Medik8 Crystal Retinal vs Intelligent Retinol TR: Which Vitamin A Serum Should You Choose?
Updated Aug 20, 2026
The Verdict
Both are well-formulated, evidence-informed vitamin A serums from the same brand, so the choice comes down to texture and how gradually you want to progress. Choose Crystal Retinal for the gentlest possible start, a six-strength ladder, and a cushiony, hydrating feel. Choose Intelligent Retinol TR for a lightweight, water-free, dry-touch serum and a shorter three-strength path.
Crystal Retinal and Intelligent Retinol TR are Medik8's two flagship overnight vitamin A serums, and both are staples of the brand's CSA routine. The core difference is the active form: Crystal Retinal uses retinaldehyde in a six-step strength ladder and a cushiony, hydrating texture, while Intelligent Retinol TR uses encapsulated retinol boosted with climbazole in a three-step ladder and a lightweight, water-free oil serum.
Quick facts
| Crystal Retinal | Intelligent Retinol TR | |
|---|---|---|
| Active form | Retinaldehyde (retinal) | Retinol, with climbazole |
| Texture | Mousse-like, cushiony serum-cream | Lightweight, dry-touch oil serum |
| Strength ladder | 6 steps (1, 3, 6, 10, 20, 24) | 3 steps (3TR, 6TR, 10TR) |
| Size | 30ml | 15ml |
| Price band | £40s–£100s, rising with strength | £30s–£50s, rising with strength |
How the two actives differ
Both products deliver vitamin A, but the active ingredient itself is different. Retinaldehyde (the active in Crystal Retinal) sits one step closer to biologically active retinoic acid than retinol does, so it converts more directly once it's in the skin. Retinol (the active in Intelligent Retinol TR) needs an extra conversion step, which is why Medik8 pairs it with climbazole, an ingredient formulated to help slow the breakdown of that converted vitamin A, and with Time Release Technology, which is designed to release the retinol gradually overnight rather than all at once.
In practice, this means the two serums aren't simply "strong" and "weak" versions of the same thing — they're two different technical approaches to overnight vitamin A delivery, and Medik8 positions both within its wider CSA philosophy alongside vitamin C and SPF.
Side-by-side comparison
| Crystal Retinal | Intelligent Retinol TR | |
|---|---|---|
| Format | Retinaldehyde with crystal encapsulation technology and a carrot seed oil complex | Encapsulated retinol with climbazole and Time Release Technology |
| Key supporting ingredients | Hyaluronic acid, vitamin E, glycerin | Squalane, vitamin E |
| Strengths available | 1, 3, 6, 10, 20, 24 (six steps) | 3TR, 6TR, 10TR (three steps) |
| Who it tends to suit | Those who want the gentlest possible entry point, a hydrating cushiony texture, or a very gradual strength ladder | Those who prefer a lightweight, water-free serum feel and a shorter path to a higher strength |
| Price band | £40s–£100s depending on strength (30ml) | £30s–£50s depending on strength (15ml) |
Who Crystal Retinal tends to suit
- Anyone who wants the most gradual possible introduction to vitamin A — the entry strength is the gentlest in Medik8's retinal range
- Skin that likes a nourishing, cushiony texture rather than a dry-touch oil
- People who want room to keep progressing over a longer period, thanks to the six-strength ladder
- Those who want hyaluronic acid and glycerin built into the formula for extra comfort
Who Intelligent Retinol TR tends to suit
- Anyone who prefers a lightweight, water-free, dry-touch serum that layers easily under moisturiser
- Those who want to reach a higher strength in fewer steps — three strengths versus Crystal Retinal's six
- People who like the idea of an overnight, time-released delivery paired with a squalane base
- Skin that's previously tolerated other retinol products comfortably
Strength ladders: how to choose your starting point
Both ranges are built as ladders, and Medik8's guidance for each is to start low and progress only once your skin has adjusted. With Crystal Retinal, that means starting at Crystal Retinal 1 or 3 for most first-time users, and working up to 6, 10, 20 or 24 over time as tolerance builds. With Intelligent Retinol TR, the recommended starting point is 3TR, moving up to 6TR and then 10TR once a full bottle has been used comfortably at nightly frequency.
If you're unsure which strength or which range to start with, our team can talk you through it — contact us for personalised guidance based on your skin history.
Texture and how each feels on skin
Crystal Retinal has a mousse-like lotion texture that settles into a cream-like serum on application, with a satin, comfortable finish. It's designed to feel nourishing rather than drying, which is why Medik8 markets it as suitable across skin types, sensitivity included, when the right strength is chosen. The hyaluronic acid and glycerin in the base are there to help offset the dryness that vitamin A can sometimes cause, so it tends to suit people who find retinoids leave their skin feeling tight.
Intelligent Retinol TR is water-free and oil-based, with a silky, dry-touch finish that sinks in quickly and doesn't leave residue. The squalane base is a lightweight, skin-identical lipid rather than a humectant, so the finish is less "cushiony" and more "disappears fast." If you find cream-textured actives too rich, or you prefer a serum that vanishes before moisturiser, this is the more likely fit of the two.
What else is in the formula
Beyond the headline active, the supporting ingredients differ in a way that's worth knowing before you choose. Crystal Retinal is built around hyaluronic acid and glycerin, both humectants that draw moisture into the skin, plus a carrot seed oil complex that Medik8 uses to help stabilise the retinaldehyde itself. Intelligent Retinol TR is built around squalane, an emollient that sits closer to skin's own oils, plus climbazole and vitamin E. Neither formula contains added water in the Intelligent Retinol TR case, which is part of why the finish feels so different to Crystal Retinal's serum-cream texture.
Switching between the two
If you've already built tolerance on one Medik8 vitamin A serum and want to try the other, it's generally fine to switch once you're using your current product comfortably every night, rather than mid-way through building tolerance. Medik8's own strength guidance treats Crystal Retinal 6 as roughly comparable in experience to having used Intelligent Retinol TR previously, so that's a reasonable point to consider switching ranges if you want to try the other texture. As always, if you have any doubts about where to start, our team can advise based on your specific skin history.
Using either one safely
Both are night-time vitamin A treatments, so daily SPF the following morning matters regardless of which you choose. Introduce either gradually — a few nights a week to start, building to nightly use as your skin adjusts — and avoid combining them with other strong exfoliating actives on the same night until you know how your skin responds.
If you're pregnant or breastfeeding, please contact our team for advice before use.