Retinol vs cosmeceutical retinoid: Which Is Right For You?
- Best Eye Creams for Wrinkles & Dark Circles
A Note from Stratum
Every layer matters. At Stratum, every product we stock is personally selected based on clinical evidence and real-world results observed in practice. The Crystal Retinal range is one we recommend with confidence — but the right strength for you depends on your skin history and tolerance. If you're unsure, start lower and build up. Your skin will thank you.
Browse the full Crystal Retinal range at Stratum: Browse the Crystal Retinal Range