Medik8 Crystal Retinal 20 vs 24: which should you choose?

What actually changes between 20 and 24?

Retinal is short for retinaldehyde, a form of vitamin A. Both strengths target visible wrinkles, uneven tone, texture and loss of firmness, so 24 is not applying for a different job. The increase is 0.04 percentage points, or 20% more retinal relative to 20; that is a concentration calculation, not a promise of 20% better skin. Both use encapsulated retinal and stabilisation technology. Choose by strength and tolerance rather than assuming the higher number means a different texture. Check the selected strength's local price and packaging ingredients before buying, because regional formulas can differ.56

Are you ready for 20 or 24?

For 20, Medik8's specific progression advice is to use Crystal Retinal 10 comfortably every night for three months or complete two full tubes first. Its international strength guide also places 20 after two tubes of 10. Neither route makes 20 a beginner serum. For 24, the next step is at least one tube of 20 with established tolerance, not simply previous experience with an unrelated retinol product. Medik8 calls its strength system a ladder, but reaching the top is not a skincare qualification.236

If you are new to vitamin A or have sensitive skin, start with Crystal Retinal 1 or 3 instead. Dryness and redness can occur while adjusting, even with the range's hydrating formula. If those changes are already happening at your current strength, building tolerance comes before moving up. Medik8 recommends discussing the fit with a dermatologist when starting 24. Neither strength is recommended during pregnancy or breastfeeding.17

How do you introduce the higher strength?

1. 1Patch test before full application. Apply a small amount to the inside of your wrist and wait 24 hours to check for irritation.
2. 2Apply in the evening after cleansing, on clean, dry skin. Use two pumps over your face and neck and allow the serum to absorb.
3. 3Follow with moisturiser to help offset dryness as your skin adjusts.
4. 4Introduce the new strength gradually. Medik8's phase in schedule is twice weekly for two weeks, every other night for the next two weeks, then nightly.
5. 5Apply broad spectrum SPF 30 sunscreen the following morning and continue using sunscreen every morning.

A higher strength does not require adding more actives. Medik8 allows Crystal Retinal alongside other actives, including Press & Clear and Sleep Glycolic, but advises combining them thoughtfully to avoid overwhelming skin. The essential evening sequence remains cleansing, retinal and moisturiser.7

Will 24 work faster or give better results?

Allow four to twelve weeks to begin seeing vitamin A benefits. Medik8 positions 24 as the stronger option for expert users seeking further improvements in texture, brightness and firmness. There is no precise extra benefit to put beside its extra concentration. The range's advertised 20% reduction in wrinkle appearance belongs to Crystal Retinal 6, tested over twelve weeks, rather than a measured advantage of 24 over 20. Choose the next strength based on comfortable use of the previous one, not that headline percentage.245