# Medik8 Crystal Retinal

> Medik8 Crystal Retinal is a retinaldehyde night serum sold in six strengths, from Crystal Retinal 1 (0.01%) to Crystal Retinal 24 (0.24%), each 30ml and priced £45–£114 on Medik8 UK on 25 September 2026. Medik8 directs evening use, a gradual build-up and next-morning sunscreen, and advises avoiding vitamin A in pregnancy.

- Canonical: https://thecastindex.com/beauty/medik8-crystal-retinal
- Category: Skin prep
- Format: Retinal night serum
- Finish: Serum
- Best for: A graduated retinal routine, from first use to expert strength
- Official: https://www.medik8.com/products/crystal-retinal
- Reviewed: 2026-09-25
- Method: evidence-led desk review of official specifications — not an implied hands-on test

## Should you buy this?

The clearest retinal ladder in the UK: six numbered strengths from 0.01% to 0.24% retinaldehyde, each 30ml, from £45. Start low, follow Medik8’s build-up schedule and finish a tube before moving up. It is not strictly fragrance-free.

Skip this if you are pregnant or breastfeeding, want a strictly fragrance-free formula, or want a single low-cost bottle rather than a strength system.

An evening treatment with a clear strength ladder — kept to night routines so daytime base sits on settled skin.

## The formula

Crystal Retinal uses retinaldehyde (retinal), a retinoid one step closer to retinoic acid than retinol, in six numbered strengths from 0.01% to 0.24%. Medik8 pairs it with hyaluronic acid and vitamin E; squalane and two vitamin C derivatives also appear in the ingredient list.

The numbered system is the point: it lets a first-time user start low and move up only after finishing a tube. Crystal Retinal 24, added in 2024, is intended only for users who have completed Crystal Retinal 20.

## Who it’s for

Someone new to retinoids who wants a clear route from a low starting strength to an advanced one, and experienced users who prefer retinal to retinol.

## What should you check before buying?

Start with the lowest strength if you are new to vitamin A, and follow the brand’s build-up schedule. It is not fragrance-free in the strict sense: coumarin, tonka bean and vanilla extracts appear in the ingredient list. Medik8 advises avoiding vitamin A during pregnancy and breastfeeding; speak to a GP or midwife.

## How to use it

1. Apply two pumps to face and neck in the evening, after cleansing
2. Start twice a week for two weeks, then every other night for two weeks, then nightly, as Medik8 directs
3. Finish a tube before moving up a strength
4. Wear sunscreen the next morning

## Questions and answers

### Which Medik8 Crystal Retinal strength should I start with?

The range runs upwards from Crystal Retinal 1, and Medik8 advises finishing a tube before moving up. New retinoid users start at a low strength; Crystal Retinal 24 is only for users who have completed Crystal Retinal 20.

### Can I use Crystal Retinal while pregnant?

Medik8 generally recommends avoiding vitamin A while pregnant or breastfeeding and suggests speaking to your GP or midwife.

### Is retinal stronger than retinol?

Retinal is one step closer to retinoic acid, the form skin uses, so products use lower percentages. Compare strengths within the same retinoid rather than across retinal and retinol.

## Explore the category

https://thecastindex.com/beauty/category/skin-prep